glob headers

Drone config

.drone.jsonnet

@@ -0,0 +1,253 @@
+# Copyright 2022 Peter Dimov
+# Distributed under the Boost Software License, Version 1.0.
+# https://www.boost.org/LICENSE_1_0.txt
+
+local library = "system";
+
+local triggers =
+{
+    branch: [ "master", "develop", "feature/*" ]
+};
+
+local ubsan = { UBSAN: '1', UBSAN_OPTIONS: 'print_stacktrace=1' };
+local asan = { ASAN: '1' };
+
+local linux_pipeline(name, image, environment, packages = "", sources = [], arch = "amd64") =
+{
+    name: name,
+    kind: "pipeline",
+    type: "docker",
+    trigger: triggers,
+    platform:
+    {
+        os: "linux",
+        arch: arch
+    },
+    steps:
+    [
+        {
+            name: "everything",
+            image: image,
+            environment: environment,
+            commands:
+            [
+                'set -e',
+                'wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | apt-key add -',
+            ] +
+            (if sources != [] then [ ('apt-add-repository "' + source + '"') for source in sources ] else []) +
+            (if packages != "" then [ 'apt-get update', 'apt-get -y install ' + packages ] else []) +
+            [
+                'export LIBRARY=' + library,
+                './.drone/drone.sh',
+            ]
+        }
+    ]
+};
+
+local macos_pipeline(name, environment, xcode_version = "12.2", osx_version = "catalina", arch = "amd64") =
+{
+    name: name,
+    kind: "pipeline",
+    type: "exec",
+    trigger: triggers,
+    platform: {
+        "os": "darwin",
+        "arch": arch
+    },
+    node: {
+        "os": osx_version
+    },
+    steps: [
+        {
+            name: "everything",
+            environment: environment + { "DEVELOPER_DIR": "/Applications/Xcode-" + xcode_version + ".app/Contents/Developer" },
+            commands:
+            [
+                'export LIBRARY=' + library,
+                './.drone/drone.sh',
+            ]
+        }
+    ]
+};
+
+local windows_pipeline(name, image, environment, arch = "amd64") =
+{
+    name: name,
+    kind: "pipeline",
+    type: "docker",
+    trigger: triggers,
+    platform:
+    {
+        os: "windows",
+        arch: arch
+    },
+    "steps":
+    [
+        {
+            name: "everything",
+            image: image,
+            environment: environment,
+            commands:
+            [
+                'cmd /C .drone\\\\drone.bat ' + library,
+            ]
+        }
+    ]
+};
+
+[
+    linux_pipeline(
+        "Linux 14.04 GCC 4.4",
+        "cppalliance/droneubuntu1404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-4.4', CXXSTD: '98,0x' },
+        "g++-4.4",
+        [ "ppa:ubuntu-toolchain-r/test" ],
+    ),
+
+    linux_pipeline(
+        "Linux 14.04 GCC 4.6",
+        "cppalliance/droneubuntu1404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-4.6', CXXSTD: '98,0x' },
+        "g++-4.6",
+        [ "ppa:ubuntu-toolchain-r/test" ],
+    ),
+
+    linux_pipeline(
+        "Linux 14.04 GCC 4.7",
+        "cppalliance/droneubuntu1404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-4.7', CXXSTD: '98,0x' },
+        "g++-4.7",
+        [ "ppa:ubuntu-toolchain-r/test" ],
+    ),
+
+    linux_pipeline(
+        "Linux 14.04 GCC 4.8*",
+        "cppalliance/droneubuntu1404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11' },
+    ),
+
+    linux_pipeline(
+        "Linux 14.04 GCC 4.9",
+        "cppalliance/droneubuntu1404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-4.9', CXXSTD: '03,11' },
+        "g++-4.9",
+        [ "ppa:ubuntu-toolchain-r/test" ],
+    ),
+
+    linux_pipeline(
+        "Linux 16.04 GCC 5*",
+        "cppalliance/droneubuntu1604:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14' },
+    ),
+
+    linux_pipeline(
+        "Linux 18.04 GCC 6",
+        "cppalliance/droneubuntu1804:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-6', CXXSTD: '03,11,14' },
+        "g++-6",
+    ),
+
+    linux_pipeline(
+        "Linux 18.04 GCC 7* 32/64",
+        "cppalliance/droneubuntu1804:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17', ADDRMD: '32,64' },
+    ),
+
+    linux_pipeline(
+        "Linux 18.04 GCC 8",
+        "cppalliance/droneubuntu1804:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-8', CXXSTD: '03,11,14,17' },
+        "g++-8",
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 GCC 9* 32",
+        "cppalliance/droneubuntu2004:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17,2a', ADDRMD: '32' },
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 GCC 9* 64",
+        "cppalliance/droneubuntu2004:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17,2a', ADDRMD: '64' },
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 GCC 9 ARM64 32/64",
+        "cppalliance/droneubuntu2004:multiarch",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17,2a', ADDRMD: '32,64' },
+        arch="arm64",
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 GCC 10 32 ASAN",
+        "cppalliance/droneubuntu2004:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-10', CXXSTD: '03,11,14,17,20', ADDRMD: '32' } + asan,
+        "g++-10-multilib",
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 GCC 10 64 ASAN",
+        "cppalliance/droneubuntu2004:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-10', CXXSTD: '03,11,14,17,20', ADDRMD: '64' } + asan,
+        "g++-10-multilib",
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 Clang 13",
+        "cppalliance/droneubuntu2004:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-13', CXXSTD: '03,11,14,17,20' },
+        "clang-13",
+        ["deb http://apt.llvm.org/focal/ llvm-toolchain-focal-13 main"],
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 Clang 14 UBSAN",
+        "cppalliance/droneubuntu2004:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-14', CXXSTD: '03,11,14,17,20' } + ubsan,
+        "clang-14",
+        ["deb http://apt.llvm.org/focal/ llvm-toolchain-focal-14 main"],
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 Clang 14 ASAN",
+        "cppalliance/droneubuntu2004:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-14', CXXSTD: '03,11,14,17,20' } + asan,
+        "clang-14",
+        ["deb http://apt.llvm.org/focal/ llvm-toolchain-focal-14 main"],
+    ),
+
+    macos_pipeline(
+        "MacOS 10.15 Xcode 12.2 UBSAN",
+        { TOOLSET: 'clang', COMPILER: 'clang++', CXXSTD: '03,11,14,1z' } + ubsan,
+    ),
+
+    macos_pipeline(
+        "MacOS 10.15 Xcode 12.2 ASAN",
+        { TOOLSET: 'clang', COMPILER: 'clang++', CXXSTD: '03,11,14,1z' } + asan,
+    ),
+
+    windows_pipeline(
+        "Windows VS2015 msvc-14.0",
+        "cppalliance/dronevs2015",
+        { TOOLSET: 'msvc-14.0', CXXSTD: '14,latest' },
+    ),
+
+    windows_pipeline(
+        "Windows VS2017 msvc-14.1",
+        "cppalliance/dronevs2017",
+        { TOOLSET: 'msvc-14.1', CXXSTD: '14,17,latest' },
+    ),
+
+    windows_pipeline(
+        "Windows VS2019 msvc-14.2",
+        "cppalliance/dronevs2019",
+        { TOOLSET: 'msvc-14.2', CXXSTD: '14,17,20,latest' },
+    ),
+
+    windows_pipeline(
+        "Windows VS2022 msvc-14.3",
+        "cppalliance/dronevs2022:1",
+        { TOOLSET: 'msvc-14.3', CXXSTD: '14,17,20,latest' },
+    ),
+]

.drone/drone.bat

@@ -0,0 +1,23 @@
+@REM Copyright 2022 Peter Dimov
+@REM Distributed under the Boost Software License, Version 1.0.
+@REM https://www.boost.org/LICENSE_1_0.txt
+
+@ECHO ON
+
+set LIBRARY=%1
+set DRONE_BUILD_DIR=%CD%
+
+set BOOST_BRANCH=develop
+if "%DRONE_BRANCH%" == "master" set BOOST_BRANCH=master
+cd ..
+git clone -b %BOOST_BRANCH% --depth 1 https://github.com/boostorg/boost.git boost-root
+cd boost-root
+git submodule update --init tools/boostdep
+xcopy /s /e /q %DRONE_BUILD_DIR% libs\%LIBRARY%\
+python tools/boostdep/depinst/depinst.py %LIBRARY%
+cmd /c bootstrap
+b2 -d0 headers
+
+if not "%CXXSTD%" == "" set CXXSTD=cxxstd=%CXXSTD%
+if not "%ADDRMD%" == "" set ADDRMD=address-model=%ADDRMD%
+b2 -j3 libs/%LIBRARY%/test toolset=%TOOLSET% %CXXSTD% %ADDRMD% variant=debug,release embed-manifest-via=linker

.drone/drone.sh

@@ -0,0 +1,24 @@
+#!/bin/bash
+
+# Copyright 2022 Peter Dimov
+# Distributed under the Boost Software License, Version 1.0.
+# https://www.boost.org/LICENSE_1_0.txt
+
+set -ex
+
+DRONE_BUILD_DIR=$(pwd)
+
+BOOST_BRANCH=develop
+if [ "$DRONE_BRANCH" = "master" ]; then BOOST_BRANCH=master; fi
+
+cd ..
+git clone -b $BOOST_BRANCH --depth 1 https://github.com/boostorg/boost.git boost-root
+cd boost-root
+git submodule update --init tools/boostdep
+cp -r $DRONE_BUILD_DIR/* libs/$LIBRARY
+python tools/boostdep/depinst/depinst.py $LIBRARY
+./bootstrap.sh
+./b2 -d0 headers
+
+echo "using $TOOLSET : : $COMPILER ;" > ~/user-config.jam
+./b2 -j3 libs/$LIBRARY/test toolset=$TOOLSET cxxstd=$CXXSTD variant=debug,release ${ADDRMD:+address-model=$ADDRMD} ${UBSAN:+undefined-sanitizer=norecover debug-symbols=on} ${ASAN:+address-sanitizer=norecover debug-symbols=on} ${LINKFLAGS:+linkflags=$LINKFLAGS}

.github/workflows/ci.yml

@@ -0,0 +1,372 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+      - develop
+      - feature/**
+
+env:
+  UBSAN_OPTIONS: print_stacktrace=1
+
+jobs:
+  posix:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - toolset: gcc-4.8
+            cxxstd: "03,11"
+            os: ubuntu-18.04
+            install: g++-4.8
+          - toolset: gcc-5
+            cxxstd: "03,11,14,1z"
+            os: ubuntu-18.04
+            install: g++-5
+          - toolset: gcc-6
+            cxxstd: "03,11,14,1z"
+            os: ubuntu-18.04
+            install: g++-6
+          - toolset: gcc-7
+            cxxstd: "03,11,14,17"
+            os: ubuntu-18.04
+          - toolset: gcc-8
+            cxxstd: "03,11,14,17,2a"
+            os: ubuntu-18.04
+            install: g++-8
+          - toolset: gcc-9
+            cxxstd: "03,11,14,17,2a"
+            os: ubuntu-20.04
+          - toolset: gcc-10
+            cxxstd: "03,11,14,17,2a"
+            os: ubuntu-20.04
+            install: g++-10
+          - toolset: gcc-11
+            cxxstd: "03,11,14,17,2a"
+            os: ubuntu-20.04
+            install: g++-11
+          - toolset: gcc-12
+            cxxstd: "03,11,14,17,20"
+            os: ubuntu-22.04
+            install: g++-12
+          - toolset: clang
+            compiler: clang++-3.9
+            cxxstd: "03,11,14"
+            os: ubuntu-18.04
+            install: clang-3.9
+          - toolset: clang
+            compiler: clang++-4.0
+            cxxstd: "03,11,14"
+            os: ubuntu-18.04
+            install: clang-4.0
+          - toolset: clang
+            compiler: clang++-5.0
+            cxxstd: "03,11,14,1z"
+            os: ubuntu-18.04
+            install: clang-5.0
+          - toolset: clang
+            compiler: clang++-6.0
+            cxxstd: "03,11,14,17"
+            os: ubuntu-18.04
+            install: clang-6.0
+          - toolset: clang
+            compiler: clang++-7
+            cxxstd: "03,11,14,17"
+            os: ubuntu-18.04
+            install: clang-7
+          - toolset: clang
+            compiler: clang++-8
+            cxxstd: "03,11,14,17"
+            os: ubuntu-20.04
+            install: clang-8
+          - toolset: clang
+            compiler: clang++-9
+            cxxstd: "03,11,14,17"
+            os: ubuntu-20.04
+            install: clang-9
+          - toolset: clang
+            compiler: clang++-10
+            cxxstd: "03,11,14,17,2a"
+            os: ubuntu-20.04
+          - toolset: clang
+            compiler: clang++-11
+            cxxstd: "03,11,14,17,2a"
+            os: ubuntu-20.04
+          - toolset: clang
+            compiler: clang++-12
+            cxxstd: "03,11,14,17,20"
+            os: ubuntu-20.04
+          - toolset: clang
+            compiler: clang++-13
+            cxxstd: "03,11,14,17,20"
+            os: ubuntu-22.04
+            install: clang-13
+          - toolset: clang
+            compiler: clang++-14
+            cxxstd: "03,11,14,17,20"
+            os: ubuntu-22.04
+            install: clang-14
+          - toolset: clang
+            cxxstd: "03,11,14,17,2a"
+            os: macos-10.15
+
+    runs-on: ${{matrix.os}}
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install packages
+        if: matrix.install
+        run: sudo apt install ${{matrix.install}}
+
+      - name: Setup Boost
+        run: |
+          echo GITHUB_REPOSITORY: $GITHUB_REPOSITORY
+          LIBRARY=${GITHUB_REPOSITORY#*/}
+          echo LIBRARY: $LIBRARY
+          echo "LIBRARY=$LIBRARY" >> $GITHUB_ENV
+          echo GITHUB_BASE_REF: $GITHUB_BASE_REF
+          echo GITHUB_REF: $GITHUB_REF
+          REF=${GITHUB_BASE_REF:-$GITHUB_REF}
+          REF=${REF#refs/heads/}
+          echo REF: $REF
+          BOOST_BRANCH=develop && [ "$REF" == "master" ] && BOOST_BRANCH=master || true
+          echo BOOST_BRANCH: $BOOST_BRANCH
+          cd ..
+          git clone -b $BOOST_BRANCH --depth 1 https://github.com/boostorg/boost.git boost-root
+          cd boost-root
+          cp -r $GITHUB_WORKSPACE/* libs/$LIBRARY
+          git submodule update --init tools/boostdep
+          python tools/boostdep/depinst/depinst.py --git_args "--jobs 3" $LIBRARY
+          ./bootstrap.sh
+          ./b2 -d0 headers
+
+      - name: Create user-config.jam
+        if: matrix.compiler
+        run: |
+          echo "using ${{matrix.toolset}} : : ${{matrix.compiler}} ;" > ~/user-config.jam
+
+      - name: Run tests
+        run: |
+          cd ../boost-root
+          ./b2 -j3 libs/$LIBRARY/test toolset=${{matrix.toolset}} cxxstd=${{matrix.cxxstd}} variant=debug,release
+
+  windows:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - toolset: msvc-14.0
+            cxxstd: "14"
+            addrmd: 32,64
+            os: windows-2019
+          - toolset: msvc-14.2
+            cxxstd: "14,17,20,latest"
+            addrmd: 32,64
+            os: windows-2019
+          - toolset: msvc-14.3
+            cxxstd: "14,17,20,latest"
+            addrmd: 32,64
+            os: windows-2022
+          - toolset: clang-win
+            cxxstd: "14,17,latest"
+            addrmd: 32,64
+            os: windows-2022
+          - toolset: gcc
+            cxxstd: "03,11,14,17,2a"
+            addrmd: 64
+            os: windows-2019
+
+    runs-on: ${{matrix.os}}
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Setup Boost
+        shell: cmd
+        run: |
+          echo GITHUB_REPOSITORY: %GITHUB_REPOSITORY%
+          for /f %%i in ("%GITHUB_REPOSITORY%") do set LIBRARY=%%~nxi
+          echo LIBRARY: %LIBRARY%
+          echo LIBRARY=%LIBRARY%>>%GITHUB_ENV%
+          echo GITHUB_BASE_REF: %GITHUB_BASE_REF%
+          echo GITHUB_REF: %GITHUB_REF%
+          if "%GITHUB_BASE_REF%" == "" set GITHUB_BASE_REF=%GITHUB_REF%
+          set BOOST_BRANCH=develop
+          for /f %%i in ("%GITHUB_BASE_REF%") do if "%%~nxi" == "master" set BOOST_BRANCH=master
+          echo BOOST_BRANCH: %BOOST_BRANCH%
+          cd ..
+          git clone -b %BOOST_BRANCH% --depth 1 https://github.com/boostorg/boost.git boost-root
+          cd boost-root
+          xcopy /s /e /q %GITHUB_WORKSPACE% libs\%LIBRARY%\
+          git submodule update --init tools/boostdep
+          python tools/boostdep/depinst/depinst.py --git_args "--jobs 3" %LIBRARY%
+          cmd /c bootstrap
+          b2 -d0 headers
+
+      - name: Run tests
+        shell: cmd
+        run: |
+          cd ../boost-root
+          b2 -j3 libs/%LIBRARY%/test toolset=${{matrix.toolset}} cxxstd=${{matrix.cxxstd}} address-model=${{matrix.addrmd}} variant=debug,release embed-manifest-via=linker
+
+  posix-cmake-subdir:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - os: ubuntu-18.04
+          - os: ubuntu-20.04
+          - os: ubuntu-22.04
+          - os: macos-10.15
+
+    runs-on: ${{matrix.os}}
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install packages
+        if: matrix.install
+        run: sudo apt install ${{matrix.install}}
+
+      - name: Setup Boost
+        run: |
+          echo GITHUB_REPOSITORY: $GITHUB_REPOSITORY
+          LIBRARY=${GITHUB_REPOSITORY#*/}
+          echo LIBRARY: $LIBRARY
+          echo "LIBRARY=$LIBRARY" >> $GITHUB_ENV
+          echo GITHUB_BASE_REF: $GITHUB_BASE_REF
+          echo GITHUB_REF: $GITHUB_REF
+          REF=${GITHUB_BASE_REF:-$GITHUB_REF}
+          REF=${REF#refs/heads/}
+          echo REF: $REF
+          BOOST_BRANCH=develop && [ "$REF" == "master" ] && BOOST_BRANCH=master || true
+          echo BOOST_BRANCH: $BOOST_BRANCH
+          cd ..
+          git clone -b $BOOST_BRANCH --depth 1 https://github.com/boostorg/boost.git boost-root
+          cd boost-root
+          cp -r $GITHUB_WORKSPACE/* libs/$LIBRARY
+          git submodule update --init tools/boostdep
+          python tools/boostdep/depinst/depinst.py --git_args "--jobs 3" $LIBRARY
+
+      - name: Use library with add_subdirectory
+        run: |
+          cd ../boost-root/libs/$LIBRARY/test/cmake_subdir_test
+          mkdir __build__ && cd __build__
+          cmake ..
+          cmake --build .
+          ctest --output-on-failure --no-tests=error
+
+  posix-cmake-install:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - os: ubuntu-18.04
+          - os: ubuntu-20.04
+          - os: ubuntu-22.04
+          - os: macos-10.15
+
+    runs-on: ${{matrix.os}}
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install packages
+        if: matrix.install
+        run: sudo apt install ${{matrix.install}}
+
+      - name: Setup Boost
+        run: |
+          echo GITHUB_REPOSITORY: $GITHUB_REPOSITORY
+          LIBRARY=${GITHUB_REPOSITORY#*/}
+          echo LIBRARY: $LIBRARY
+          echo "LIBRARY=$LIBRARY" >> $GITHUB_ENV
+          echo GITHUB_BASE_REF: $GITHUB_BASE_REF
+          echo GITHUB_REF: $GITHUB_REF
+          REF=${GITHUB_BASE_REF:-$GITHUB_REF}
+          REF=${REF#refs/heads/}
+          echo REF: $REF
+          BOOST_BRANCH=develop && [ "$REF" == "master" ] && BOOST_BRANCH=master || true
+          echo BOOST_BRANCH: $BOOST_BRANCH
+          cd ..
+          git clone -b $BOOST_BRANCH --depth 1 https://github.com/boostorg/boost.git boost-root
+          cd boost-root
+          cp -r $GITHUB_WORKSPACE/* libs/$LIBRARY
+          git submodule update --init tools/boostdep
+          python tools/boostdep/depinst/depinst.py --git_args "--jobs 3" $LIBRARY
+
+      - name: Configure
+        run: |
+          cd ../boost-root
+          mkdir __build__ && cd __build__
+          cmake -DBOOST_INCLUDE_LIBRARIES=$LIBRARY -DCMAKE_INSTALL_PREFIX=~/.local ..
+
+      - name: Install
+        run: |
+          cd ../boost-root/__build__
+          cmake --build . --target install
+
+      - name: Use the installed library
+        run: |
+          cd ../boost-root/libs/$LIBRARY/test/cmake_install_test && mkdir __build__ && cd __build__
+          cmake -DCMAKE_INSTALL_PREFIX=~/.local ..
+          cmake --build .
+          ctest --output-on-failure --no-tests=error
+
+  posix-cmake-test:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - os: ubuntu-18.04
+          - os: ubuntu-20.04
+          - os: ubuntu-22.04
+          - os: macos-10.15
+
+    runs-on: ${{matrix.os}}
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Install packages
+        if: matrix.install
+        run: sudo apt install ${{matrix.install}}
+
+      - name: Setup Boost
+        run: |
+          echo GITHUB_REPOSITORY: $GITHUB_REPOSITORY
+          LIBRARY=${GITHUB_REPOSITORY#*/}
+          echo LIBRARY: $LIBRARY
+          echo "LIBRARY=$LIBRARY" >> $GITHUB_ENV
+          echo GITHUB_BASE_REF: $GITHUB_BASE_REF
+          echo GITHUB_REF: $GITHUB_REF
+          REF=${GITHUB_BASE_REF:-$GITHUB_REF}
+          REF=${REF#refs/heads/}
+          echo REF: $REF
+          BOOST_BRANCH=develop && [ "$REF" == "master" ] && BOOST_BRANCH=master || true
+          echo BOOST_BRANCH: $BOOST_BRANCH
+          cd ..
+          git clone -b $BOOST_BRANCH --depth 1 https://github.com/boostorg/boost.git boost-root
+          cd boost-root
+          cp -r $GITHUB_WORKSPACE/* libs/$LIBRARY
+          git submodule update --init tools/boostdep
+          python tools/boostdep/depinst/depinst.py --git_args "--jobs 3" $LIBRARY
+
+      - name: Configure
+        run: |
+          cd ../boost-root
+          mkdir __build__ && cd __build__
+          cmake -DBOOST_INCLUDE_LIBRARIES=$LIBRARY -DBUILD_TESTING=ON ..
+
+      - name: Build tests
+        run: |
+          cd ../boost-root/__build__
+          cmake --build . --target tests
+
+      - name: Run tests
+        run: |
+          cd ../boost-root/__build__
+          ctest --output-on-failure --no-tests=error

.travis.yml

@@ -0,0 +1,218 @@
+# Copyright 2016-2019 Peter Dimov
+# Distributed under the Boost Software License, Version 1.0.
+# (See accompanying file LICENSE_1_0.txt or copy at http://boost.org/LICENSE_1_0.txt)
+
+language: cpp
+
+dist: xenial
+
+branches:
+  only:
+    - master
+    - develop
+    - /feature\/.*/
+
+env:
+  matrix:
+    - BOGUS_JOB=true
+
+matrix:
+
+  exclude:
+    - env: BOGUS_JOB=true
+
+  include:
+    - os: linux
+      compiler: g++
+      env: TOOLSET=gcc COMPILER=g++ CXXSTD=03,11,14 ADDRMD=32,64
+      addons:
+        apt:
+          packages:
+            - g++-multilib
+
+    - os: linux
+      arch: arm64
+      compiler: g++
+      env: TOOLSET=gcc COMPILER=g++ CXXSTD=03,11,14 ADDRMD=32,64
+
+    - os: linux
+      arch: ppc64le
+      compiler: g++
+      env: TOOLSET=gcc COMPILER=g++ CXXSTD=03,11,14
+
+    - os: linux
+      arch: s390x
+      compiler: g++
+      env: TOOLSET=gcc COMPILER=g++ CXXSTD=03,11,14 ADDRMD=32,64
+
+    - os: linux
+      compiler: g++-4.4
+      env: TOOLSET=gcc COMPILER=g++-4.4 CXXSTD=98,0x
+      addons:
+        apt:
+          packages:
+            - g++-4.4
+          sources:
+            - ubuntu-toolchain-r-test
+
+    - os: linux
+      compiler: g++-4.6
+      env: TOOLSET=gcc COMPILER=g++-4.6 CXXSTD=03,0x
+      addons:
+        apt:
+          packages:
+            - g++-4.6
+          sources:
+            - ubuntu-toolchain-r-test
+
+    - os: linux
+      dist: trusty
+      compiler: g++
+      env: TOOLSET=gcc COMPILER=g++ CXXSTD=03,11
+
+    - os: linux
+      dist: bionic
+      compiler: g++-11
+      env: UBSAN=1 TOOLSET=gcc COMPILER=g++-11 CXXSTD=03,11,14,17,20 UBSAN_OPTIONS=print_stacktrace=1 LINKFLAGS=-fuse-ld=gold
+      addons:
+        apt:
+          packages:
+            - g++-11
+          sources:
+            - sourceline: "ppa:ubuntu-toolchain-r/test"
+
+    - os: linux
+      dist: trusty
+      compiler: /usr/bin/clang++
+      env: TOOLSET=clang COMPILER=/usr/bin/clang++ CXXSTD=03,11
+      addons:
+        apt:
+          packages:
+            - clang-3.3
+
+    - os: linux
+      dist: trusty
+      compiler: /usr/bin/clang++
+      env: TOOLSET=clang COMPILER=/usr/bin/clang++ CXXSTD=03,11
+      addons:
+        apt:
+          packages:
+            - clang-3.4
+
+    - os: linux
+      compiler: clang++-12
+      env: UBSAN=1 TOOLSET=clang COMPILER=clang++-12 CXXSTD=03,11,14,17,20 UBSAN_OPTIONS=print_stacktrace=1
+      addons:
+        apt:
+          packages:
+            - clang-12
+          sources:
+            - ubuntu-toolchain-r-test
+            - sourceline: 'deb https://apt.llvm.org/xenial/ llvm-toolchain-xenial-12 main'
+              key_url: 'https://apt.llvm.org/llvm-snapshot.gpg.key'
+
+    - os: linux
+      dist: bionic
+      compiler: clang++-libc++
+      env: UBSAN=1 TOOLSET=clang COMPILER=clang++-libc++ CXXSTD=03,11,14,17,2a UBSAN_OPTIONS=print_stacktrace=1
+      addons:
+        apt:
+          packages:
+            - libc++-dev
+
+    - os: freebsd
+      compiler: clang++
+      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,17,2a
+
+    - os: osx
+      compiler: clang++
+      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z ADDRMD=32,64
+      osx_image: xcode7.3
+
+    - os: osx
+      compiler: clang++
+      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z ADDRMD=32,64
+      osx_image: xcode8.3
+
+    - os: osx
+      compiler: clang++
+      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z ADDRMD=32,64
+      osx_image: xcode9.4
+
+    - os: osx
+      compiler: clang++
+      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z
+      osx_image: xcode10.1
+
+    - os: osx
+      osx_image: xcode11.3
+      compiler: clang++
+      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z
+
+    - os: osx
+      osx_image: xcode12.2
+      compiler: clang++
+      env: UBSAN=1 TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z UBSAN_OPTIONS=print_stacktrace=1
+
+    - os: linux
+      env: CMAKE=1
+      script:
+        - mkdir __build__ && cd __build__
+        - cmake -DBOOST_INCLUDE_LIBRARIES=system -DBUILD_TESTING=ON ..
+        - cmake --build . --target tests
+        - ctest --output-on-failure --no-tests=error
+
+    - os: linux
+      env: CMAKE=1 BUILD_SHARED_LIBS=ON
+      script:
+        - mkdir __build__ && cd __build__
+        - cmake -DBUILD_SHARED_LIBS=ON -DBOOST_INCLUDE_LIBRARIES=system -DBUILD_TESTING=ON ..
+        - cmake --build . --target tests
+        - ctest --output-on-failure --no-tests=error
+
+    - os: linux
+      env: CMAKE_SUBDIR_TEST=1
+      install:
+        - BOOST_BRANCH=develop && [ "$TRAVIS_BRANCH" == "master" ] && BOOST_BRANCH=master || true
+        - git clone -b $BOOST_BRANCH https://github.com/boostorg/assert.git ../assert
+        - git clone -b $BOOST_BRANCH https://github.com/boostorg/config.git ../config
+        - git clone -b $BOOST_BRANCH https://github.com/boostorg/core.git ../core
+        - git clone -b $BOOST_BRANCH https://github.com/boostorg/predef.git ../predef
+        - git clone -b $BOOST_BRANCH https://github.com/boostorg/winapi.git ../winapi
+      script:
+      - cd test/cmake_subdir_test && mkdir __build__ && cd __build__
+      - cmake ..
+      - cmake --build .
+      - cmake --build . --target check
+
+    - os: linux
+      env: CMAKE_INSTALL=1
+      script:
+        - pip install --user cmake
+        - mkdir __build__ && cd __build__
+        - cmake -DBOOST_INCLUDE_LIBRARIES=system -DCMAKE_INSTALL_PREFIX=~/.local ..
+        - cmake --build . --target install
+        - cd ../libs/system/test/cmake_install_test && mkdir __build__ && cd __build__
+        - cmake -DCMAKE_INSTALL_PREFIX=~/.local ..
+        - cmake --build .
+        - cmake --build . --target check
+
+install:
+  - BOOST_BRANCH=develop && [ "$TRAVIS_BRANCH" == "master" ] && BOOST_BRANCH=master || true
+  - cd ..
+  - git clone -b $BOOST_BRANCH --depth 1 https://github.com/boostorg/boost.git boost-root
+  - cd boost-root
+  - git submodule update --init tools/boostdep
+  - cp -r $TRAVIS_BUILD_DIR/* libs/system
+  - python tools/boostdep/depinst/depinst.py system
+  - ./bootstrap.sh
+  - ./b2 headers
+
+script:
+  - |-
+    echo "using $TOOLSET : : $COMPILER ;" > ~/user-config.jam
+  - ./b2 -j3 libs/system/test toolset=$TOOLSET cxxstd=$CXXSTD variant=debug,release ${ADDRMD:+address-model=$ADDRMD} ${UBSAN:+cxxflags=-fsanitize=undefined cxxflags=-fno-sanitize-recover=undefined linkflags=-fsanitize=undefined define=UBSAN=1 debug-symbols=on} ${LINKFLAGS:+linkflags=$LINKFLAGS}
+
+notifications:
+  email:
+    on_success: always

CMakeLists.txt

@@ -0,0 +1,49 @@
+# Copyright 2018-2021 Peter Dimov
+# Distributed under the Boost Software License, Version 1.0.
+# See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt
+
+if(NOT DEFINED IDF_TARGET)
+
+cmake_minimum_required(VERSION 3.5...3.16)
+
+project(boost_system VERSION "${BOOST_SUPERPROJECT_VERSION}" LANGUAGES CXX)
+
+add_library(boost_system INTERFACE)
+add_library(Boost::system ALIAS boost_system)
+
+target_include_directories(boost_system INTERFACE include)
+
+target_link_libraries(boost_system
+  INTERFACE
+    Boost::assert
+    Boost::config
+    Boost::throw_exception
+    Boost::variant2
+    Boost::winapi
+)
+
+if(BUILD_TESTING)
+
+  add_subdirectory(test)
+
+endif()
+
+else()
+
+FILE(GLOB_RECURSE headers include/*.h include/*.hpp)
+
+idf_component_register(
+    SRCS
+        ${headers}
+    INCLUDE_DIRS
+        include
+    REQUIRES
+      boost_assert
+      boost_config
+      boost_throw_exception
+      boost_variant2
+#      boost_winapi
+)
+
+endif()
+

README.md

@@ -0,0 +1,25 @@
+# Boost.System
+
+The Boost.System library, part of [Boost C++ Libraries](https://boost.org),
+implements an extensible framework for error reporting in the form of an
+`error_code` class and supporting facilities.
+
+It has been proposed for the C++11 standard, has been accepted, and
+is now available as part of the standard library in the `<system_error>`
+header. However, the Boost implementation has continued to evolve and
+gain enhancements and additional functionality, such as support for
+attaching [source locations](https://www.boost.org/doc/libs/release/libs/assert/doc/html/assert.html#source_location_support)
+to `error_code`, and a `result<T>` class that can carry either a value
+or an error code.
+
+See [the documentation of System](http://boost.org/libs/system) for more
+information.
+
+Since `<system_error>` is a relatively undocumented portion of the C++
+standard library, the documentation of Boost.System may be useful to you
+even if you use the standard components.
+
+## License
+
+Distributed under the
+[Boost Software License, Version 1.0](http://boost.org/LICENSE_1_0.txt).

appveyor.yml

@@ -0,0 +1,62 @@
+# Copyright 2016-2019 Peter Dimov
+# Distributed under the Boost Software License, Version 1.0.
+# (See accompanying file LICENSE_1_0.txt or copy at http://boost.org/LICENSE_1_0.txt)
+
+version: 1.0.{build}-{branch}
+
+shallow_clone: true
+
+branches:
+  only:
+    - master
+    - develop
+    - /feature\/.*/
+
+environment:
+  matrix:
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      TOOLSET: msvc-9.0,msvc-10.0,msvc-11.0
+      ADDRMD: 32
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      TOOLSET: msvc-12.0,msvc-14.0
+      ADDRMD: 32,64
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
+      TOOLSET: msvc-14.1
+      CXXSTD: 14,17,latest
+      ADDRMD: 32,64
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      ADDPATH: C:\cygwin\bin;
+      TOOLSET: gcc
+      CXXSTD: 03,11,14,1z
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      ADDPATH: C:\cygwin64\bin;
+      TOOLSET: gcc
+      CXXSTD: 03,11,14,1z
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      ADDPATH: C:\mingw\bin;
+      TOOLSET: gcc
+      CXXSTD: 03,11,14,1z
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      ADDPATH: C:\mingw-w64\x86_64-6.3.0-posix-seh-rt_v5-rev1\mingw64\bin;
+      TOOLSET: gcc
+      CXXSTD: 03,11,14,1z
+
+install:
+  - set BOOST_BRANCH=develop
+  - if "%APPVEYOR_REPO_BRANCH%" == "master" set BOOST_BRANCH=master
+  - cd ..
+  - git clone -b %BOOST_BRANCH% --depth 1 https://github.com/boostorg/boost.git boost-root
+  - cd boost-root
+  - git submodule update --init tools/boostdep
+  - xcopy /s /e /q %APPVEYOR_BUILD_FOLDER% libs\system\
+  - python tools/boostdep/depinst/depinst.py system
+  - cmd /c bootstrap
+  - b2 -d0 headers
+
+build: off
+
+test_script:
+  - PATH=%ADDPATH%%PATH%
+  - if not "%CXXSTD%" == "" set CXXSTD=cxxstd=%CXXSTD%
+  - if not "%ADDRMD%" == "" set ADDRMD=address-model=%ADDRMD%
+  - b2 -j3 libs/system/test toolset=%TOOLSET% %CXXSTD% %ADDRMD% variant=debug,release embed-manifest-via=linker

build/Jamfile.v2

@@ -5,7 +5,7 @@
 # Distributed under the Boost Software License, Version 1.0.
 # (See accompanying file LICENSE_1_0.txt or www.boost.org/LICENSE_1_0.txt)
 
-# See library home page at http://www.boost.org/libs/system
+# See library home page at https://www.boost.org/libs/system
 
 project boost/system
     : source-location ../src
@@ -22,4 +22,4 @@ lib boost_system
      <link>static:<define>BOOST_SYSTEM_STATIC_LINK=1
    ;
 
-boost-install boost_system ;
+boost-install boost_system ;

doc/.gitignore

@@ -0,0 +1,2 @@
+/html/
+/pdf/

doc/Jamfile

@@ -0,0 +1,23 @@
+# Copyright 2017, 2018 Peter Dimov
+# 
+# Distributed under the Boost Software License, Version 1.0.
+# (See accompanying file LICENSE_1_0.txt or copy at
+# http://www.boost.org/LICENSE_1_0.txt)
+
+import asciidoctor ;
+
+html system.html : system.adoc ;
+
+install html_ : system.html : <location>html ;
+
+pdf system.pdf : system.adoc ;
+explicit system.pdf ;
+
+install pdf_ : system.pdf : <location>pdf ;
+explicit pdf_ ;
+
+###############################################################################
+alias boostdoc ;
+explicit boostdoc ;
+alias boostrelease : html_ ;
+explicit boostrelease ;

doc/index.html

@@ -1,147 +0,0 @@
-<html>
-
-<head>
-<meta http-equiv="Content-Language" content="en-us">
-<meta name="GENERATOR" content="Microsoft FrontPage 5.0">
-<meta name="ProgId" content="FrontPage.Editor.Document">
-<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
-<title>Boost System Library</title>
-<link rel="stylesheet" type="text/css" href="../../../doc/html/minimal.css">
-</head>
-
-<body>
-
-<table border="0" cellpadding="5" cellspacing="0" style="border-collapse: collapse" bordercolor="#111111">
-  <tr>
-    <td width="277">
-<a href="../../../index.html">
-<img src="../../../boost.png" alt="boost.png (6897 bytes)" align="middle" width="277" height="86" border="0"></a></td>
-    <td width="337" align="middle">
-    <font size="7">System Library</font>
-    </td>
-  </tr>
-</table>
-
-<table border="0" cellpadding="5" cellspacing="0" style="border-collapse: collapse" bordercolor="#111111" bgcolor="#D7EEFF" width="100%">
-  <tr>
-    <td><a href="../../../index.htm">Boost Home</a>&nbsp;&nbsp;&nbsp; <a href="index.html">
-    Library Home</a>&nbsp;&nbsp; Tutorial&nbsp;&nbsp; <a href="reference.html">
-    Reference</a></td>
-  </tr>
-</table>
-
-<table border="1" cellpadding="5" cellspacing="0" style="border-collapse: collapse" bordercolor="#111111" align="right">
-  <tr>
-    <td width="100%" bgcolor="#D7EEFF" align="center">
-      <i><b>Contents</b></i></td>
-  </tr>
-  <tr>
-    <td width="100%" bgcolor="#E8F5FF">
-      <a href="#Introduction">Introduction</a><br>
-      <a href="#Design_Rationale">Design Rationale</a><br>
-      <a href="#History">History</a><br>
-      <a href="#Acknowledgements">Acknowledgements</a>
-    </td>
-  </tr>
-  <tr>
-    <td width="100%" bgcolor="#D7EEFF" align="center">
-      <b><i>Headers</i></b></td>
-  </tr>
-  <tr>
-    <td width="100%" bgcolor="#E8F5FF">
-      <a href="reference.html#Header-error_code">&lt;boost/system/error_code.hpp&gt;</a><br>
-      <a href="reference.html#Header-system_error">
-      &lt;boost/system/system_error.hpp&gt;</a><br>
-      <a href="../../../boost/system/cygwin_error.hpp">
-      &lt;boost/system/cygwin_error.hpp&gt;</a><br>
-      <a href="../../../boost/system/linux_error.hpp">
-      &lt;boost/system/linux_error.hpp&gt;</a><br>
-      <a href="../../../boost/system/windows_error.hpp">
-      &lt;boost/system/windows_error.hpp&gt;</a></td>
-  </tr>
-</table>
-
-<h2><a name="Introduction">Introduction</a></h2>
-
-<p>Error conditions originating from the operating system or other low-level 
-application program interfaces (API's) are typically reported via an integer 
-representing an error code. When these low-level API calls are wrapped in 
-portable code, such as in a portable library, some users want to deal with the 
-error codes in portable ways. Other users need to get at the system specific 
-error codes, so they can deal with system specific needs. The Boost System 
-library provides simple, light-weight <a href="reference.html#Class-error_code">
-error_code</a> objects that encapsulate system-specific error code values, yet 
-also provide access to more abstract and portable error conditions via
-<a href="reference.html#Class-error_condition">error_condition</a> objects. 
-Because error_code objects can represent errors from sources other than the 
-operating system, including user-defined sources, each error_code and 
-error_condition has an associated <a href="reference.html#Class-error_category">
-error_category</a>.</p>
-
-<p>An exception class,&nbsp; <a href="reference.html#Class-system_error">
-system_error</a>, is provided. Derived from std::runtime_error, it captures the 
-underlying error_code for the problem causing the exception so that this 
-important information is not lost.</p>
-<p>While exceptions are the preferred C++ default error code reporting 
-mechanism, users of libraries dependent on low-level API's&nbsp;often need overloads 
-reporting error conditions via error code arguments and/or return values rather 
-than via throwing exceptions. Otherwise, when errors are not exceptional 
-occurrences and must be dealt with as they arise, programs become littered with 
-try/catch blocks, unreadable, and very inefficient. The Boost System library 
-supports both error reporting by exception and by error code.</p>
-<p>In addition to portable errors codes and conditions supported by the <code>
-error_code.hpp</code> header, system-specific headers support the Cygwin, Linux, 
-and Windows platforms. These headers are effectively no-ops if included for 
-platforms other than their intended target.</p>
-<h2><a name="Design_Rationale">Design Rationale</a></h2>
-<p>Class <code>error_code</code>&nbsp; and <code>error_condition</code> are designed as a value types so 
-they can be copied 
-without slicing and do not requiring heap allocation, but still have polymorphic 
-behavior based on the error category. This is achieved by abstract base class
-<code>error_category</code> supplying the polymorphic behavior, and <code>
-error_code</code> and <code>error_condition</code> containing a pointer to an object of a type derived from <code>
-error_category</code>.</p>
-<p>Many of the detailed design decisions were driven by the requirements that 
-users to be able to add additional error categories, and that it be no more 
-difficult to write portable code than system-specific code.</p>
-<p>The <code>operator&lt;&lt;</code> overload for <code>error_code</code> eliminates a 
-misleading conversion to bool in code like <code>cout &lt;&lt; ec</code>, where <code>
-ec</code> is of type <code>error_code</code>. It is also useful in its own 
-right.</p>
-<h2><a name="History">History</a></h2>
-<p><a href="http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1975.html">
-N1975</a>, Filesystem Library Proposal for TR2, accepted for Library Technical 
-Report 2 (TR2) at the Berlin meeting, included additional components to 
-supplement the Standard Library's Diagnostics clause. Since then, these error 
-reporting components have received wider public scrutiny and enhancements have 
-been made to the design. The enhanced version has been used by N2054, Networking 
-Library Proposal for TR2, demonstrating that these error reporting components 
-are useful beyond the original Filesystem Library.</p>
-<p>The original proposal viewed error categories as a binary choice between
-<code>errno</code> (i.e. POSIX-style) and the native operating system's error 
-codes. The proposed components now allow as many additional error categories as 
-are needed by either implementations or by users. The need to support additional 
-error categories, for example, occurs in some networking library implementations 
-because they are built on top of the POSIX <code>getaddrinfo</code> API that 
-uses error codes not based on <code>errno</code>.</p>
-<h2><a name="Acknowledgements">Acknowledgements</a></h2>
-<p>Christopher Kohlhoff and Peter Dimov made important contributions to the 
-design. Comments and suggestions were also received from Pavel Vozenilek, 
-Gennaro Prota, Dave Abrahams, Jeff Garland, Iain Hanson, Oliver Kowalke, and 
-Oleg Abrosimov. Christopher Kohlhoff suggested several improvements to the N2066 
-paper. Johan Nilsson's comments led to several of the refinements in N2066 .</p>
-<hr>
-
-<p>Revised 
-<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%B %d, %Y" startspan -->February 23, 2008<!--webbot bot="Timestamp" endspan i-checksum="41408" --> </font>
-</p>
-
-<p><EFBFBD> Copyright Beman Dawes, 1999</p>
-
-<p>Distributed under the Boost Software License, Version 1.0.
-(See file <a href="../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a>
-or&nbsp; <a href="http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>) </p>
-
-</body>
-
-</html>

doc/reference.html

@@ -1,844 +0,0 @@
-<html>
-
-<head>
-<meta http-equiv="Content-Language" content="en-us">
-<meta name="GENERATOR" content="Microsoft FrontPage 5.0">
-<meta name="ProgId" content="FrontPage.Editor.Document">
-<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">
-<title>System Library Reference</title>
-<link rel="stylesheet" type="text/css" href="../../../doc/html/minimal.css">
-</head>
-
-<body>
-
-<table border="0" cellpadding="5" cellspacing="0" style="border-collapse: collapse" bordercolor="#111111" width="637">
-  <tr>
-    <td width="277">
-<a href="../../../index.htm">
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-      <i><b>Contents</b></i></td>
-  </tr>
-  <tr>
-    <td width="100%" bgcolor="#E8F5FF">
-      <a href="#Introduction">Introduction</a><br>
-      <a href="#Macros">Macros</a><br>
-      <a href="#Deprecated-names">Deprecated names</a><br>
-      <a href="#Header-error_code">Header &lt;boost/system/error_code.hpp&gt;</a><br>
-      <a href="#Class-error_category">Class <code>error_category</code></a><br>
-      &nbsp;&nbsp;&nbsp;<a href="#Class-error_category-synopsis">Class <code>error_category</code> synopsis</a><br>
-      &nbsp;&nbsp;&nbsp;<a href="#Class-error_category-virtual-members">Class <code>error_category</code> virtual members</a><br>
-      &nbsp;&nbsp;&nbsp;<a href="#Class-error_category-non-virtual-members">Class <code>error_category</code> non-virtual members</a><br>
-&nbsp;&nbsp; <a href="#Class-error_category-non-member-functions">Class <code>error_category</code> 
-      non-member functions</a><br>
-      &nbsp;&nbsp;&nbsp;<a href="#Class-error_category-predefined-objects">Class <code>error_category</code> predefined objects</a><br>
-      <a href="#Class-error_code">Class <code>error_code</code></a><br>
-      &nbsp;&nbsp;&nbsp;<a href="#Class-error_code-synopsis">Class <code>error_code</code> synopsis</a><br>
-      &nbsp;&nbsp;&nbsp;<a href="#Class-error_code-constructors">Class <code>error_code</code> constructors</a><br>
-      &nbsp;&nbsp;&nbsp;<a href="#Class-error_code-modifiers">Class <code>error_code</code> modifiers</a><br>
-      &nbsp;&nbsp;&nbsp;<a href="#Class-error_code-observers">Class <code>error_code</code> observers</a><br>
-      <a href="#Class-error_condition</code>">Class <code>error_condition</code></a><br>
-      &nbsp;&nbsp;&nbsp;<a href="#Class-error_condition-synopsis">Class <code>error_condition</code> synopsis</a><br>
-      &nbsp;&nbsp;&nbsp;<a href="#Class-error_condition-constructors">Class <code>error_condition</code> constructors</a><br>
-      &nbsp;&nbsp;&nbsp;<a href="#Class-error_condition-modifiers">Class <code>error_condition</code> modifiers</a><br>
-      &nbsp;&nbsp;&nbsp;<a href="#Class-error_condition-observers">Class <code>error_condition</code> observers</a><br>
-      <a href="#throws-object"><code>throws</code> object</a><br>
-      <a href="#Semantics-of-throws">Semantics of <code>throws</code> object</a><br>
-      <a href="#Non-member-functions">Non-member functions</a><br>
-      <a href="#Header-system_error">Header &lt;boost/system/system_error.hpp&gt;</a><br>
-      &nbsp;&nbsp;&nbsp;<a href="#Class-system_error">Class <code>system_error</code></a><br>
-    </td>
-  </tr>
-</table>
-
-<h2><a name="Introduction">Introduction</a></h2>
-
-<p>This reference documentation describes components that&nbsp; 
-programs may use to report error conditions originating from the operating 
-system or other low-level application program interfaces.</p>
-<p>Boost.System library components never change the value of <code>
-errno</code>.</p>
-<h2><a name="Macros">Macros</a></h2>
-<p>Users may defined the following macros if desired. Sensible defaults are 
-provided, so users may ignore these macros if they prefer.</p>
-<table border="1" cellpadding="5" cellspacing="0" style="border-collapse: collapse" bordercolor="#111111">
-  <tr>
-    <td><b><i>Macro Name</i></b></td>
-    <td><b><i>Default</i></b></td>
-    <td><b><i>Effect if defined</i></b></td>
-  </tr>
-  <tr>
-    <td valign="top"><code>BOOST_WINDOWS_API</code></td>
-    <td valign="top">Defined if Windows is detected by Boost.System's automatic configuration 
-    code, otherwise not defined.</td>
-    <td valign="top">Implementation uses the Microsoft Windows native 
-    application program interface (API).</td>
-  </tr>
-  <tr>
-    <td valign="top"><code>BOOST_POSIX_API</code></td>
-    <td valign="top">Defined if Windows is not detected by Boost.System's automatic configuration 
-    code.</td>
-    <td valign="top">Implementation uses the POSIX native 
-    application program interface (API).</td>
-  </tr>
-  <tr>
-    <td valign="top"><code>BOOST_SYSTEM_DYN_LINK</code></td>
-    <td valign="top">Defined if <code>BOOST_ALL_DYN_LINK</code> is defined, 
-    otherwise not defined.</td>
-    <td valign="top">Boost.System library is dynamically linked. If not defined, 
-    static linking is assumed.</td>
-  </tr>
-  <tr>
-    <td valign="top"><code>BOOST_SYSTEM_NO_LIB</code></td>
-    <td valign="top">Defined if <code>BOOST_ALL_NO_LIB</code> is defined, 
-    otherwise not defined.</td>
-    <td valign="top">Boost.System library does not use the Boost auto-link 
-    facility.</td>
-  </tr>
-  <tr>
-    <td valign="top"><code>BOOST_SYSTEM_NO_DEPRECATED</code></td>
-    <td valign="top">Not defined.</td>
-    <td valign="top">Deprecated features are excluded.</td>
-  </tr>
-</table>
-<h2><a name="Deprecated-names">Deprecated names</a></h2>
-<p>In the process of adding Boost.System to C++0x standard library, some of the 
-names are being changed. To ease transition, Boost.System deprecates the old 
-names, but continues to provide them unless macro <code>BOOST_SYSTEM_NO_DEPRECATED</code> 
-is defined.</p>
-<table border="1" cellpadding="5" cellspacing="1" style="border-collapse: collapse" bordercolor="#111111">
-  <tr>
-    <td><b><i>Old name, now deprecated</i></b></td>
-    <td><b><i>New name</i></b></td>
-  </tr>
-  <tr>
-    <td><code>namespace posix</code></td>
-    <td><code>namespace errc</code></td>
-  </tr>
-  <tr>
-    <td><code>namespace posix_error</code></td>
-    <td><code>namespace errc</code></td>
-  </tr>
-  <tr>
-    <td><code>enum posix_errno</code></td>
-    <td><code>enum errc_t</code></td>
-  </tr>
-  <tr>
-    <td><code>get_posix_category()</code></td>
-    <td><code>get_generic_category()</code></td>
-  </tr>
-  <tr>
-    <td><code>posix_category</code></td>
-    <td><code>generic_category</code></td>
-  </tr>
-  <tr>
-    <td><code>errno_ecat</code></td>
-    <td><code>generic_category</code></td>
-  </tr>
-  <tr>
-    <td><code>native_ecat</code></td>
-    <td><code>system_category</code></td>
-  </tr>
-</table>
-<h2><a name="Header-error_code">Header &lt;boost/system/error_code.hpp&gt;</a></h2>
-<h3>&lt;boost/system/error_code.hpp&gt; synopsis</h3>
-<blockquote>
-<pre>namespace boost
-{
-  namespace system
-  {
-    class <a href="#Class-error_category">error_category</a>;
-    class <a href="#Class-error_code">error_code</a>;
-    class <a href="#Class-error_condition">error_condition</a>;
-
-    //  "Concept" helpers
-    template< class T="" >
-      struct is_error_code_enum { static const bool value = false; };
-
-    template< class T="" >
-      struct is_error_condition_enum { static const bool value = false; };
-
-    //  generic error_conditions
-    namespace errc
-    {
-      enum errc_t
-      {
-        success = 0,
-        address_family_not_supported,   //EAFNOSUPPORT
-        address_in_use,                 //EADDRINUSE
-        address_not_available,          //EADDRNOTAVAIL
-        already_connected,              //EISCONN
-        argument_list_too_long,         //E2BIG
-        argument_out_of_domain,         //EDOM
-        bad_address,                    //EFAULT
-        bad_file_descriptor,            //EBADF
-        bad_message,                    //EBADMSG
-        broken_pipe,                    //EPIPE
-        connection_aborted,             //ECONNABORTED
-        connection_already_in_progress, //EALREADY
-        connection_refused,             //ECONNREFUSED
-        connection_reset,               //ECONNRESET
-        cross_device_link,              //EXDEV
-        destination_address_required,   //EDESTADDRREQ
-        device_or_resource_busy,        //EBUSY
-        directory_not_empty,            //ENOTEMPTY
-        executable_format_error,        //ENOEXEC
-        file_exists,                    //EEXIST
-        file_too_large,                 //EFBIG
-        filename_too_long,              //ENAMETOOLONG
-        function_not_supported,         //ENOSYS
-        host_unreachable,               //EHOSTUNREACH
-        identifier_removed,             //EIDRM
-        illegal_byte_sequence,          //EILSEQ
-        inappropriate_io_control_operation,//ENOTTY
-        interrupted,                    //EINTR
-        invalid_argument,               //EINVAL
-        invalid_seek,                   //ESPIPE
-        io_error,                       //EIO
-        is_a_directory,                 //EISDIR
-        message_size,                   //EMSGSIZE
-        network_down,                   //ENETDOWN
-        network_reset,                  //ENETRESET
-        network_unreachable,            //ENETUNREACH
-        no_buffer_space,                //ENOBUFS
-        no_child_process,               //ECHILD
-        no_link,                        //ENOLINK
-        no_lock_available,              //ENOLCK
-        no_message_available,           //ENODATA
-        no_message,                     //ENOMSG
-        no_protocol_option,             //ENOPROTOOPT
-        no_space_on_device,             //ENOSPC
-        no_stream_resources,            //ENOSR
-        no_such_device_or_address,      //ENXIO
-        no_such_device,                 //ENODEV
-        no_such_file_or_directory,      //ENOENT
-        no_such_process,                //ESRCH
-        not_a_directory,                //ENOTDIR
-        not_a_socket,                   //ENOTSOCK
-        not_a_stream,                   //ENOSTR
-        not_connected,                  //ENOTCONN
-        not_enough_memory,              //ENOMEM
-        not_supported,                  //ENOTSUP
-        operation_canceled,             //ECANCELED
-        operation_in_progress,          //EINPROGRESS
-        operation_not_permitted,        //EPERM
-        operation_not_supported,        //EOPNOTSUPP
-        operation_would_block,          //EWOULDBLOCK
-        owner_dead,                     //EOWNERDEAD
-        permission_denied,              //EACCES
-        protocol_error,                 //EPROTO
-        protocol_not_supported,         //EPROTONOSUPPORT
-        read_only_file_system,          //EROFS
-        resource_deadlock_would_occur,  //EDEADLK
-        resource_unavailable_try_again, //EAGAIN
-        result_out_of_range,            //ERANGE
-        state_not_recoverable,          //ENOTRECOVERABLE
-        stream_timeout,                 //ETIME
-        text_file_busy,                 //ETXTBSY
-        timed_out,                      //ETIMEDOUT
-        too_many_files_open_in_system,  //ENFILE
-        too_many_files_open,            //EMFILE
-        too_many_links,                 //EMLINK
-        too_many_synbolic_link_levels,  //ELOOP
-        value_too_large,                //EOVERFLOW
-        wrong_protocol_type             //EPROTOTYPE
-      };
-
-    } // namespace errc
-
-    template<> struct is_error_condition_enum<posix::posix_errno>&lt;errc::errc_t&gt;
-      { static const bool value = true; };
-
-    // predefined error_code object used as &quot;throw on error&quot; tag
-    extern error_code <a href="#throws-object">throws</a>;
-
-    //  <a href="#Non-member-functions">non-member functions</a>
-
-    bool operator==( const error_code &amp; lhs, const error_code &amp; rhs );
-    bool operator==( const error_code &amp; code, const error_condition &amp; condition );
-    bool operator==( const error_condition &amp; condition, const error_code &amp; code );
-    bool operator==( const error_condition &amp; lhs, const error_condition &amp; rhs );
-
-    bool operator!=( const error_code &amp; lhs, const error_code &amp; rhs );
-    bool operator!=( const error_code &amp; code, const error_condition &amp; condition );
-    bool operator!=( const error_condition &amp; condition, const error_code &amp; code );
-    bool operator!=( const error_condition &amp; lhs, const error_condition &amp; rhs );
-
-    bool operator&lt;( const error_code &amp; lhs, const error_code &amp; rhs );
-    bool operator&lt;( const error_condition &amp; lhs, const error_condition &amp; rhs );
-
-    error_code make_error_code( errc::errc_t e );
-    error_condition make_error_condition( errc::errc_t e );
-
-    template &lt;class charT, class traits&gt;
-      std::basic_ostream&lt;charT,traits&gt;&amp;
-        operator&lt;&lt;( basic_ostream&lt;charT,traits&gt;&amp; os, const error_code &amp; ec );
-
-    size_t hash_value( const error_code &amp; ec );
-  }
-}</pre>
-</blockquote>
-<p>The value of each<code> errc_t</code> constant shall be the same as the 
-value of the <code>&lt;cerrno&gt;</code> macro shown in the above synopsis.</p>
-<p>Users may specialize <code>is_error_code_enum</code> and <code>
-is_error_condition_enum</code> templates to indicate that a type is eligible for 
-class <code>error_code</code> and <code>error_condition</code> automatic 
-conversions respectively.</p>
-
-<h2><a name="Class-error_category">Class <code>error_category</code></a></h2>
-<p>The class <code>error_category</code> defines the base class for types used 
-to identify the source and encoding of a particular category of error code.</p>
-<p><i>[Note:</i> Classes may be derived from <code>error_category</code> 
-to support additional categories of errors. <i>--end note]</i></p>
-<p>The class <code>error_category</code> serves as a base class for types used 
-to identify the source and encoding of a particular category of error code. 
-Classes may be derived from <code>error_category</code> to support categories of 
-errors in addition to those defined in the Boost System library. Such classes 
-shall behave as specified in this subclause. [<i> Note:</i> <code>error_category</code> 
-objects are passed by reference, and two such objects are equal if they have the 
-same address. This means that applications using custom <code>error_category</code> 
-types should create a single object of each such type. <i><EFBFBD>end note</i> ]</p>
-<h3><a name="Class-error_category-synopsis">Class <code>error_category</code> synopsis</a></h3>
-<blockquote>
-<pre>namespace boost
-{
-  namespace system
-  {
-    class error_category : public noncopyable
-    {
-    public:
-      virtual ~error_category();
-
-      virtual const char *     name() const = 0;
-      virtual string           message( int ev ) const = 0;
-      virtual error_condition  default_error_condition( int ev ) const;
-      virtual bool             equivalent( int code, const error_condition &amp; condition ) const;
-      virtual bool             equivalent( const error_code &amp; code, int condition ) const;
-
-      bool operator==( const error_category &amp; rhs ) const;
-      bool operator!=( const error_category &amp; rhs ) const;
-      bool operator&lt; ( const error_category &amp; rhs ) const;
-    };
-
-    const error_category &amp;  get_system_category();
-    const error_category &amp;  get_generic_category();
-
-    static const error_category &amp;  system_category = get_system_category();
-    static const error_category &amp;  generic_category = get_generic_category();
-  }
-}</pre>
-</blockquote>
-<h3><a name="Class-error_category-virtual-members">Class <code>error_category</code> virtual members</a></h3>
-<p>Classes derived from <code>error_category</code> shall behave as specified in 
-this subclause.</p>
-<pre>virtual const char * name() const=0;</pre>
-<blockquote>
-  <p><i>Returns: </i>a string naming the error category.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<pre>virtual string message( int ev ) const=0;</pre>
-<blockquote>
-  <p><i>Returns:</i> A string that describes the error denoted by
-  <code>ev</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<p><code>virtual error_condition default_error_condition( int ev ) const;</code></p>
-<blockquote>
-  <p><i>Returns:</i>&nbsp; <code>error_condition( ev, *this )</code>.</p>
-  <blockquote>
-    <p>&nbsp;[<i>--Note:</i> Derived classes will typically convert <code>ev</code> 
-    to some portable <code>error_category</code>, such as <code>generic_category</code>, 
-    and return it as an <code>error_condition</code> for that category. <i>--end 
-    note</i>]</p>
-  </blockquote>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<p><code>virtual bool equivalent( int code, const error_condition &amp; 
-condition ) 
-const;</code></p>
-<blockquote>
-  <p><i>Returns:</i> <code>default_error_condition( code ) == condition</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<p><code>virtual bool equivalent( const error_code &amp; code, int condition ) const;</code></p>
-<blockquote>
-  <p><i>Returns:</i> <code>*this == code.category() &amp;&amp; code.value() == condition</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<h3><a name="Class-error_category-non-virtual-members">Class <code>error_category</code> non-virtual members</a></h3>
-<p><code>bool operator==( const error_category &amp; rhs ) const;</code></p>
-<blockquote>
-<p><i>Returns:</i> <code>this == &amp;rhs</code>.</p>
-</blockquote>
-<p><code>bool operator!=( const error_category &amp; rhs ) const;</code></p>
-<blockquote>
-<p><i>Returns:</i> <code>this != &amp;rhs</code>.</p>
-</blockquote>
-
-<pre>bool operator&lt;( const error_category &amp; rhs ) const;</pre>
-<blockquote>
-  <p><i>Returns:</i> <code>std::less&lt;const error_category*&gt;()( this, &amp;rhs )</code>.</p>
-  <blockquote>
-    <p><i>[Note:</i> <code>std::less</code> provides a total ordering for 
-    pointers. <i>--end note]</i></p>
-  </blockquote>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<h3><a name="Class-error_category-non-member-functions">Class <code>error_category</code> 
-non-member functions</a></h3>
-<pre>const error_category &amp; get_system_category();</pre>
-<blockquote>
-  <p><i>Returns:</i> A reference to a <code>error_category</code> object 
-  identifying errors originating from the operating system.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<pre>const error_category &amp; get_generic_category();</pre>
-<blockquote>
-  <p><i>Returns:</i> A reference to a <code>error_category</code> object 
-  identifying portable error conditions.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<h3><a name="Class-error_category-predefined-objects">Class <code>error_category</code> 
-predefined objects</a></h3>
-<p>Predefined objects <code>system_category</code> 
-and <code>generic_category</code> identify system specific error codes and portable error conditions, respectively.</p>
-<h2><a name="Class-error_code">Class <code>
-error_code</code></a></h2>
-<p>The class <code>error_code</code> describes an object used to hold error code 
-values, such as those originating from the operating<br>
-system or other low-level application program interfaces. <i>[ Note: </i>Class
-<code>error_code</code> is an adjunct to error reporting by<br>
-exception. <i><EFBFBD>end note ]</i></p>
-<h3><a name="Class-error_code-synopsis">Class <code>
-error_code</code> synopsis</a></h3>
-<blockquote>
-<pre>namespace boost
-{
-  namespace system
-  {
-    class error_code {
-    public:
-
-      // constructors:
-      error_code();
-      error_code( val, const error_category &amp; cat );
-      template &lt;class <code>ErrorCodeEnum</code>&gt;
-        error_code(<code> ErrorCodeEnum</code> e,
-         typename enable_if&lt;is_error_code_enum&lt;<code>ErrorCodeEnum</code>&gt; &gt;::type* = 0);
-
-      // modifiers:
-      void assign( int val, const error_category &amp; cat );
-      template&lt;typename <code>ErrorCodeEnum</code>&gt;
-        typename enable_if&lt;is_error_code_enum&lt;<code>ErrorCodeEnum</code>&gt;, error_code&gt;::type &amp;
-          operator=( <code>ErrorCodeEnum</code> val );;
-      void clear();
-
-      // observers:
-      int                    value() const;
-      cont error_category &amp;  category() const;
-      error_condition        default_error_condition() const;
-      string                 message() const;
-      operator unspecified-bool-type() const;
-
-    private:
-      int val_;                     // <i>exposition only</i>
-      const error_category * cat_;  // <i>exposition only</i>
-    };
-  }
-}</pre>
-</blockquote>
-<h3><a name="Class-error_code-constructors">Class <code>
-error_code</code> constructors</a></h3>
-<pre>error_code();</pre>
-<blockquote>
-  <p><i>Effects: </i>Constructs an object of type <code>error_code</code>.</p>
-  <p><i>Postconditions:</i> <code>val_ == 0 &amp;&amp; cat_ == &amp;system_category</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<pre>error_code( int val, const error_category &amp; cat );</pre>
-<blockquote>
-  <p><i>Effects: </i>Constructs an object of type <code>error_code</code>.</p>
-  <p><i>Postconditions:</i> <code>val_ == val &amp;&amp; cat_ == &amp;cat</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<pre>template &lt;class <code>ErrorCodeEnum</code>&gt;
-  error_code(<code> errorCodeEnum</code> val,
-    typename enable_if&lt;is_error_code_enum&lt;<code>ErrorCodeEnum</code>&gt; &gt;::type* = 0);</pre>
-<blockquote>
-  <p><i>Effects: </i>Constructs an object of type <code>error_code</code>.</p>
-  <p><i>Postconditions:</i> <code>*this == make_error_code( val )</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<h3><a name="Class-error_code-modifiers">Class <code>
-error_code</code> modifiers</a></h3>
-<pre>void assign( int val, const error_category &amp; cat );</pre>
-<blockquote>
-  <p><i>Postconditions:</i> <code>val_ == val &amp;&amp; cat_ == &amp;cat</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<pre>template&lt;typename <code>ErrorCodeEnum</code>&gt;
-  typename enable_if&lt;is_error_code_enum&lt;<code>ErrorCodeEnum</code>&gt;, error_code&gt;::type &amp;
-    operator=( <code>ErrorCodeEnum</code> val );</pre>
-<blockquote>
-  <p><i>Postconditions:</i> <code>*this == make_error_code( val )</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<p><code>void clear();</code></p>
-<blockquote>
-  <p><i>postcondition:</i> <code>value() == 0 &amp;&amp; category() == generic_category</code></p>
-</blockquote>
-  <h3><a name="Class-error_code-observers">Class <code>
-error_code</code> observers</a></h3>
-  <p><code>int value() const;</code></p>
-<blockquote>
-<p><i>Returns:</i> <code>val_</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-  <p><code>const error_category &amp; category() const;</code></p>
-<blockquote>
-<p><i>Returns:</i> <code>*cat_</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-  <pre>error_condition default_error_condition() const;</pre>
-<blockquote>
-<p><i>Returns:</i>&nbsp; <code>category().default_error_condition( value())</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-  <p><code>string message() const;</code></p>
-<blockquote>
-<p><i>Returns:</i>&nbsp; <code>category().message( value())</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<p><code>operator <i>unspecified-bool-type</i>() const;</code></p>
-<blockquote>
-<p><i>Returns:</i> if <code>value() != 0</code>, returns a value that will evaluate
-<code>true</code> in a boolean context; otherwise, returns a value that will 
-evaluate <code>false</code> in a boolean context. The value type returned shall 
-not be convertible to <code>int</code>.</p>
-<p><i>Throws:</i> nothing.</p>
-<p><i>[Note: </i>This conversion can be used in contexts where a <code>bool</code> 
-is expected ( e.g., an <code>if</code> condition ); however, implicit conversions 
-( e.g., to <code>int</code>) that can occur with <code>bool</code> are not 
-allowed, eliminating some sources of user error. One possible implementation 
-choice for this type is pointer-to-member. <i>--end note ]</i></p>
-</blockquote>
-<h2><a name="Class-error_condition">Class <code>error_condition</code></a></h2>
-<p>The class <code>error_condition</code> describes an object used to hold 
-values identifying error conditions. <i>[ Note: </i><code>error_condition</code> 
-values are portable abstractions, while <code>error_code</code> values are 
-implementation specific. <i>--end note ]</i></p>
-<h3><a name="Class-error_condition-synopsis">Class <code>error_condition</code> synopsis</a></h3>
-<blockquote>
-<pre>namespace boost
-{
-  namespace system
-  {
-    class error_condition
-    {
-    public:
-
-      // constructors:
-      error_condition();
-      error_condition( int val, const error_category &amp; cat );
-      template &lt;class ErrorConditionEnum&gt;
-        error_condition( errorConditionEnum val,
-          typename enable_if&lt;is_error_condition_enum&lt;ErrorConditionEnum&gt; &gt;::type* = 0 );
-
-      // modifiers:
-      void assign( int val, const error_category &amp; cat );
-      template&lt;typename ErrorConditionEnum&gt;
-        typename enable_if&lt;is_error_condition_enum&lt;ErrorConditionEnum&gt;, error_code&gt;::type &amp;
-          operator=( ErrorConditionEnum val );
-      void clear();
-
-      // observers:
-      int value() const;
-      const error_category &amp; category() const;
-      string message() const;
-      operator unspecified-bool-type () const;
-
-    private:
-      int val_;                      // <i>exposition only</i>
-      const error_category * cat_;   // <i>exposition only</i>
-    };
-  }
-}</pre>
-</blockquote>
-<h3><a name="Class-error_condition-constructors">Class <code>error_condition</code> 
-constructors</a></h3>
-<pre>error_condition(); </pre>
-<blockquote>
-  <p><i>Effects:</i> Constructs an object of type <code>error_condition</code>.</p>
-  <p><i>Postconditions:</i> <code>val_ == 0 and cat_ == &amp;generic_category</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<pre>error_condition( int val, const error_category &amp; cat );</pre>
-<blockquote>
-  <p><i>Effects: </i>Constructs an object of type error_condition.</p>
-  <p><i>Postconditions:</i> <code>val_ == val and cat_ == &amp;cat</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<pre>template &lt;class ErrorConditionEnum&gt;
-  error_condition( errorConditionEnum val,
-    typename enable_if&lt;is_error_condition_enum&lt;ErrorConditionEnum&gt; &gt;::type* = 0 );</pre>
-<blockquote>
-  <p><i>Effects:</i> Constructs an object of type <code>error_condition</code>.</p>
-  <p><i>Postconditions:</i> <code>*this == make_error_condition( val )</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<h3><a name="Class-error_condition-modifiers">Class <code>error_condition</code> 
-modifiers</a></h3>
-<pre>void assign( int val, const error_category &amp; cat ); </pre>
-<blockquote>
-  <p><i>Postconditions:</i> <code>val_ == val and cat_ == &amp;cat</code>. </p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<pre>template&lt;typename ErrorConditionEnum&gt;
-  typename enable_if&lt;is_error_condition_enum&lt;ErrorConditionEnum&gt;, error_code&gt;::type &amp;
-    operator=( ErrorConditionEnum val );</pre>
-<blockquote>
-  <p><i>Postconditions:</i> <code>*this == make_error_condition( val )</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<p><code>void clear();</code></p>
-<blockquote>
-  <p><i>postcondition:</i> <code>value() == 0 &amp;&amp; category() == generic_category</code></p>
-</blockquote>
-<h3><a name="Class-error_condition-observers">Class <code>error_condition</code> 
-observers</a></h3>
-<pre>int value() const;</pre>
-<blockquote>
-  <p><i>Returns:</i> <code>val_</code>.</p>
-  <p><i>Throws:</i> Nothing</p>
-</blockquote>
-<pre>const error_category &amp; category() const;</pre>
-<blockquote>
-  <p><i>Returns:</i> <code>*cat_</code>.</p>
-  <p>Throws: Nothing.</p>
-</blockquote>
-<pre>string message() const;</pre>
-<blockquote>
-  <p><i>Returns:</i> <code>category().message( value() )</code>.</p>
-  <p><i>Throws:</i> Nothing.</p>
-</blockquote>
-<pre>operator unspecified-bool-type () const;</pre>
-<blockquote>
-  <p><i>Returns: </i>If <code>value() != 0</code>, returns a value that will 
-  evaluate <code>true</code> in a boolean context; otherwise, returns a value 
-  that will evaluate <code>false</code>. The return type shall not be 
-  convertible to <code>int</code>. </p>
-  <p><i>Throws:</i> Nothing.</p>
-  <p><i>&nbsp;[ Note:</i> This conversion can be used in contexts where a <code>bool</code> 
-  is expected ( e.g., an if condition ); however, implicit conversions ( e.g., to
-  <code>int</code>) that can occur with <code>bool</code> are not allowed, 
-  eliminating some sources of user error. One possible implementation choice for 
-  this type is pointer to member. <i>--end note</i> <i>]</i></p>
-</blockquote>
-  <h2><a name="throws-object"><code>throws</code> object</a></h2>
-  <pre>extern error_code throws;</pre>
-<p>The predefined <code>error_code</code> object <code>throws</code> is supplied 
-for use as a &quot;throw on error&quot; tag.</p>
-<h2><a name="Semantics-of-throws">Semantics of <code>throws</code></a> object</h2>
-<p>Functions that specify an argument in the form <code>error_code&amp; ec=throws</code>, 
-with appropriate namespace qualifiers, have the following error handling 
-semantics:</p>
-<blockquote>
-  <p><i>Postconditions:</i></p>
-  <blockquote>
-    <p>If <code>&amp;ec != &amp;throws</code> and an error occurred:</p>
-    <ul>
-      <li> <code>ec.value()</code> returns the implementation specific error 
-      number for the particular error that occurred.</li>
-      <li><code>ec.category()</code> returns the <code>
-    <a href="#Class-error_category">error_category</a></code> for <code>ec.value()</code>.</li>
-    </ul>
-    <p>if <code>&amp;ec != &amp;throws</code> and an error did not occur, <code>ec.clear()</code>.</p>
-  </blockquote>
-  <p><i>Throws:</i></p>
-  <blockquote>
-  <p>If an error occurs and <code>&amp;ec == &amp;throws</code>, throws an exception of type
-  <code><a href="#Class-system_error">system_error</a></code> or of a type 
-  derived from <code><a href="#Class-system_error">system_error</a></code>. The 
-  exception's <code>code()</code> member function returns a reference to an
-  <code>error_code</code> object with the behavior specified in <i>
-  Postconditions</i>.</p>
-  </blockquote>
-</blockquote>
-<h2><a name="Non-member-functions">Non-member functions</a></h2>
-  <pre>bool operator==( const error_code &amp; lhs, const error_code &amp; rhs );</pre>
-<blockquote>
-  <p><i>Returns:</i> <code>lhs.category() == rhs.category() &amp;&amp; lhs.value() == 
-  rhs.value()</code>.</p>
-  <p><i>Throws: </i>Nothing.</p>
-</blockquote>
-<pre>bool operator==( const error_code &amp; code, const error_condition &amp; condition );
-bool operator==( const error_condition &amp; condition, const error_code &amp; code );</pre>
-<blockquote>
-  <p><i>Returns:</i> <code>code.category().equivalent( code.value(), condition )<br>
-  || condition.category().equivalent( code, condition.value() )</code>.</p>
-  <p><i>Throws: </i>Nothing.</p>
-</blockquote>
-<pre>bool operator==( const error_condition &amp; lhs, const error_condition &amp; rhs );</pre>
-<blockquote>
-  <p><i>Returns:</i> <code>lhs.category() == rhs.category() &amp;&amp; lhs.value() == 
-  rhs.value()</code>.</p>
-  <p><i>Throws: </i>Nothing.</p>
-</blockquote>
-<pre>bool operator!=( const error_code &amp; lhs, const error_code &amp; rhs );</pre>
-<blockquote>
-  <p><i>Returns:</i> <code>!(lhs == rhs )</code>.</p>
-  <p><i>Throws: </i>Nothing.</p>
-</blockquote>
-<pre>bool operator!=( const error_code &amp; code, const error_condition &amp; condition );
-bool operator!=( const error_condition &amp; condition, const error_code &amp; code );</pre>
-<blockquote>
-  <p><i>Returns:</i><code> !( code ==&nbsp; condition )</code>.</p>
-  <p><i>Throws: </i>Nothing.</p>
-</blockquote>
-<pre>bool operator!=( const error_condition &amp; lhs, const error_condition &amp; rhs );</pre>
-<blockquote>
-  <p><i>Returns:</i> <code>!(lhs == rhs )</code>.</p>
-  <p><i>Throws: </i>Nothing.</p>
-</blockquote>
-<pre>bool operator&lt;( const error_code &amp; lhs, const error_code &amp; rhs );</pre>
-<blockquote>
-  <p><i>Returns:</i> <code>lhs.category() &lt; rhs.category()<br>
-  &nbsp; || (lhs.category() == rhs.category() &amp;&amp; lhs.value() &lt; rhs.value())</code>.</p>
-  <p><i>Throws: </i>Nothing.</p>
-</blockquote>
-<pre>bool operator&lt;( const error_condition &amp; lhs, const error_condition &amp; rhs );</pre>
-<blockquote>
-  <p><i>Returns:</i> <code>lhs.category() &lt; rhs.category()<br>
-  &nbsp; || (lhs.category() == rhs.category() &amp;&amp; lhs.value() &lt; rhs.value())</code>.</p>
-  <p><i>Throws: </i>Nothing.</p>
-</blockquote>
-<pre>error_code make_error_code( errc::errc_t e );</pre>
-<blockquote>
-  <p><i>Returns:</i> <code>error_code( e, generic_category)</code>.</p>
-</blockquote>
-<pre>error_condition make_error_condition( errc::errc_t e );</pre>
-<blockquote>
-  <p><i>Returns:</i> <code>error_condition( static_cast&lt;int&gt;( e ), generic_category)</code>.</p>
-</blockquote>
-
-<pre>template &lt;class charT, class traits&gt;
-  std::basic_ostream&lt;charT,traits&gt;&amp;
-    operator&lt;&lt;( basic_ostream&lt;charT,traits&gt;&amp; os, const error_code &amp; ec );</pre>
-<blockquote>
-<p><i>Effects:</i> <code>os &lt;&lt; ec.category().name() &lt;&lt; ':' &lt;&lt; ec.value()</code>.</p>
-<p><i>Returns:</i> <code>os</code>.</p>
-</blockquote>
-<pre>size_t <a name="hash_value">hash_value</a>( const error_code &amp; ec );</pre>
-<blockquote>
-  <p><i>Returns: </i>&nbsp;A hash value representing <code>ec</code>.</p>
-</blockquote>
-
-<h2><a name="Header-system_error">Header &lt;boost/system/system_error.hpp&gt;</a></h2>
-
-<h3><a name="Class-system_error">Class <code>
-system_error</code></a></h3>
-<p>The class <code>system_error</code> describes an exception object used to 
-report errors that have an associated <code><a href="#Class-error_code">error_code</a></code>. Such errors typically originate from operating system or other low-level 
-application program interfaces.</p>
-<blockquote>
-<pre>namespace boost
-{
-  namespace system
-  {
-    class system_error : public std::runtime_error
-    {
-    public:
-      system_error( error_code ec );
-      system_error( error_code ec, const char * what_arg );
-      system_error( error_code ec, const std::string &amp; what_arg );
-      system_error( int ev, const error_category &amp; ecat,
-                    const char * what_arg );
-      system_error( int ev, const error_category &amp; ecat,
-                    const std::string &amp; what_arg );
-      system_error( int ev, const error_category &amp; ecat);
-
-      const error_code &amp; code() const throw();
-      const char *       what() const throw();
-    };
-  }
-}</pre>
-</blockquote>
-<pre>system_error( error_code ec );</pre>
-<blockquote>
-  <p><i>Effects:</i> Constructs an object of class <code>system_error</code>.</p>
-  <p><i>Postcondition:</i> <code>code() == ec <br>
-&nbsp; &amp;&amp; std::strcmp( this-&gt;runtime_error::what(), &quot;&quot; ) == 0</code></p>
-</blockquote>
-<pre>system_error( error_code ec, const char * what_arg );</pre>
-<blockquote>
-  <p><i>Effects:</i> Constructs an object of class <code>system_error</code>.</p>
-  <p><i>Postcondition:</i> <code>code() == ec <br>
-&nbsp; &amp;&amp; std::strcmp( this-&gt;runtime_error::what(), what_arg ) == 0</code></p>
-</blockquote>
-<pre>system_error( error_code ec, const std::string &amp; what_arg );</pre>
-<blockquote>
-  <p><i>Effects:</i> Constructs an object of class <code>system_error</code>.</p>
-  <p><i>Postcondition:</i> <code>code() == ec <br>
-&nbsp; &amp;&amp; std::strcmp( this-&gt;runtime_error::what(), what_arg.c_str() ) == 0</code></p>
-</blockquote>
-<pre>system_error( int ev, const error_category &amp; ecat,
-             const char * what_arg );</pre>
-<blockquote>
-  <p><i>Effects:</i> Constructs an object of class <code>system_error</code>.</p>
-  <p><i>Postcondition:</i> <code>code() == error_code( ev, ecat )<br>
-&nbsp; &amp;&amp; std::strcmp( this-&gt;runtime_error::what(), what_arg ) == 0</code></p>
-</blockquote>
-<pre>system_error( int ev, const error_category &amp; ecat,
-             const std::string &amp; what_arg );</pre>
-<blockquote>
-  <p><i>Effects:</i> Constructs an object of class <code>system_error</code>.</p>
-  <p><i>Postcondition:</i> <code>code() == error_code( ev, ecat )<br>
-&nbsp; &amp;&amp; std::strcmp( this-&gt;runtime_error::what(), what_arg.c_str() ) == 0</code></p>
-</blockquote>
-<pre>system_error( int ev, const error_category &amp; ecat );</pre>
-<blockquote>
-  <p><i>Effects:</i> Constructs an object of class <code>system_error</code>.</p>
-  <p><i>Postcondition:</i> <code>code() == error_code( ev, ecat )<br>
-&nbsp; &amp;&amp; std::strcmp( this-&gt;runtime_error::what(), &quot;&quot; ) == 0</code></p>
-</blockquote>
-<pre>const error_code &amp; code() const;</pre>
-<blockquote>
-  <p><i>Returns:</i> <code>ec</code> or <code>error_code( ev, ecat )</code>, from 
-  the constructor, as appropriate.</p>
-</blockquote>
-<pre>const char * what() const;</pre>
-<blockquote>
-  <p><i>Returns: </i>A string incorporating <code>
-  this-&gt;runtime_error::what()</code> and <code>
-  code.message()</code>.</p>
-</blockquote>
-<hr>
-
-<p>Revised 
-<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%B %d, %Y" startspan -->October 11, 2008<!--webbot bot="Timestamp" endspan i-checksum="30976" --> </font>
-</p>
-
-<p><EFBFBD> Copyright Beman Dawes, 2006, 2007, 2008</p>
-
-<p>Distributed under the Boost Software License, Version 1.0. See
-<a href="http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a></p>
-
-</body>
-
-</html>

doc/system-docinfo-footer.html

@@ -0,0 +1,6 @@
+<style>
+
+*:not(pre)>code { background: none; color: #600000; }
+:not(pre):not([class^=L])>code { background: none; color: #600000; }
+
+</style>

doc/system.adoc

@@ -0,0 +1,30 @@
+////
+Copyright 2018 Peter Dimov
+
+Distributed under the Boost Software License, Version 1.0.
+
+See accompanying file LICENSE_1_0.txt or copy at
+https://www.boost.org/LICENSE_1_0.txt
+////
+
+# Boost.System: Extensible Error Reporting
+Beman Dawes, Christopher Kohlhoff, Peter Dimov
+:toc: left
+:toclevels: 4
+:idprefix:
+:docinfo: private-footer
+:source-highlighter: rouge
+:source-language: c++
+
+:leveloffset: +1
+
+include::system/introduction.adoc[]
+include::system/usage.adoc[]
+include::system/changes.adoc[]
+include::system/rationale.adoc[]
+include::system/reference.adoc[]
+include::system/history.adoc[]
+include::system/acknowledgements.adoc[]
+include::system/copyright.adoc[]
+
+:leveloffset: -1

doc/system/acknowledgements.adoc

@@ -0,0 +1,19 @@
+////
+Copyright 2003-2017 Beman Dawes
+
+Distributed under the Boost Software License, Version 1.0.
+
+See accompanying file LICENSE_1_0.txt or copy at
+http://www.boost.org/LICENSE_1_0.txt
+////
+
+[#acknowledgments]
+# Acknowledgments
+:idprefix: ack_
+
+Christopher Kohlhoff and Peter Dimov made important contributions to the
+design. Comments and suggestions were also received from Pavel Vozenilek,
+Gennaro Prota, Dave Abrahams, Jeff Garland, Iain Hanson, Oliver Kowalke, and
+Oleg Abrosimov. Christopher Kohlhoff suggested several improvements to the
+http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2066.html[N2066]
+paper. Johan Nilsson's comments led to several of the refinements in N2066.

doc/system/changes.adoc

@@ -0,0 +1,133 @@
+////
+Copyright 2018-2022 Peter Dimov
+Distributed under the Boost Software License, Version 1.0.
+https://www.boost.org/LICENSE_1_0.txt
+////
+
+[#changes]
+# Revision History
+:idprefix:
+
+## Changes in Boost 1.80
+
+* When an `error_code` is converted to `std::error_code` and then back
+  to `error_code`, the original is now restored, if possible.
+* Reworked the conversion from `error_category` to `std::error_category`
+  to avoid the one-time allocation that shows up on leak checkers.
+* Added a constructor that allows replacing the source location of an
+  `error_code`, and a corresponding `assign`.
+* Added a converting constructor to `result`.
+
+## Changes in Boost 1.79
+
+* Added a `boost::source_location` parameter to `throw_exception_from_error`.
+* Added `throw_exception_from_error` overloads for `errc::errc_t`,
+  `std::error_code`, `std::errc`, `std::exception_ptr`.
+* `result<T>::value` now automatically supplies `BOOST_CURRENT_LOCATION` to
+  `throw_exception_from_error` via a default argument.
+* Added an `errc::make_error_code` overload taking a source location.
+
+## Changes in Boost 1.78
+
+* Added support for source locations to `error_code`.
+* Added `error_code::to_string`, `error_condition::to_string`, `error_code::what`.
+* `system_error::what()` now contains the source location, if present.
+* Added `result<T, E = error_code>`, a class holding either a value or an
+  error, defined in `<boost/system/result.hpp>`.
+
+## Changes in Boost 1.77
+
+* The conversion operator from `error_category` to `std::error_category`
+  has been improved and no longer requires `<map>` or `<mutex>`.
+* The comparison operators of `error_category` are now inline friends
+  instead of member functions (a side effect of the previous change.)
+* `error_condition` now defers calling `generic_category()` to avoid
+  instantiating the object until it's actually needed.
+* `error_condition::failed` and `error_condition::message` have been
+  undeprecated, and `operator bool()` now once again returns `failed()`.
+* The system category now doesn't call `generic_category()`, to avoid
+  instantiating the object.
+* The return value of `default_error_condition` changes in some cases into
+  an `error_condition` from the generic category, instead of from the system
+  category. This happens on POSIX when the input `error_code` is from
+  the system category and does not correspond to any `errc_t` value.
+* The interoperability of `error_code` and `std::error_code` has been
+  improved substantially. It is now possible to construct
+  `boost::system::error_code` from `std::error_code`, and it's possible
+  to pass `boost::system::error_code` to functions taking `std::error_code&`.
+* A stream insertion operator for `error_condition` has been added.
+
+## Changes in Boost 1.76
+
+* `windows_error.hpp` is no longer deprecated.
+
+## Changes in Boost 1.75
+
+* The platform-specific headers `windows_error.hpp`, `linux_error.hpp`,
+  and `cygwin_error.hpp` emit deprecation messages and are slated for
+  removal.
+* The old names for `generic_category()` and `system_category()` emit
+  deprecation messages and are slated for removal.
+* `error_condition::failed` is deprecated and is slated for removal.
+  `operator bool()` for `error_condition` has been reverted to its old
+  meaning of `value() != 0`. This is done for compatibility with
+  `std::error_condition` as the next release is expected to improve
+  interoperability with `<system_error>` even further. _Note that this
+  does not affect_ `error_code::failed`, which is still alive and well.
+* The overload of `error_condition::message` that takes a buffer is
+  deprecated and is slated for removal, for the same reasons. _Note that
+  this does not affect_ `error_code::message`.
+
+## Changes in Boost 1.74
+
+* `operator bool()` now returns `failed()` instead of `value() != 0`.
+
+## Changes in Boost 1.69
+
+* Boost.System is now header-only. A stub library is still built for
+  compatibility, but linking to it is no longer necessary.
+* Even more functions have been marked `constexpr`.
+* The destructor of `error_category` is now protected and no longer
+  virtual. This is a _potentially breaking change_ but its impact
+  is expected to be limited.
+* `error_category` now has a constructor that accepts a 64 bit identifier,
+  enabling distinct category objects to compare equal.
+* The constructors of `error_category` are now protected.
+* A non-allocating, nonthrowing overload of `message` has been added.
+* A virtual function `failed` has been added, allowing categories for
+  which success is not synonymous with 0.
+* The deprecated `boost::system::throws` object has been removed.
+* `boost::throws()` is now deprecated and its use is discouraged.
+* The constructor of `system_error` taking a single `error_code` argument
+  is now explicit.
+* `system_error::code()` now returns by value.
+
+## Changes in Boost 1.68
+
+On a {cpp}14 compiler, many Boost.System functions and member functions
+are now `constexpr`, and `error_code` and `error_condition` are literal
+classes.
+
+In addition to enabling use in constant expressions (and `constexpr`
+functions), this significantly improves the quality of the generated code.
+
+As a result of this change, however, now using Boost.System from {cpp}14
+or {cpp}17 code requires that the library be also built with {cpp}14 or
+above. This is the default on GCC 6 and newer, but not on GCC 5 or Clang.
+One can build Boost for {cpp}14 by passing the `cxxstd=14` option to `b2`.
+
+(Previous versions allowed code built against any {cpp} standard to link
+with Boost.System built against any {cpp} standard. In 1.68, code using
+any {cpp} standard can link with Boost.System built with {cpp}14 or above,
+but if Boost.System is built with {cpp}11 or below, only code also built
+with {cpp}11 and below can link to it successfully.)
+
+## Changes in Boost 1.65
+
+On a {cpp}11 compiler, Boost.System now provides implicit conversions
+from `boost::system::error_category`, `error_code`, and `error_condition`
+to their standard equivalents from `<system_error>`.
+
+This allows libraries to expose a {cpp}11 interface and report errors
+via `std::error_code` even when using Boost.System, directly or through a
+dependency such as Boost.ASIO.

doc/system/copyright.adoc

@@ -0,0 +1,19 @@
+////
+Copyright 2018-2021 Peter Dimov
+
+Distributed under the Boost Software License, Version 1.0.
+
+See accompanying file LICENSE_1_0.txt or copy at
+http://www.boost.org/LICENSE_1_0.txt
+////
+
+[#copyright]
+# Copyright and License
+:idprefix:
+
+This documentation is
+
+* Copyright 2003-2017 Beman Dawes
+* Copyright 2018-2022 Peter Dimov
+
+and is distributed under the http://www.boost.org/LICENSE_1_0.txt[Boost Software License, Version 1.0].

doc/system/history.adoc

@@ -0,0 +1,30 @@
+////
+Copyright 2003-2017 Beman Dawes
+
+Distributed under the Boost Software License, Version 1.0.
+
+See accompanying file LICENSE_1_0.txt or copy at
+http://www.boost.org/LICENSE_1_0.txt
+////
+
+[#history]
+# History
+:idprefix: history_
+
+http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n1975.html[N1975],
+Filesystem Library Proposal for TR2, accepted for Library Technical
+Report 2 (TR2) at the Berlin meeting, included additional components to
+supplement the Standard Library's Diagnostics clause. Since then, these error
+reporting components have received wider public scrutiny and enhancements have
+been made to the design. The enhanced version has been used by
+http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2006/n2054.pdf[N2054],
+Networking  Library Proposal for TR2, demonstrating that these error reporting
+components are useful beyond the original Filesystem Library.
+
+The original proposal viewed error categories as a binary choice between
+`errno` (i.e. POSIX-style) and the native operating system's error
+codes. The proposed components now allow as many additional error categories as
+are needed by either implementations or by users. The need to support additional
+error categories, for example, occurs in some networking library implementations
+because they are built on top of the POSIX `getaddrinfo` API that
+uses error codes not based on `errno`.

doc/system/introduction.adoc

@@ -0,0 +1,78 @@
+////
+Copyright 2003-2017 Beman Dawes
+Copyright 2018, 2021 Peter Dimov
+
+Distributed under the Boost Software License, Version 1.0.
+
+See accompanying file LICENSE_1_0.txt or copy at
+http://www.boost.org/LICENSE_1_0.txt
+////
+
+[#introduction]
+# Introduction
+:idprefix: intro_
+
+Errors originating from the operating system or other low-level application
+program interfaces (APIs) are typically reported via an integer representing
+an error code, either by returning the code directly from the function (e.g.
+`pthread_mutex_init`) or by using a side channel such as the `errno`
+pseudo-variable under POSIX or `GetLastError()` under Windows.
+
+However, these integer error values can only be interpreted when their source
+is known. The value 5 under Windows means `ERROR_ACCESS_DENIED` when returned
+by `GetLastError()`, but `EIO` when retrieved from `errno`. And conversely,
+the same error condition "access denied" is represented by the value 5 when
+returned by `GetLastError()` and 13 (`EACCES`) when retrieved from `errno`.
+
+This means that in order for code to be able to handle errors from both
+sources (to retrieve a text message describing the error, or to check whether
+the error means "access denied"), it needs to know where the integer error
+value originated. For this to be possible, the integer error value needs to
+be accompanied by a piece of information identifying the source.
+
+Boost.System provides a framework in which this is possible. Errors are
+represented by a class `error_code` which contains both the error value and
+a pointer to their source (called "category"), represented as a class derived
+from `error_category`.
+
+The category provides member functions such as `message`, which returns a text
+message for a specific error value, and `equivalent`, which can be used to test
+whether a specific error value correspond to an error condition such as "access
+denied". `error_code` uses these category-provided functions in the
+implementation of its `message` and `operator==` member functions.
+
+Boost.System contains two predefined category classes, the generic category
+(a reference to which is returned by `generic_category()`) and the system
+category (`system_category()`). The generic category represents the error
+values of the portable subset of `errno` values defined by the POSIX standard,
+whereas the system category is OS dependent. Under POSIX, the system category
+represents the `errno` values returned by the OS APIs (a superset of those in
+the generic category), whereas under Windows, the system category represents
+the error values returned by `GetLastError()`.
+
+The framework is extensible. Users can define their own categories by
+deriving a class from `error_category` and implementing a function that
+returns a reference to an instance of it. This capability is useful both for
+describing library-defined error values, and for adapting existing C API
+libraries that return integer error values.
+
+For those who prefer error reporting via exceptions, Boost.System provides
+a standard exception class `system_error` that stores an `error_code`.
+
+Boost.System was standardized in {cpp}11 as `<system_error>`. For a while,
+the two were equivalent, but Boost.System has evolved since then and now
+contains a number of extensions over its standard sibling:
+
+* A non-allocating overload of `message`;
+* Support for nonzero error codes meaning success, via the `failed` member
+  functions;
+* Support for 64 bit category identifiers, as a solution to the problem
+  that sometimes it's not possible to ensure that only one instance of a
+  category exists in the program;
+* Support for attaching source locations (file/line/function) to error codes;
+* A class `result<T>` that can be used to return either a value or an error
+  code from a function;
+* Various other minor improvements.
+
+`boost::system::error_code` can be converted to, and constructed from,
+`std::error_code`.

doc/system/rationale.adoc

@@ -0,0 +1,27 @@
+////
+Copyright 2003-2017 Beman Dawes
+
+Distributed under the Boost Software License, Version 1.0.
+
+See accompanying file LICENSE_1_0.txt or copy at
+http://www.boost.org/LICENSE_1_0.txt
+////
+
+[#rationale]
+# Design Rationale
+:idprefix: rationale_
+
+`error_code` and `error_condition` are designed as value types so
+they can be copied without slicing and do not require heap allocation, but
+still have polymorphic behavior based on the error category. This is achieved
+by abstract base class `error_category` supplying the polymorphic behavior,
+and `error_code` and `error_condition` containing a pointer to an object of a
+type derived from `error_category`.
+
+Many of the detailed design decisions were driven by the requirements that
+users to be able to add additional error categories, and that it be no more
+difficult to write portable code than system-specific code.
+
+The `operator<<` overload for `error_code` eliminates a misleading conversion to
+`bool` in code like `cout << ec`, where `ec` is of type `error_code`. It is also
+useful in its own right.

include/boost/cerrno.hpp

@@ -7,325 +7,9 @@
 
 //  See library home page at http://www.boost.org/libs/system
 
-#ifndef BOOST_CERRNO_HPP
-#define BOOST_CERRNO_HPP
+#ifndef BOOST_CERRNO_HPP_INCLUDED
+#define BOOST_CERRNO_HPP_INCLUDED
 
-#include <cerrno>
+#include <boost/system/detail/cerrno.hpp>
 
-//  supply errno values likely to be missing, particularly on Windows
-
-#ifndef EAFNOSUPPORT
-#define EAFNOSUPPORT 9901
-#endif
-
-#ifndef EADDRINUSE
-#define EADDRINUSE 9902
-#endif
-
-#ifndef EADDRNOTAVAIL
-#define EADDRNOTAVAIL 9903
-#endif
-
-#ifndef EISCONN
-#define EISCONN 9904
-#endif
-
-#ifndef EBADMSG
-#define EBADMSG 9905
-#endif
-
-#ifndef ECONNABORTED
-#define ECONNABORTED 9906
-#endif
-
-#ifndef EALREADY
-#define EALREADY 9907
-#endif
-
-#ifndef ECONNREFUSED
-#define ECONNREFUSED 9908
-#endif
-
-#ifndef ECONNRESET
-#define ECONNRESET 9909
-#endif
-
-#ifndef EDESTADDRREQ
-#define EDESTADDRREQ 9910
-#endif
-
-#ifndef EHOSTUNREACH
-#define EHOSTUNREACH 9911
-#endif
-
-#ifndef EIDRM
-#define EIDRM 9912
-#endif
-
-#ifndef EMSGSIZE
-#define EMSGSIZE 9913
-#endif
-
-#ifndef ENETDOWN
-#define ENETDOWN 9914
-#endif
-
-#ifndef ENETRESET
-#define ENETRESET 9915
-#endif
-
-#ifndef ENETUNREACH
-#define ENETUNREACH 9916
-#endif
-
-#ifndef ENOBUFS
-#define ENOBUFS 9917
-#endif
-
-#ifndef ENOLINK
-#define ENOLINK 9918
-#endif
-
-#ifndef ENODATA
-#define ENODATA 9919
-#endif
-
-#ifndef ENOMSG
-#define ENOMSG 9920
-#endif
-
-#ifndef ENOPROTOOPT
-#define ENOPROTOOPT 9921
-#endif
-
-#ifndef ENOSR
-#define ENOSR 9922
-#endif
-
-#ifndef ENOTSOCK
-#define ENOTSOCK 9923
-#endif
-
-#ifndef ENOSTR
-#define ENOSTR 9924
-#endif
-
-#ifndef ENOTCONN
-#define ENOTCONN 9925
-#endif
-
-#ifndef ENOTSUP
-#define ENOTSUP 9926
-#endif
-
-#ifndef ECANCELED
-#define ECANCELED 9927
-#endif
-
-#ifndef EINPROGRESS
-#define EINPROGRESS 9928
-#endif
-
-#ifndef EOPNOTSUPP
-#define EOPNOTSUPP 9929
-#endif
-
-#ifndef EWOULDBLOCK
-#define EWOULDBLOCK 9930
-#endif
-
-#ifndef EOWNERDEAD
-#define EOWNERDEAD  9931
-#endif
-
-#ifndef EPROTO
-#define EPROTO 9932
-#endif
-
-#ifndef EPROTONOSUPPORT
-#define EPROTONOSUPPORT 9933
-#endif
-
-#ifndef ENOTRECOVERABLE
-#define ENOTRECOVERABLE 9934
-#endif
-
-#ifndef ETIME
-#define ETIME 9935
-#endif
-
-#ifndef ETXTBSY
-#define ETXTBSY 9936
-#endif
-
-#ifndef ETIMEDOUT
-#define ETIMEDOUT 9938
-#endif
-
-#ifndef ELOOP
-#define ELOOP 9939
-#endif
-
-#ifndef EOVERFLOW
-#define EOVERFLOW 9940
-#endif
-
-#ifndef EPROTOTYPE
-#define EPROTOTYPE 9941
-#endif
-
-#ifndef ENOSYS
-#define ENOSYS 9942
-#endif
-
-#ifndef EINVAL
-#define EINVAL 9943
-#endif
-
-#ifndef ERANGE
-#define ERANGE 9944
-#endif
-
-#ifndef EILSEQ
-#define EILSEQ 9945
-#endif
-
-//  Windows Mobile doesn't appear to define these:
-
-#ifndef E2BIG
-#define E2BIG 9946
-#endif
-
-#ifndef EDOM
-#define EDOM 9947
-#endif
-
-#ifndef EFAULT
-#define EFAULT 9948
-#endif
-
-#ifndef EBADF
-#define EBADF 9949
-#endif
-
-#ifndef EPIPE
-#define EPIPE 9950
-#endif
-
-#ifndef EXDEV
-#define EXDEV 9951
-#endif
-
-#ifndef EBUSY
-#define EBUSY 9952
-#endif
-
-#ifndef ENOTEMPTY
-#define ENOTEMPTY 9953
-#endif
-
-#ifndef ENOEXEC
-#define ENOEXEC 9954
-#endif
-
-#ifndef EEXIST
-#define EEXIST 9955
-#endif
-
-#ifndef EFBIG
-#define EFBIG 9956
-#endif
-
-#ifndef ENAMETOOLONG
-#define ENAMETOOLONG 9957
-#endif
-
-#ifndef ENOTTY
-#define ENOTTY 9958
-#endif
-
-#ifndef EINTR
-#define EINTR 9959
-#endif
-
-#ifndef ESPIPE
-#define ESPIPE 9960
-#endif
-
-#ifndef EIO
-#define EIO 9961
-#endif
-
-#ifndef EISDIR
-#define EISDIR 9962
-#endif
-
-#ifndef ECHILD
-#define ECHILD 9963
-#endif
-
-#ifndef ENOLCK
-#define ENOLCK 9964
-#endif
-
-#ifndef ENOSPC
-#define ENOSPC 9965
-#endif
-
-#ifndef ENXIO
-#define ENXIO 9966
-#endif
-
-#ifndef ENODEV
-#define ENODEV 9967
-#endif
-
-#ifndef ENOENT
-#define ENOENT 9968
-#endif
-
-#ifndef ESRCH
-#define ESRCH 9969
-#endif
-
-#ifndef ENOTDIR
-#define ENOTDIR 9970
-#endif
-
-#ifndef ENOMEM
-#define ENOMEM 9971
-#endif
-
-#ifndef EPERM
-#define EPERM 9972
-#endif
-
-#ifndef EACCES
-#define EACCES 9973
-#endif
-
-#ifndef EROFS
-#define EROFS 9974
-#endif
-
-#ifndef EDEADLK
-#define EDEADLK 9975
-#endif
-
-#ifndef EAGAIN
-#define EAGAIN 9976
-#endif
-
-#ifndef ENFILE
-#define ENFILE 9977
-#endif
-
-#ifndef EMFILE
-#define EMFILE 9978
-#endif
-
-#ifndef EMLINK
-#define EMLINK 9979
-#endif
-
-#endif // include guard
+#endif // #ifndef BOOST_CERRNO_HPP_INCLUDED

include/boost/system.hpp

@@ -0,0 +1,18 @@
+#ifndef BOOST_SYSTEM_HPP_INCLUDED
+#define BOOST_SYSTEM_HPP_INCLUDED
+
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt)
+//
+// See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/error_code.hpp>
+#include <boost/system/system_error.hpp>
+#include <boost/config.hpp>
+
+#if (__cplusplus >= 201103L) && !(defined(BOOST_GCC) && BOOST_GCC < 40800) || (defined(_MSC_VER) && _MSC_VER >= 1900)
+# include <boost/system/result.hpp>
+#endif
+
+#endif // #ifndef BOOST_SYSTEM_HPP_INCLUDED

include/boost/system/api_config.hpp

@@ -0,0 +1,42 @@
+//  boost/system/api_config.hpp  -------------------------------------------------------//
+
+//  Copyright Beman Dawes 2003, 2006, 2010
+
+//  Distributed under the Boost Software License, Version 1.0.
+//  See http://www.boost.org/LICENSE_1_0.txt
+
+//  See http://www.boost.org/libs/system for documentation.
+
+//--------------------------------------------------------------------------------------//
+
+//  Boost.System calls operating system API functions to implement system error category
+//  functions. Usually there is no question as to which API is to be used.
+//
+//  In the case of MinGW or Cygwin/MinGW, however, both POSIX and Windows API's are
+//  available. Chaos ensues if other code thinks one is in use when Boost.System was
+//  actually built with the other. This header centralizes the API choice and prevents
+//  user definition of API macros, thus elminating the possibility of mismatches and the
+//  need to test configurations with little or no practical value.
+//
+
+//--------------------------------------------------------------------------------------//
+
+#ifndef BOOST_SYSTEM_API_CONFIG_HPP                  
+#define BOOST_SYSTEM_API_CONFIG_HPP
+
+# if defined(BOOST_POSIX_API) || defined(BOOST_WINDOWS_API)
+#   error user defined BOOST_POSIX_API or BOOST_WINDOWS_API not supported
+# endif
+
+//  BOOST_POSIX_API or BOOST_WINDOWS_API specify which API to use
+//    Cygwin/MinGW does not predefine _WIN32.
+//    Standalone MinGW and all other known Windows compilers do predefine _WIN32
+//    Compilers that predefine _WIN32 or __MINGW32__ do so for Windows 64-bit builds too.
+
+# if defined(_WIN32) || defined(__CYGWIN__) // Windows default, including MinGW and Cygwin
+#   define BOOST_WINDOWS_API
+# else
+#   define BOOST_POSIX_API 
+# endif
+                                     
+#endif  // BOOST_SYSTEM_API_CONFIG_HPP 

include/boost/system/config.hpp

@@ -1,4 +1,4 @@
-//  boost/system/config.hpp  -------------------------------------------------//
+//  boost/system/config.hpp  -----------------------------------------------------------//
 
 //  Copyright Beman Dawes 2003, 2006
 
@@ -7,69 +7,44 @@
 
 //  See http://www.boost.org/libs/system for documentation.
 
-#ifndef BOOST_SYSTEM_CONFIG_HPP                  
+#ifndef BOOST_SYSTEM_CONFIG_HPP
 #define BOOST_SYSTEM_CONFIG_HPP
 
 #include <boost/config.hpp>
+#include <boost/system/api_config.hpp>  // for BOOST_POSIX_API or BOOST_WINDOWS_API
 
-//  BOOST_POSIX_API or BOOST_WINDOWS_API specify which API to use.
-//  If not specified, a sensible default will be applied.
+// This header implemented separate compilation features as described in
+// http://www.boost.org/more/separate_compilation.html
+//
+// It's only retained for compatibility now that the library is header-only.
 
-# if defined( BOOST_WINDOWS_API ) && defined( BOOST_POSIX_API )
-#   error both BOOST_WINDOWS_API and BOOST_POSIX_API are defined
-# elif !defined( BOOST_WINDOWS_API ) && !defined( BOOST_POSIX_API )
-#   if defined(_WIN32) || defined(__WIN32__) || defined(WIN32) || defined(__CYGWIN__)
-#     define BOOST_WINDOWS_API
-#   else
-#     define BOOST_POSIX_API 
-#   endif
+//  normalize macros  ------------------------------------------------------------------//
+
+#if !defined(BOOST_SYSTEM_DYN_LINK) && !defined(BOOST_SYSTEM_STATIC_LINK) \
+  && !defined(BOOST_ALL_DYN_LINK) && !defined(BOOST_ALL_STATIC_LINK)
+# define BOOST_SYSTEM_STATIC_LINK
+#endif
+
+#if defined(BOOST_ALL_DYN_LINK) && !defined(BOOST_SYSTEM_DYN_LINK)
+# define BOOST_SYSTEM_DYN_LINK 
+#elif defined(BOOST_ALL_STATIC_LINK) && !defined(BOOST_SYSTEM_STATIC_LINK)
+# define BOOST_SYSTEM_STATIC_LINK 
+#endif
+
+#if defined(BOOST_SYSTEM_DYN_LINK) && defined(BOOST_SYSTEM_STATIC_LINK)
+# error Must not define both BOOST_SYSTEM_DYN_LINK and BOOST_SYSTEM_STATIC_LINK
+#endif
+
+//  enable dynamic or static linking as requested --------------------------------------//
+
+#if defined(BOOST_ALL_DYN_LINK) || defined(BOOST_SYSTEM_DYN_LINK)
+# if defined(BOOST_SYSTEM_SOURCE)
+#   define BOOST_SYSTEM_DECL BOOST_SYMBOL_EXPORT
+# else 
+#   define BOOST_SYSTEM_DECL BOOST_SYMBOL_IMPORT
 # endif
-
-//  enable dynamic linking on Windows  ---------------------------------------//
-
-//#  if (defined(BOOST_ALL_DYN_LINK) || defined(BOOST_SYSTEM_DYN_LINK)) && defined(__BORLANDC__) && defined(__WIN32__)
-//#    error Dynamic linking Boost.System does not work for Borland; use static linking instead
-//#  endif
-
-#ifdef BOOST_HAS_DECLSPEC // defined in config system
-// we need to import/export our code only if the user has specifically
-// asked for it by defining either BOOST_ALL_DYN_LINK if they want all boost
-// libraries to be dynamically linked, or BOOST_SYSTEM_DYN_LINK
-// if they want just this one to be dynamically liked:
-#if defined(BOOST_ALL_DYN_LINK) || defined(BOOST_SYSTEM_DYN_LINK)
-// export if this is our own source, otherwise import:
-#ifdef BOOST_SYSTEM_SOURCE
-# define BOOST_SYSTEM_DECL __declspec(dllexport)
 #else
-# define BOOST_SYSTEM_DECL __declspec(dllimport)
-#endif  // BOOST_SYSTEM_SOURCE
-#endif  // DYN_LINK
-#endif  // BOOST_HAS_DECLSPEC
-//
-// if BOOST_SYSTEM_DECL isn't defined yet define it now:
-#ifndef BOOST_SYSTEM_DECL
-#define BOOST_SYSTEM_DECL
+# define BOOST_SYSTEM_DECL
 #endif
 
-//  enable automatic library variant selection  ------------------------------// 
-
-#if !defined(BOOST_SYSTEM_SOURCE) && !defined(BOOST_ALL_NO_LIB) && !defined(BOOST_SYSTEM_NO_LIB)
-//
-// Set the name of our library, this will get undef'ed by auto_link.hpp
-// once it's done with it:
-//
-#define BOOST_LIB_NAME boost_system
-//
-// If we're importing code from a dll, then tell auto_link.hpp about it:
-//
-#if defined(BOOST_ALL_DYN_LINK) || defined(BOOST_SYSTEM_DYN_LINK)
-#  define BOOST_DYN_LINK
-#endif
-//
-// And include the header that does the work:
-//
-#include <boost/config/auto_link.hpp>
-#endif  // auto-linking disabled
-
 #endif // BOOST_SYSTEM_CONFIG_HPP
-

include/boost/system/cygwin_error.hpp

@@ -7,8 +7,15 @@
 
 //  See library home page at http://www.boost.org/libs/system
 
-#ifndef BOOST_CYGWIN_ERROR_HPP
-#define BOOST_CYGWIN_ERROR_HPP
+#ifndef BOOST_SYSTEM_CYGWIN_ERROR_HPP
+#define BOOST_SYSTEM_CYGWIN_ERROR_HPP
+
+#include <boost/config/pragma_message.hpp>
+
+#if !defined(BOOST_ALLOW_DEPRECATED_HEADERS)
+  BOOST_PRAGMA_MESSAGE("This header is deprecated and is slated for removal."
+  " If you want it retained, please open an issue in github.com/boostorg/system.")
+#endif
 
 //  This header is effectively empty for compiles on operating systems where
 //  it is not applicable.
@@ -23,7 +30,7 @@ namespace boost
   {
     //  To construct an error_code after a API error:
     //
-    //      error_code( errno, system_category )
+    //      error_code( errno, system_category() )
 
     //  User code should use the portable "posix" enums for POSIX errors; this
     //  allows such code to be portable to non-POSIX systems. For the non-POSIX
@@ -46,11 +53,11 @@ namespace boost
     namespace cygwin_error
     {
       inline error_code make_error_code( cygwin_errno e )
-        { return error_code( e, get_system_category() ); }
+        { return error_code( e, system_category() ); }
     }
   }
 }
 
 #endif  // __CYGWIN__
 
-#endif  // BOOST_CYGWIN_ERROR_HPP
+#endif  // BOOST_SYSTEM_CYGWIN_ERROR_HPP

include/boost/system/detail/append_int.hpp

@@ -0,0 +1,32 @@
+#ifndef BOOST_SYSTEM_DETAIL_APPEND_INT_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_APPEND_INT_HPP_INCLUDED
+
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt)
+
+#include <boost/system/detail/snprintf.hpp>
+#include <string>
+
+//
+
+namespace boost
+{
+namespace system
+{
+namespace detail
+{
+
+inline void append_int( std::string& s, int v )
+{
+    char buffer[ 32 ];
+    detail::snprintf( buffer, sizeof( buffer ), ":%d", v );
+
+    s += buffer;
+}
+
+} // namespace detail
+} // namespace system
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_APPEND_INT_HPP_INCLUDED

include/boost/system/detail/cerrno.hpp

@@ -0,0 +1,329 @@
+//  Copyright Beman Dawes 2005.
+//  Use, modification, and distribution is subject to the Boost Software
+//  License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+
+//  See library home page at http://www.boost.org/libs/system
+
+#ifndef BOOST_SYSTEM_DETAIL_CERRNO_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_CERRNO_HPP_INCLUDED
+
+#include <cerrno>
+
+//  supply errno values likely to be missing, particularly on Windows
+
+#ifndef EAFNOSUPPORT
+#define EAFNOSUPPORT 9901
+#endif
+
+#ifndef EADDRINUSE
+#define EADDRINUSE 9902
+#endif
+
+#ifndef EADDRNOTAVAIL
+#define EADDRNOTAVAIL 9903
+#endif
+
+#ifndef EISCONN
+#define EISCONN 9904
+#endif
+
+#ifndef EBADMSG
+#define EBADMSG 9905
+#endif
+
+#ifndef ECONNABORTED
+#define ECONNABORTED 9906
+#endif
+
+#ifndef EALREADY
+#define EALREADY 9907
+#endif
+
+#ifndef ECONNREFUSED
+#define ECONNREFUSED 9908
+#endif
+
+#ifndef ECONNRESET
+#define ECONNRESET 9909
+#endif
+
+#ifndef EDESTADDRREQ
+#define EDESTADDRREQ 9910
+#endif
+
+#ifndef EHOSTUNREACH
+#define EHOSTUNREACH 9911
+#endif
+
+#ifndef EIDRM
+#define EIDRM 9912
+#endif
+
+#ifndef EMSGSIZE
+#define EMSGSIZE 9913
+#endif
+
+#ifndef ENETDOWN
+#define ENETDOWN 9914
+#endif
+
+#ifndef ENETRESET
+#define ENETRESET 9915
+#endif
+
+#ifndef ENETUNREACH
+#define ENETUNREACH 9916
+#endif
+
+#ifndef ENOBUFS
+#define ENOBUFS 9917
+#endif
+
+#ifndef ENOLINK
+#define ENOLINK 9918
+#endif
+
+#ifndef ENODATA
+#define ENODATA 9919
+#endif
+
+#ifndef ENOMSG
+#define ENOMSG 9920
+#endif
+
+#ifndef ENOPROTOOPT
+#define ENOPROTOOPT 9921
+#endif
+
+#ifndef ENOSR
+#define ENOSR 9922
+#endif
+
+#ifndef ENOTSOCK
+#define ENOTSOCK 9923
+#endif
+
+#ifndef ENOSTR
+#define ENOSTR 9924
+#endif
+
+#ifndef ENOTCONN
+#define ENOTCONN 9925
+#endif
+
+#ifndef ENOTSUP
+#define ENOTSUP 9926
+#endif
+
+#ifndef ECANCELED
+#define ECANCELED 9927
+#endif
+
+#ifndef EINPROGRESS
+#define EINPROGRESS 9928
+#endif
+
+#ifndef EOPNOTSUPP
+#define EOPNOTSUPP 9929
+#endif
+
+#ifndef EWOULDBLOCK
+#define EWOULDBLOCK 9930
+#endif
+
+#ifndef EOWNERDEAD
+#define EOWNERDEAD  9931
+#endif
+
+#ifndef EPROTO
+#define EPROTO 9932
+#endif
+
+#ifndef EPROTONOSUPPORT
+#define EPROTONOSUPPORT 9933
+#endif
+
+#ifndef ENOTRECOVERABLE
+#define ENOTRECOVERABLE 9934
+#endif
+
+#ifndef ETIME
+#define ETIME 9935
+#endif
+
+#ifndef ETXTBSY
+#define ETXTBSY 9936
+#endif
+
+#ifndef ETIMEDOUT
+#define ETIMEDOUT 9938
+#endif
+
+#ifndef ELOOP
+#define ELOOP 9939
+#endif
+
+#ifndef EOVERFLOW
+#define EOVERFLOW 9940
+#endif
+
+#ifndef EPROTOTYPE
+#define EPROTOTYPE 9941
+#endif
+
+#ifndef ENOSYS
+#define ENOSYS 9942
+#endif
+
+#ifndef EINVAL
+#define EINVAL 9943
+#endif
+
+#ifndef ERANGE
+#define ERANGE 9944
+#endif
+
+#ifndef EILSEQ
+#define EILSEQ 9945
+#endif
+
+//  Windows Mobile doesn't appear to define these:
+
+#ifndef E2BIG
+#define E2BIG 9946
+#endif
+
+#ifndef EDOM
+#define EDOM 9947
+#endif
+
+#ifndef EFAULT
+#define EFAULT 9948
+#endif
+
+#ifndef EBADF
+#define EBADF 9949
+#endif
+
+#ifndef EPIPE
+#define EPIPE 9950
+#endif
+
+#ifndef EXDEV
+#define EXDEV 9951
+#endif
+
+#ifndef EBUSY
+#define EBUSY 9952
+#endif
+
+#ifndef ENOTEMPTY
+#define ENOTEMPTY 9953
+#endif
+
+#ifndef ENOEXEC
+#define ENOEXEC 9954
+#endif
+
+#ifndef EEXIST
+#define EEXIST 9955
+#endif
+
+#ifndef EFBIG
+#define EFBIG 9956
+#endif
+
+#ifndef ENAMETOOLONG
+#define ENAMETOOLONG 9957
+#endif
+
+#ifndef ENOTTY
+#define ENOTTY 9958
+#endif
+
+#ifndef EINTR
+#define EINTR 9959
+#endif
+
+#ifndef ESPIPE
+#define ESPIPE 9960
+#endif
+
+#ifndef EIO
+#define EIO 9961
+#endif
+
+#ifndef EISDIR
+#define EISDIR 9962
+#endif
+
+#ifndef ECHILD
+#define ECHILD 9963
+#endif
+
+#ifndef ENOLCK
+#define ENOLCK 9964
+#endif
+
+#ifndef ENOSPC
+#define ENOSPC 9965
+#endif
+
+#ifndef ENXIO
+#define ENXIO 9966
+#endif
+
+#ifndef ENODEV
+#define ENODEV 9967
+#endif
+
+#ifndef ENOENT
+#define ENOENT 9968
+#endif
+
+#ifndef ESRCH
+#define ESRCH 9969
+#endif
+
+#ifndef ENOTDIR
+#define ENOTDIR 9970
+#endif
+
+#ifndef ENOMEM
+#define ENOMEM 9971
+#endif
+
+#ifndef EPERM
+#define EPERM 9972
+#endif
+
+#ifndef EACCES
+#define EACCES 9973
+#endif
+
+#ifndef EROFS
+#define EROFS 9974
+#endif
+
+#ifndef EDEADLK
+#define EDEADLK 9975
+#endif
+
+#ifndef EAGAIN
+#define EAGAIN 9976
+#endif
+
+#ifndef ENFILE
+#define ENFILE 9977
+#endif
+
+#ifndef EMFILE
+#define EMFILE 9978
+#endif
+
+#ifndef EMLINK
+#define EMLINK 9979
+#endif
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_CERRNO_HPP_INCLUDED

include/boost/system/detail/config.hpp

@@ -0,0 +1,81 @@
+#ifndef BOOST_SYSTEM_DETAIL_CONFIG_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_CONFIG_HPP_INCLUDED
+
+// Copyright 2018-2022 Peter Dimov
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// See http://www.boost.org/libs/system for documentation.
+
+#include <boost/config.hpp>
+#include <boost/config/workaround.hpp>
+
+// BOOST_SYSTEM_HAS_SYSTEM_ERROR
+
+#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR) && !defined(BOOST_NO_CXX11_HDR_ATOMIC) && !defined(BOOST_NO_CXX11_HDR_MUTEX)
+# define BOOST_SYSTEM_HAS_SYSTEM_ERROR
+#endif
+
+// BOOST_SYSTEM_NOEXCEPT
+// Retained for backward compatibility
+
+#define BOOST_SYSTEM_NOEXCEPT BOOST_NOEXCEPT
+
+// BOOST_SYSTEM_HAS_CONSTEXPR
+
+#if !defined(BOOST_NO_CXX14_CONSTEXPR)
+# define BOOST_SYSTEM_HAS_CONSTEXPR
+#endif
+
+#if BOOST_WORKAROUND(BOOST_GCC, < 60000)
+# undef BOOST_SYSTEM_HAS_CONSTEXPR
+#endif
+
+#if defined(BOOST_SYSTEM_HAS_CONSTEXPR)
+# define BOOST_SYSTEM_CONSTEXPR constexpr
+#else
+# define BOOST_SYSTEM_CONSTEXPR
+#endif
+
+// BOOST_SYSTEM_DEPRECATED
+
+#if defined(__clang__)
+# define BOOST_SYSTEM_DEPRECATED(msg) __attribute__((deprecated(msg)))
+#elif defined(__GNUC__)
+# if __GNUC__ * 100 + __GNUC_MINOR__ >= 405
+#  define BOOST_SYSTEM_DEPRECATED(msg) __attribute__((deprecated(msg)))
+# else
+#  define BOOST_SYSTEM_DEPRECATED(msg) __attribute__((deprecated))
+# endif
+#elif defined(_MSC_VER)
+#  define BOOST_SYSTEM_DEPRECATED(msg) __declspec(deprecated(msg))
+#elif defined(__sun)
+#  define BOOST_SYSTEM_DEPRECATED(msg) __attribute__((deprecated(msg)))
+#else
+# define BOOST_SYSTEM_DEPRECATED(msg)
+#endif
+
+// BOOST_SYSTEM_CLANG_6
+
+#if defined(__clang__) && (__clang_major__ < 7 || (defined(__APPLE__) && __clang_major__ < 11))
+# define BOOST_SYSTEM_CLANG_6
+#endif
+
+//
+
+#if defined(BOOST_LIBSTDCXX_VERSION) && BOOST_LIBSTDCXX_VERSION < 50000
+# define BOOST_SYSTEM_AVOID_STD_GENERIC_CATEGORY
+#endif
+
+#if defined(__CYGWIN__) || defined(__MINGW32__) || (defined(_MSC_VER) && _MSC_VER == 1800) || (defined(BOOST_LIBSTDCXX_VERSION) && BOOST_LIBSTDCXX_VERSION < 90000)
+
+// Under Cygwin (and MinGW!), std::system_category() is POSIX
+// Under VS2013, std::system_category() isn't quite right
+// Under libstdc++ before 7.4, before 8.3, before 9.1, default_error_condition
+// for the system category returns a condition from the system category
+
+# define BOOST_SYSTEM_AVOID_STD_SYSTEM_CATEGORY
+#endif
+
+#endif // BOOST_SYSTEM_DETAIL_CONFIG_HPP_INCLUDED

include/boost/system/detail/enable_if.hpp

@@ -0,0 +1,32 @@
+#ifndef BOOST_SYSTEM_DETAIL_ENABLE_IF_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_ENABLE_IF_HPP_INCLUDED
+
+// Copyright 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0
+// http://www.boost.org/LICENSE_1_0.txt
+
+namespace boost
+{
+
+namespace system
+{
+
+namespace detail
+{
+
+template<bool C, class T = void> struct enable_if
+{
+    typedef T type;
+};
+
+template<class T> struct enable_if<false, T>
+{
+};
+
+} // namespace detail
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_ENABLE_IF_HPP_INCLUDED

include/boost/system/detail/errc.hpp

@@ -0,0 +1,126 @@
+#ifndef BOOST_SYSTEM_DETAIL_ERRC_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_ERRC_HPP_INCLUDED
+
+// Copyright Beman Dawes 2006, 2007
+// Copyright Christoper Kohlhoff 2007
+// Copyright Peter Dimov 2017, 2018, 2020
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/is_error_condition_enum.hpp>
+#include <boost/system/detail/cerrno.hpp>
+
+namespace boost
+{
+
+namespace system
+{
+
+namespace errc
+{
+
+enum errc_t
+{
+    success = 0,
+    address_family_not_supported = EAFNOSUPPORT,
+    address_in_use = EADDRINUSE,
+    address_not_available = EADDRNOTAVAIL,
+    already_connected = EISCONN,
+    argument_list_too_long = E2BIG,
+    argument_out_of_domain = EDOM,
+    bad_address = EFAULT,
+    bad_file_descriptor = EBADF,
+    bad_message = EBADMSG,
+    broken_pipe = EPIPE,
+    connection_aborted = ECONNABORTED,
+    connection_already_in_progress = EALREADY,
+    connection_refused = ECONNREFUSED,
+    connection_reset = ECONNRESET,
+    cross_device_link = EXDEV,
+    destination_address_required = EDESTADDRREQ,
+    device_or_resource_busy = EBUSY,
+    directory_not_empty = ENOTEMPTY,
+    executable_format_error = ENOEXEC,
+    file_exists = EEXIST,
+    file_too_large = EFBIG,
+    filename_too_long = ENAMETOOLONG,
+    function_not_supported = ENOSYS,
+    host_unreachable = EHOSTUNREACH,
+    identifier_removed = EIDRM,
+    illegal_byte_sequence = EILSEQ,
+    inappropriate_io_control_operation = ENOTTY,
+    interrupted = EINTR,
+    invalid_argument = EINVAL,
+    invalid_seek = ESPIPE,
+    io_error = EIO,
+    is_a_directory = EISDIR,
+    message_size = EMSGSIZE,
+    network_down = ENETDOWN,
+    network_reset = ENETRESET,
+    network_unreachable = ENETUNREACH,
+    no_buffer_space = ENOBUFS,
+    no_child_process = ECHILD,
+    no_link = ENOLINK,
+    no_lock_available = ENOLCK,
+    no_message_available = ENODATA,
+    no_message = ENOMSG,
+    no_protocol_option = ENOPROTOOPT,
+    no_space_on_device = ENOSPC,
+    no_stream_resources = ENOSR,
+    no_such_device_or_address = ENXIO,
+    no_such_device = ENODEV,
+    no_such_file_or_directory = ENOENT,
+    no_such_process = ESRCH,
+    not_a_directory = ENOTDIR,
+    not_a_socket = ENOTSOCK,
+    not_a_stream = ENOSTR,
+    not_connected = ENOTCONN,
+    not_enough_memory = ENOMEM,
+    not_supported = ENOTSUP,
+    operation_canceled = ECANCELED,
+    operation_in_progress = EINPROGRESS,
+    operation_not_permitted = EPERM,
+    operation_not_supported = EOPNOTSUPP,
+    operation_would_block = EWOULDBLOCK,
+    owner_dead = EOWNERDEAD,
+    permission_denied = EACCES,
+    protocol_error = EPROTO,
+    protocol_not_supported = EPROTONOSUPPORT,
+    read_only_file_system = EROFS,
+    resource_deadlock_would_occur = EDEADLK,
+    resource_unavailable_try_again = EAGAIN,
+    result_out_of_range = ERANGE,
+    state_not_recoverable = ENOTRECOVERABLE,
+    stream_timeout = ETIME,
+    text_file_busy = ETXTBSY,
+    timed_out = ETIMEDOUT,
+    too_many_files_open_in_system = ENFILE,
+    too_many_files_open = EMFILE,
+    too_many_links = EMLINK,
+    too_many_symbolic_link_levels = ELOOP,
+    value_too_large = EOVERFLOW,
+    wrong_protocol_type = EPROTOTYPE
+};
+
+} // namespace errc
+
+#ifdef BOOST_SYSTEM_ENABLE_DEPRECATED
+
+namespace posix = errc;
+namespace posix_error = errc;
+
+#endif
+
+template<> struct is_error_condition_enum<errc::errc_t>
+{
+    static const bool value = true;
+};
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_ERRC_HPP_INCLUDED

include/boost/system/detail/error_category.hpp

@@ -0,0 +1,219 @@
+#ifndef BOOST_SYSTEM_DETAIL_ERROR_CATEGORY_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_ERROR_CATEGORY_HPP_INCLUDED
+
+//  Copyright Beman Dawes 2006, 2007
+//  Copyright Christoper Kohlhoff 2007
+//  Copyright Peter Dimov 2017, 2018
+//
+//  Distributed under the Boost Software License, Version 1.0. (See accompanying
+//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+//  See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/config.hpp>
+#include <boost/cstdint.hpp>
+#include <boost/config.hpp>
+#include <string>
+#include <functional>
+#include <cstddef>
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+# include <system_error>
+# include <atomic>
+#endif
+
+namespace boost
+{
+
+namespace system
+{
+
+class error_category;
+class error_code;
+class error_condition;
+
+std::size_t hash_value( error_code const & ec );
+
+namespace detail
+{
+
+BOOST_SYSTEM_CONSTEXPR bool failed_impl( int ev, error_category const & cat );
+
+class std_category;
+
+} // namespace detail
+
+#if ( defined( BOOST_GCC ) && BOOST_GCC >= 40600 ) || defined( BOOST_CLANG )
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
+#endif
+
+#if defined(BOOST_MSVC)
+#pragma warning(push)
+#pragma warning(disable: 4351) //  new behavior: elements of array will be default initialized
+#endif
+
+class BOOST_SYMBOL_VISIBLE error_category
+{
+private:
+
+    friend std::size_t hash_value( error_code const & ec );
+    friend BOOST_SYSTEM_CONSTEXPR bool detail::failed_impl( int ev, error_category const & cat );
+
+    friend class error_code;
+    friend class error_condition;
+
+#if !defined(BOOST_NO_CXX11_DELETED_FUNCTIONS)
+public:
+
+    error_category( error_category const & ) = delete;
+    error_category& operator=( error_category const & ) = delete;
+
+#else
+private:
+
+    error_category( error_category const & );
+    error_category& operator=( error_category const & );
+
+#endif
+
+private:
+
+    boost::ulong_long_type id_;
+
+    static std::size_t const stdcat_size_ = 4 * sizeof( void const* );
+
+    union
+    {
+        mutable unsigned char stdcat_[ stdcat_size_ ];
+        void const* stdcat_align_;
+    };
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    mutable std::atomic< unsigned > sc_init_;
+
+#else
+
+    unsigned sc_init_;
+
+#endif
+
+protected:
+
+#if !defined(BOOST_NO_CXX11_DEFAULTED_FUNCTIONS) && !defined(BOOST_NO_CXX11_NON_PUBLIC_DEFAULTED_FUNCTIONS)
+
+    ~error_category() = default;
+
+#else
+
+    // We'd like to make the destructor protected, to make code that deletes
+    // an error_category* not compile; unfortunately, doing the below makes
+    // the destructor user-provided and hence breaks use after main, as the
+    // categories may get destroyed before code that uses them
+
+    // ~error_category() {}
+
+#endif
+
+    BOOST_SYSTEM_CONSTEXPR error_category() BOOST_NOEXCEPT: id_( 0 ), stdcat_(), sc_init_()
+    {
+    }
+
+    explicit BOOST_SYSTEM_CONSTEXPR error_category( boost::ulong_long_type id ) BOOST_NOEXCEPT: id_( id ), stdcat_(), sc_init_()
+    {
+    }
+
+public:
+
+    virtual const char * name() const BOOST_NOEXCEPT = 0;
+
+    virtual error_condition default_error_condition( int ev ) const BOOST_NOEXCEPT;
+    virtual bool equivalent( int code, const error_condition & condition ) const BOOST_NOEXCEPT;
+    virtual bool equivalent( const error_code & code, int condition ) const BOOST_NOEXCEPT;
+
+    virtual std::string message( int ev ) const = 0;
+    virtual char const * message( int ev, char * buffer, std::size_t len ) const BOOST_NOEXCEPT;
+
+    virtual bool failed( int ev ) const BOOST_NOEXCEPT
+    {
+        return ev != 0;
+    }
+
+    friend BOOST_SYSTEM_CONSTEXPR bool operator==( error_category const & lhs, error_category const & rhs ) BOOST_NOEXCEPT
+    {
+        return rhs.id_ == 0? &lhs == &rhs: lhs.id_ == rhs.id_;
+    }
+
+    friend BOOST_SYSTEM_CONSTEXPR bool operator!=( error_category const & lhs, error_category const & rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+    friend BOOST_SYSTEM_CONSTEXPR bool operator<( error_category const & lhs, error_category const & rhs ) BOOST_NOEXCEPT
+    {
+        if( lhs.id_ < rhs.id_ )
+        {
+            return true;
+        }
+
+        if( lhs.id_ > rhs.id_ )
+        {
+            return false;
+        }
+
+        if( rhs.id_ != 0 )
+        {
+            return false; // equal
+        }
+
+        return std::less<error_category const *>()( &lhs, &rhs );
+    }
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    void init_stdcat() const;
+
+# if defined(__SUNPRO_CC) // trailing __global is not supported
+    operator std::error_category const & () const;
+# else
+    operator std::error_category const & () const BOOST_SYMBOL_VISIBLE;
+# endif
+
+#endif
+};
+
+#if defined(BOOST_MSVC)
+#pragma warning(pop)
+#endif
+
+#if ( defined( BOOST_GCC ) && BOOST_GCC >= 40600 ) || defined( BOOST_CLANG )
+#pragma GCC diagnostic pop
+#endif
+
+namespace detail
+{
+
+static const boost::ulong_long_type generic_category_id = ( boost::ulong_long_type( 0xB2AB117A ) << 32 ) + 0x257EDFD0;
+static const boost::ulong_long_type system_category_id = generic_category_id + 1;
+static const boost::ulong_long_type interop_category_id = generic_category_id + 2;
+
+BOOST_SYSTEM_CONSTEXPR inline bool failed_impl( int ev, error_category const & cat )
+{
+    if( cat.id_ == system_category_id || cat.id_ == generic_category_id )
+    {
+        return ev != 0;
+    }
+    else
+    {
+        return cat.failed( ev );
+    }
+}
+
+} // namespace detail
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_ERROR_CATEGORY_HPP_INCLUDED

include/boost/system/detail/error_category_impl.hpp

@@ -0,0 +1,196 @@
+#ifndef BOOST_SYSTEM_DETAIL_ERROR_CATEGORY_IMPL_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_ERROR_CATEGORY_IMPL_HPP_INCLUDED
+
+//  Copyright Beman Dawes 2006, 2007
+//  Copyright Christoper Kohlhoff 2007
+//  Copyright Peter Dimov 2017, 2018
+//
+//  Distributed under the Boost Software License, Version 1.0. (See accompanying
+//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+//  See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/error_category.hpp>
+#include <boost/system/detail/error_condition.hpp>
+#include <boost/system/detail/error_code.hpp>
+#include <boost/system/detail/snprintf.hpp>
+#include <boost/system/detail/config.hpp>
+#include <boost/config.hpp>
+#include <string>
+#include <cstring>
+
+namespace boost
+{
+namespace system
+{
+
+// error_category default implementation
+
+inline error_condition error_category::default_error_condition( int ev ) const BOOST_NOEXCEPT
+{
+    return error_condition( ev, *this );
+}
+
+inline bool error_category::equivalent( int code, const error_condition & condition ) const BOOST_NOEXCEPT
+{
+    return default_error_condition( code ) == condition;
+}
+
+inline bool error_category::equivalent( const error_code & code, int condition ) const BOOST_NOEXCEPT
+{
+    return code.equals( condition, *this );
+}
+
+inline char const * error_category::message( int ev, char * buffer, std::size_t len ) const BOOST_NOEXCEPT
+{
+    if( len == 0 )
+    {
+        return buffer;
+    }
+
+    if( len == 1 )
+    {
+        buffer[0] = 0;
+        return buffer;
+    }
+
+#if !defined(BOOST_NO_EXCEPTIONS)
+    try
+#endif
+    {
+        std::string m = this->message( ev );
+
+# if defined( BOOST_MSVC )
+#  pragma warning( push )
+#  pragma warning( disable: 4996 )
+# elif defined(__clang__) && defined(__has_warning)
+#  pragma clang diagnostic push
+#  if __has_warning("-Wdeprecated-declarations")
+#   pragma clang diagnostic ignored "-Wdeprecated-declarations"
+#  endif
+# endif
+
+        std::strncpy( buffer, m.c_str(), len - 1 );
+        buffer[ len-1 ] = 0;
+
+# if defined( BOOST_MSVC )
+#  pragma warning( pop )
+# elif defined(__clang__) && defined(__has_warning)
+#  pragma clang diagnostic pop
+# endif
+
+        return buffer;
+    }
+#if !defined(BOOST_NO_EXCEPTIONS)
+    catch( ... )
+    {
+        detail::snprintf( buffer, len, "No message text available for error %d", ev );
+        return buffer;
+    }
+#endif
+}
+
+} // namespace system
+} // namespace boost
+
+// interoperability with std::error_code, std::error_condition
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+#include <boost/system/detail/std_category_impl.hpp>
+#include <mutex>
+#include <new>
+
+namespace boost
+{
+namespace system
+{
+
+namespace detail
+{
+
+template<class = void> struct stdcat_mx_holder
+{
+    static std::mutex mx_;
+};
+
+template<class T> std::mutex stdcat_mx_holder<T>::mx_;
+
+} // namespace detail
+
+inline void error_category::init_stdcat() const
+{
+    static_assert( sizeof( stdcat_ ) >= sizeof( boost::system::detail::std_category ), "sizeof(stdcat_) is not enough for std_category" );
+
+#if defined(BOOST_MSVC) && BOOST_MSVC < 1900
+    // no alignof
+#else
+
+    static_assert( alignof( decltype(stdcat_align_) ) >= alignof( boost::system::detail::std_category ), "alignof(stdcat_) is not enough for std_category" );
+
+#endif
+
+    std::lock_guard<std::mutex> lk( boost::system::detail::stdcat_mx_holder<>::mx_ );
+
+    if( sc_init_.load( std::memory_order_acquire ) == 0 )
+    {
+        ::new( static_cast<void*>( stdcat_ ) ) boost::system::detail::std_category( this, 0 );
+        sc_init_.store( 1, std::memory_order_release );
+    }
+}
+
+#if defined( BOOST_GCC ) && BOOST_GCC >= 40800 && BOOST_GCC < 70000
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wstrict-aliasing"
+#endif
+
+inline BOOST_NOINLINE error_category::operator std::error_category const & () const
+{
+    if( id_ == detail::generic_category_id )
+    {
+// This condition must be the same as the one in error_condition.hpp
+#if defined(BOOST_SYSTEM_AVOID_STD_GENERIC_CATEGORY)
+
+        static const boost::system::detail::std_category generic_instance( this, 0x1F4D3 );
+        return generic_instance;
+
+#else
+
+        return std::generic_category();
+
+#endif
+    }
+
+    if( id_ == detail::system_category_id )
+    {
+// This condition must be the same as the one in error_code.hpp
+#if defined(BOOST_SYSTEM_AVOID_STD_SYSTEM_CATEGORY)
+
+        static const boost::system::detail::std_category system_instance( this, 0x1F4D7 );
+        return system_instance;
+
+#else
+
+        return std::system_category();
+
+#endif
+    }
+
+    if( sc_init_.load( std::memory_order_acquire ) == 0 )
+    {
+        init_stdcat();
+    }
+
+    return *static_cast<boost::system::detail::std_category const*>( static_cast<void const*>( stdcat_ ) );
+}
+
+#if defined( BOOST_GCC ) && BOOST_GCC >= 40800 && BOOST_GCC < 70000
+#pragma GCC diagnostic pop
+#endif
+
+} // namespace system
+} // namespace boost
+
+#endif // #if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_ERROR_CATEGORY_IMPL_HPP_INCLUDED

include/boost/system/detail/error_code.hpp

@@ -0,0 +1,726 @@
+#ifndef BOOST_SYSTEM_DETAIL_ERROR_CODE_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_ERROR_CODE_HPP_INCLUDED
+
+//  Copyright Beman Dawes 2006, 2007
+//  Copyright Christoper Kohlhoff 2007
+//  Copyright Peter Dimov 2017-2021
+//
+//  Distributed under the Boost Software License, Version 1.0. (See accompanying
+//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+//  See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/is_error_code_enum.hpp>
+#include <boost/system/detail/error_category.hpp>
+#include <boost/system/detail/error_condition.hpp>
+#include <boost/system/detail/system_category.hpp>
+#include <boost/system/detail/system_category_impl.hpp>
+#include <boost/system/detail/interop_category.hpp>
+#include <boost/system/detail/enable_if.hpp>
+#include <boost/system/detail/is_same.hpp>
+#include <boost/system/detail/append_int.hpp>
+#include <boost/system/detail/snprintf.hpp>
+#include <boost/system/detail/config.hpp>
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+# include <boost/system/detail/std_category.hpp>
+#endif
+
+#include <boost/assert/source_location.hpp>
+#include <boost/cstdint.hpp>
+#include <boost/config.hpp>
+#include <ostream>
+#include <new>
+#include <cstdio>
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+# include <system_error>
+#endif
+
+#if defined(BOOST_GCC) && BOOST_GCC >= 40600 && BOOST_GCC < 70000
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wstrict-aliasing"
+#endif
+
+namespace boost
+{
+
+namespace system
+{
+
+//  class error_code
+
+//  We want error_code to be a value type that can be copied without slicing
+//  and without requiring heap allocation, but we also want it to have
+//  polymorphic behavior based on the error category. This is achieved by
+//  abstract base class error_category supplying the polymorphic behavior,
+//  and error_code containing a pointer to an object of a type derived
+//  from error_category.
+
+std::size_t hash_value( error_code const & ec );
+
+class error_code
+{
+private:
+
+    friend std::size_t hash_value( error_code const & ec );
+
+private:
+
+    struct data
+    {
+        int val_;
+        const error_category * cat_;
+    };
+
+    union
+    {
+        data d1_;
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+        unsigned char d2_[ sizeof(std::error_code) ];
+#endif
+    };
+
+    // 0: default constructed, d1_ value initialized
+    // 1: holds std::error_code in d2_
+    // 2: holds error code in d1_, failed == false
+    // 3: holds error code in d1_, failed == true
+    // >3: pointer to source_location, failed_ in lsb
+    boost::uintptr_t lc_flags_;
+
+private:
+
+    char const* category_name() const BOOST_NOEXCEPT
+    {
+        // return category().name();
+
+        if( lc_flags_ == 0 )
+        {
+            // must match detail::system_error_category::name()
+            return "system";
+        }
+        else if( lc_flags_ == 1 )
+        {
+            // must match detail::interop_error_category::name()
+            return "std:unknown";
+        }
+        else
+        {
+            return d1_.cat_->name();
+        }
+    }
+
+public:
+
+    // constructors:
+
+    BOOST_SYSTEM_CONSTEXPR error_code() BOOST_NOEXCEPT:
+        d1_(), lc_flags_( 0 )
+    {
+    }
+
+    BOOST_SYSTEM_CONSTEXPR error_code( int val, const error_category & cat ) BOOST_NOEXCEPT:
+        d1_(), lc_flags_( 2 + detail::failed_impl( val, cat ) )
+    {
+        d1_.val_ = val;
+        d1_.cat_ = &cat;
+    }
+
+    error_code( int val, const error_category & cat, source_location const * loc ) BOOST_NOEXCEPT:
+        d1_(), lc_flags_( ( loc? reinterpret_cast<boost::uintptr_t>( loc ): 2 ) | +detail::failed_impl( val, cat ) )
+    {
+        d1_.val_ = val;
+        d1_.cat_ = &cat;
+    }
+
+    template<class ErrorCodeEnum> BOOST_SYSTEM_CONSTEXPR error_code( ErrorCodeEnum e,
+        typename detail::enable_if<
+            is_error_code_enum<ErrorCodeEnum>::value
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+            || std::is_error_code_enum<ErrorCodeEnum>::value
+#endif
+        >::type* = 0 ) BOOST_NOEXCEPT: d1_(), lc_flags_( 0 )
+    {
+        *this = make_error_code( e );
+    }
+
+    error_code( error_code const& ec, source_location const * loc ) BOOST_NOEXCEPT:
+        d1_(), lc_flags_( 0 )
+    {
+        *this = ec;
+
+        if( ec.lc_flags_ != 0 && ec.lc_flags_ != 1 )
+        {
+            lc_flags_ = ( loc? reinterpret_cast<boost::uintptr_t>( loc ): 2 ) | ( ec.lc_flags_ & 1 );
+        }
+    }
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    error_code( std::error_code const& ec ) BOOST_NOEXCEPT:
+        d1_(), lc_flags_( 0 )
+    {
+#ifndef BOOST_NO_RTTI
+
+        if( detail::std_category const* pc2 = dynamic_cast< detail::std_category const* >( &ec.category() ) )
+        {
+            *this = boost::system::error_code( ec.value(), pc2->original_category() );
+        }
+        else
+
+#endif
+        {
+            ::new( d2_ ) std::error_code( ec );
+            lc_flags_ = 1;
+        }
+    }
+
+#endif
+
+    // modifiers:
+
+    BOOST_SYSTEM_CONSTEXPR void assign( int val, const error_category & cat ) BOOST_NOEXCEPT
+    {
+        *this = error_code( val, cat );
+    }
+
+    void assign( int val, const error_category & cat, source_location const * loc ) BOOST_NOEXCEPT
+    {
+        *this = error_code( val, cat, loc );
+    }
+
+    void assign( error_code const& ec, source_location const * loc ) BOOST_NOEXCEPT
+    {
+        *this = error_code( ec, loc );
+    }
+
+    template<typename ErrorCodeEnum>
+        BOOST_SYSTEM_CONSTEXPR typename detail::enable_if<is_error_code_enum<ErrorCodeEnum>::value, error_code>::type &
+        operator=( ErrorCodeEnum val ) BOOST_NOEXCEPT
+    {
+        *this = make_error_code( val );
+        return *this;
+    }
+
+    BOOST_SYSTEM_CONSTEXPR void clear() BOOST_NOEXCEPT
+    {
+        *this = error_code();
+    }
+
+    // observers:
+
+    BOOST_SYSTEM_CONSTEXPR int value() const BOOST_NOEXCEPT
+    {
+        if( lc_flags_ != 1 )
+        {
+            return d1_.val_;
+        }
+        else
+        {
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+            std::error_code const& ec = *reinterpret_cast<std::error_code const*>( d2_ );
+
+            unsigned cv = static_cast<unsigned>( ec.value() );
+            unsigned ch = static_cast<unsigned>( reinterpret_cast<boost::uintptr_t>( &ec.category() ) % 2097143 ); // 2^21-9, prime
+
+            return static_cast<int>( cv + 1000 * ch );
+#else
+
+            return -1;
+#endif
+        }
+    }
+
+    BOOST_SYSTEM_CONSTEXPR const error_category & category() const BOOST_NOEXCEPT
+    {
+        if( lc_flags_ == 0 )
+        {
+            return system_category();
+        }
+        else if( lc_flags_ == 1 )
+        {
+            return detail::interop_category();
+        }
+        else
+        {
+            return *d1_.cat_;
+        }
+    }
+
+    // deprecated?
+    error_condition default_error_condition() const BOOST_NOEXCEPT
+    {
+        return category().default_error_condition( value() );
+    }
+
+    std::string message() const
+    {
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+        if( lc_flags_ == 1 )
+        {
+            std::error_code const& ec = *reinterpret_cast<std::error_code const*>( d2_ );
+            return ec.message();
+        }
+
+#endif
+
+        if( lc_flags_ == 0 )
+        {
+            return detail::system_error_category_message( value() );
+        }
+        else
+        {
+            return category().message( value() );
+        }
+    }
+
+    char const * message( char * buffer, std::size_t len ) const BOOST_NOEXCEPT
+    {
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+        if( lc_flags_ == 1 )
+        {
+            std::error_code const& ec = *reinterpret_cast<std::error_code const*>( d2_ );
+
+#if !defined(BOOST_NO_EXCEPTIONS)
+            try
+#endif
+            {
+                detail::snprintf( buffer, len, "%s", ec.message().c_str() );
+                return buffer;
+            }
+#if !defined(BOOST_NO_EXCEPTIONS)
+            catch( ... )
+            {
+                detail::snprintf( buffer, len, "No message text available for error std:%s:%d", ec.category().name(), ec.value() );
+                return buffer;
+            }
+#endif
+        }
+#endif
+
+        if( lc_flags_ == 0 )
+        {
+            return detail::system_error_category_message( value(), buffer, len );
+        }
+        else
+        {
+            return category().message( value(), buffer, len );
+        }
+    }
+
+    BOOST_SYSTEM_CONSTEXPR bool failed() const BOOST_NOEXCEPT
+    {
+        if( lc_flags_ & 1 )
+        {
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+            if( lc_flags_ == 1 )
+            {
+                std::error_code const& ec = *reinterpret_cast<std::error_code const*>( d2_ );
+                return ec.value() != 0;
+            }
+#endif
+            return true;
+        }
+        else
+        {
+            return false;
+        }
+    }
+
+#if !defined(BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS)
+
+    BOOST_SYSTEM_CONSTEXPR explicit operator bool() const BOOST_NOEXCEPT  // true if error
+    {
+        return failed();
+    }
+
+#else
+
+    typedef void (*unspecified_bool_type)();
+    static void unspecified_bool_true() {}
+
+    BOOST_SYSTEM_CONSTEXPR operator unspecified_bool_type() const  BOOST_NOEXCEPT // true if error
+    {
+        return failed()? unspecified_bool_true: 0;
+    }
+
+    BOOST_SYSTEM_CONSTEXPR bool operator!() const BOOST_NOEXCEPT // true if no error
+    {
+        return !failed();
+    }
+
+#endif
+
+    bool has_location() const BOOST_NOEXCEPT
+    {
+        return lc_flags_ >= 4;
+    }
+
+    source_location const & location() const BOOST_NOEXCEPT
+    {
+        BOOST_STATIC_CONSTEXPR source_location loc;
+        return lc_flags_ >= 4? *reinterpret_cast<source_location const*>( lc_flags_ &~ static_cast<boost::uintptr_t>( 1 ) ): loc;
+    }
+
+    // relationals:
+
+private:
+
+    // private equality for use in error_category::equivalent
+
+    friend class error_category;
+
+    BOOST_SYSTEM_CONSTEXPR bool equals( int val, error_category const& cat ) const BOOST_NOEXCEPT
+    {
+        if( lc_flags_ == 0 )
+        {
+            return val == 0 && cat.id_ == detail::system_category_id;
+        }
+        else if( lc_flags_ == 1 )
+        {
+            return cat.id_ == detail::interop_category_id && val == value();
+        }
+        else
+        {
+            return val == d1_.val_ && cat == *d1_.cat_;
+        }
+    }
+
+public:
+
+    //  the more symmetrical non-member syntax allows enum
+    //  conversions work for both rhs and lhs.
+
+    BOOST_SYSTEM_CONSTEXPR inline friend bool operator==( const error_code & lhs, const error_code & rhs ) BOOST_NOEXCEPT
+    {
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+        if( lhs.lc_flags_ == 1 && rhs.lc_flags_ == 1 )
+        {
+            std::error_code const& e1 = *reinterpret_cast<std::error_code const*>( lhs.d2_ );
+            std::error_code const& e2 = *reinterpret_cast<std::error_code const*>( rhs.d2_ );
+
+            return e1 == e2;
+        }
+        else
+#endif
+        {
+            return lhs.value() == rhs.value() && lhs.category() == rhs.category();
+        }
+    }
+
+    BOOST_SYSTEM_CONSTEXPR inline friend bool operator<( const error_code & lhs, const error_code & rhs ) BOOST_NOEXCEPT
+    {
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+        if( lhs.lc_flags_ == 1 && rhs.lc_flags_ == 1 )
+        {
+            std::error_code const& e1 = *reinterpret_cast<std::error_code const*>( lhs.d2_ );
+            std::error_code const& e2 = *reinterpret_cast<std::error_code const*>( rhs.d2_ );
+
+            return e1 < e2;
+        }
+        else
+#endif
+        {
+            return lhs.category() < rhs.category() || (lhs.category() == rhs.category() && lhs.value() < rhs.value());
+        }
+    }
+
+    BOOST_SYSTEM_CONSTEXPR inline friend bool operator!=( const error_code & lhs, const error_code & rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+    inline friend bool operator==( const error_code & code, const error_condition & condition ) BOOST_NOEXCEPT
+    {
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+        if( code.lc_flags_ == 1 )
+        {
+            return static_cast<std::error_code>( code ) == static_cast<std::error_condition>( condition );
+        }
+        else
+
+#endif
+        {
+            return code.category().equivalent( code.value(), condition ) || condition.category().equivalent( code, condition.value() );
+        }
+    }
+
+    inline friend bool operator==( const error_condition & condition, const error_code & code ) BOOST_NOEXCEPT
+    {
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+        if( code.lc_flags_ == 1 )
+        {
+            return static_cast<std::error_code>( code ) == static_cast<std::error_condition>( condition );
+        }
+        else
+
+#endif
+        {
+            return code.category().equivalent( code.value(), condition ) || condition.category().equivalent( code, condition.value() );
+        }
+    }
+
+    inline friend bool operator!=( const error_code & lhs, const error_condition & rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+    inline friend bool operator!=( const error_condition & lhs, const error_code & rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    inline friend bool operator==( std::error_code const & lhs, error_code const & rhs ) BOOST_NOEXCEPT
+    {
+        return lhs == static_cast< std::error_code >( rhs );
+    }
+
+    inline friend bool operator==( error_code const & lhs, std::error_code const & rhs ) BOOST_NOEXCEPT
+    {
+        return static_cast< std::error_code >( lhs ) == rhs;
+    }
+
+    inline friend bool operator!=( std::error_code const & lhs, error_code const & rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+    inline friend bool operator!=( error_code const & lhs, std::error_code const & rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+    //
+
+    template<class E, class N = typename detail::enable_if<std::is_error_condition_enum<E>::value>::type>
+    inline friend bool operator==( error_code const & lhs, E rhs ) BOOST_NOEXCEPT
+    {
+        return lhs == make_error_condition( rhs );
+    }
+
+    template<class E, class N = typename detail::enable_if<std::is_error_condition_enum<E>::value>::type>
+    inline friend bool operator==( E lhs, error_code const & rhs ) BOOST_NOEXCEPT
+    {
+        return make_error_condition( lhs ) == rhs;
+    }
+
+    template<class E, class N = typename detail::enable_if<std::is_error_condition_enum<E>::value>::type>
+    inline friend bool operator!=( error_code const & lhs, E rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+    template<class E, class N = typename detail::enable_if<std::is_error_condition_enum<E>::value>::type>
+    inline friend bool operator!=( E lhs, error_code const & rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+    //
+
+    template<class E, class N1 = void, class N2 = typename detail::enable_if<std::is_error_code_enum<E>::value>::type>
+    BOOST_SYSTEM_CONSTEXPR inline friend bool operator==( error_code const & lhs, E rhs ) BOOST_NOEXCEPT
+    {
+        return lhs == make_error_code( rhs );
+    }
+
+    template<class E, class N1 = void, class N2 = typename detail::enable_if<std::is_error_code_enum<E>::value>::type>
+    BOOST_SYSTEM_CONSTEXPR inline friend bool operator==( E lhs, error_code const & rhs ) BOOST_NOEXCEPT
+    {
+        return make_error_code( lhs ) == rhs;
+    }
+
+    template<class E, class N1 = void, class N2 = typename detail::enable_if<std::is_error_code_enum<E>::value>::type>
+    BOOST_SYSTEM_CONSTEXPR inline friend bool operator!=( error_code const & lhs, E rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+    template<class E, class N1 = void, class N2 = typename detail::enable_if<std::is_error_code_enum<E>::value>::type>
+    BOOST_SYSTEM_CONSTEXPR inline friend bool operator!=( E lhs, error_code const & rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+#if defined(BOOST_SYSTEM_CLANG_6)
+
+    inline friend bool operator==( error_code const & lhs, std::error_condition const & rhs ) BOOST_NOEXCEPT
+    {
+        return static_cast< std::error_code >( lhs ) == rhs;
+    }
+
+    inline friend bool operator==( std::error_condition const & lhs, error_code const & rhs ) BOOST_NOEXCEPT
+    {
+        return lhs == static_cast< std::error_code >( rhs );
+    }
+
+    inline friend bool operator!=( error_code const & lhs, std::error_condition const & rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+    inline friend bool operator!=( std::error_condition const & lhs, error_code const & rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+#endif
+
+    // conversions
+
+    operator std::error_code () const
+    {
+        if( lc_flags_ == 1 )
+        {
+            return *reinterpret_cast<std::error_code const*>( d2_ );
+        }
+        else if( lc_flags_ == 0 )
+        {
+// This condition must be the same as the one in error_category_impl.hpp
+#if defined(BOOST_SYSTEM_AVOID_STD_SYSTEM_CATEGORY)
+
+            return std::error_code( 0, boost::system::system_category() );
+
+#else
+
+            return std::error_code();
+
+#endif
+        }
+        else
+        {
+            return std::error_code( d1_.val_, *d1_.cat_ );
+        }
+    }
+
+    operator std::error_code ()
+    {
+        return const_cast<error_code const&>( *this );
+    }
+
+    template<class T,
+      class E = typename detail::enable_if<detail::is_same<T, std::error_code>::value>::type>
+      operator T& ()
+    {
+        if( lc_flags_ != 1 )
+        {
+            std::error_code e2( *this );
+            ::new( d2_ ) std::error_code( e2 );
+            lc_flags_ = 1;
+        }
+
+        return *reinterpret_cast<std::error_code*>( d2_ );
+    }
+
+#if defined(BOOST_SYSTEM_CLANG_6)
+
+    template<class T,
+      class E = typename std::enable_if<std::is_same<T, std::error_code>::value>::type>
+      operator T const& () = delete;
+
+#endif
+
+#endif
+
+    std::string to_string() const
+    {
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+        if( lc_flags_ == 1 )
+        {
+            std::error_code const& e2 = *reinterpret_cast<std::error_code const*>( d2_ );
+
+            std::string r( "std:" );
+            r += e2.category().name();
+            detail::append_int( r, e2.value() );
+
+            return r;
+        }
+        else
+#endif
+        {
+            std::string r = category_name();
+            detail::append_int( r, value() );
+            return r;
+        }
+    }
+
+    template<class Ch, class Tr>
+        inline friend std::basic_ostream<Ch, Tr>&
+        operator<< (std::basic_ostream<Ch, Tr>& os, error_code const & ec)
+    {
+        return os << ec.to_string().c_str();
+    }
+
+    std::string what() const
+    {
+        std::string r = message();
+
+        r += " [";
+        r += to_string();
+
+        if( has_location() )
+        {
+            r += " at ";
+            r += location().to_string();
+        }
+
+        r += "]";
+        return r;
+    }
+};
+
+inline std::size_t hash_value( error_code const & ec )
+{
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    if( ec.lc_flags_ == 1 )
+    {
+        std::error_code const& e2 = *reinterpret_cast<std::error_code const*>( ec.d2_ );
+        return std::hash<std::error_code>()( e2 );
+    }
+
+#endif
+
+    error_category const & cat = ec.category();
+
+    boost::ulong_long_type id_ = cat.id_;
+
+    if( id_ == 0 )
+    {
+        id_ = reinterpret_cast<boost::uintptr_t>( &cat );
+    }
+
+    boost::ulong_long_type hv = ( boost::ulong_long_type( 0xCBF29CE4 ) << 32 ) + 0x84222325;
+    boost::ulong_long_type const prime = ( boost::ulong_long_type( 0x00000100 ) << 32 ) + 0x000001B3;
+
+    // id
+
+    hv ^= id_;
+    hv *= prime;
+
+    // value
+
+    hv ^= static_cast<unsigned>( ec.value() );
+    hv *= prime;
+
+    return static_cast<std::size_t>( hv );
+}
+
+} // namespace system
+
+} // namespace boost
+
+#if defined(BOOST_GCC) && BOOST_GCC >= 40600 && BOOST_GCC < 70000
+# pragma GCC diagnostic pop
+#endif
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_ERROR_CODE_HPP_INCLUDED

include/boost/system/detail/error_condition.hpp

@@ -0,0 +1,297 @@
+#ifndef BOOST_SYSTEM_DETAIL_ERROR_CONDITION_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_ERROR_CONDITION_HPP_INCLUDED
+
+//  Copyright Beman Dawes 2006, 2007
+//  Copyright Christoper Kohlhoff 2007
+//  Copyright Peter Dimov 2017-2021
+//
+//  Distributed under the Boost Software License, Version 1.0. (See accompanying
+//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+//  See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/error_category.hpp>
+#include <boost/system/detail/generic_category.hpp>
+#include <boost/system/detail/enable_if.hpp>
+#include <boost/system/detail/is_same.hpp>
+#include <boost/system/detail/errc.hpp>
+#include <boost/system/detail/append_int.hpp>
+#include <boost/system/is_error_condition_enum.hpp>
+#include <boost/system/detail/config.hpp>
+#include <boost/config.hpp>
+
+namespace boost
+{
+
+namespace system
+{
+
+// class error_condition
+
+// error_conditions are portable, error_codes are system or library specific
+
+namespace detail
+{
+
+struct generic_value_tag
+{
+    int value;
+    BOOST_SYSTEM_CONSTEXPR explicit generic_value_tag( int v ): value( v ) {}
+};
+
+} // namespace detail
+
+class error_condition
+{
+private:
+
+    int val_;
+    error_category const * cat_;
+
+private:
+
+    boost::ulong_long_type cat_id() const BOOST_NOEXCEPT
+    {
+        return cat_? cat_->id_: detail::generic_category_id;
+    }
+
+public:
+
+    // constructors:
+
+    BOOST_SYSTEM_CONSTEXPR error_condition() BOOST_NOEXCEPT:
+        val_( 0 ), cat_( 0 )
+    {
+    }
+
+    BOOST_SYSTEM_CONSTEXPR error_condition( int val, const error_category & cat ) BOOST_NOEXCEPT:
+        val_( val ), cat_( &cat )
+    {
+    }
+
+    BOOST_SYSTEM_CONSTEXPR explicit error_condition( boost::system::detail::generic_value_tag vt ) BOOST_NOEXCEPT:
+        val_( vt.value ), cat_( 0 )
+    {
+    }
+
+    template<class ErrorConditionEnum> BOOST_SYSTEM_CONSTEXPR error_condition( ErrorConditionEnum e,
+      typename detail::enable_if<
+        is_error_condition_enum<ErrorConditionEnum>::value && !boost::system::detail::is_same<ErrorConditionEnum, errc::errc_t>::value
+      >::type* = 0) BOOST_NOEXCEPT
+    {
+        *this = make_error_condition( e );
+    }
+
+    template<class ErrorConditionEnum> BOOST_SYSTEM_CONSTEXPR error_condition( ErrorConditionEnum e,
+      typename detail::enable_if<boost::system::detail::is_same<ErrorConditionEnum, errc::errc_t>::value>::type* = 0) BOOST_NOEXCEPT:
+        val_( e ), cat_( 0 )
+    {
+    }
+
+    // modifiers:
+
+    BOOST_SYSTEM_CONSTEXPR void assign( int val, const error_category & cat ) BOOST_NOEXCEPT
+    {
+        val_ = val;
+        cat_ = &cat;
+    }
+
+    template<typename ErrorConditionEnum>
+        BOOST_SYSTEM_CONSTEXPR typename detail::enable_if<is_error_condition_enum<ErrorConditionEnum>::value, error_condition>::type &
+        operator=( ErrorConditionEnum val ) BOOST_NOEXCEPT
+    {
+        *this = error_condition( val );
+        return *this;
+    }
+
+    BOOST_SYSTEM_CONSTEXPR void clear() BOOST_NOEXCEPT
+    {
+        val_ = 0;
+        cat_ = 0;
+    }
+
+    // observers:
+
+    BOOST_SYSTEM_CONSTEXPR int value() const BOOST_NOEXCEPT
+    {
+        return val_;
+    }
+
+    BOOST_SYSTEM_CONSTEXPR const error_category & category() const BOOST_NOEXCEPT
+    {
+        return cat_? *cat_: generic_category();
+    }
+
+    std::string message() const
+    {
+        if( cat_ )
+        {
+            return cat_->message( value() );
+        }
+        else
+        {
+            return detail::generic_error_category_message( value() );
+        }
+    }
+
+    char const * message( char * buffer, std::size_t len ) const BOOST_NOEXCEPT
+    {
+        if( cat_ )
+        {
+            return cat_->message( value(), buffer, len );
+        }
+        else
+        {
+            return detail::generic_error_category_message( value(), buffer, len );
+        }
+    }
+
+    BOOST_SYSTEM_CONSTEXPR bool failed() const BOOST_NOEXCEPT
+    {
+        if( cat_ )
+        {
+            return detail::failed_impl( val_, *cat_ );
+        }
+        else
+        {
+            return val_ != 0;
+        }
+    }
+
+#if !defined(BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS)
+
+    BOOST_SYSTEM_CONSTEXPR explicit operator bool() const BOOST_NOEXCEPT  // true if error
+    {
+        return failed();
+    }
+
+#else
+
+    typedef void (*unspecified_bool_type)();
+    static void unspecified_bool_true() {}
+
+    BOOST_SYSTEM_CONSTEXPR operator unspecified_bool_type() const BOOST_NOEXCEPT  // true if error
+    {
+        return failed()? unspecified_bool_true: 0;
+    }
+
+    BOOST_SYSTEM_CONSTEXPR bool operator!() const BOOST_NOEXCEPT  // true if no error
+    {
+        return !failed();
+    }
+
+#endif
+
+    // relationals:
+    //  the more symmetrical non-member syntax allows enum
+    //  conversions work for both rhs and lhs.
+
+    BOOST_SYSTEM_CONSTEXPR inline friend bool operator==( const error_condition & lhs, const error_condition & rhs ) BOOST_NOEXCEPT
+    {
+        if( lhs.val_ != rhs.val_ )
+        {
+            return false;
+        }
+        else if( lhs.cat_ == 0 )
+        {
+            return rhs.cat_id() == detail::generic_category_id;
+        }
+        else if( rhs.cat_ == 0 )
+        {
+            return lhs.cat_id() == detail::generic_category_id;
+        }
+        else
+        {
+            return *lhs.cat_ == *rhs.cat_;
+        }
+    }
+
+    BOOST_SYSTEM_CONSTEXPR inline friend bool operator<( const error_condition & lhs, const error_condition & rhs ) BOOST_NOEXCEPT
+    {
+        error_category const& lcat = lhs.category();
+        error_category const& rcat = rhs.category();
+        return lcat < rcat || ( lcat == rcat && lhs.val_ < rhs.val_ );
+    }
+
+    BOOST_SYSTEM_CONSTEXPR inline friend bool operator!=( const error_condition & lhs, const error_condition & rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    operator std::error_condition () const
+    {
+// This condition must be the same as the one in error_category_impl.hpp
+#if defined(BOOST_SYSTEM_AVOID_STD_GENERIC_CATEGORY)
+
+        return std::error_condition( value(), category() );
+
+#else
+
+        if( cat_ )
+        {
+            return std::error_condition( val_, *cat_ );
+        }
+        else
+        {
+            return std::error_condition( val_, std::generic_category() );
+        }
+
+#endif
+    }
+
+    inline friend bool operator==( std::error_code const & lhs, error_condition const & rhs ) BOOST_NOEXCEPT
+    {
+        return lhs == static_cast< std::error_condition >( rhs );
+    }
+
+    inline friend bool operator==( error_condition const & lhs, std::error_code const & rhs ) BOOST_NOEXCEPT
+    {
+        return static_cast< std::error_condition >( lhs ) == rhs;
+    }
+
+    inline friend bool operator!=( std::error_code const & lhs, error_condition const & rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+    inline friend bool operator!=( error_condition const & lhs, std::error_code const & rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+#endif
+
+    std::string to_string() const
+    {
+        std::string r( "cond:" );
+
+        if( cat_ )
+        {
+            r += cat_->name();
+        }
+        else
+        {
+            r += "generic";
+        }
+
+        detail::append_int( r, value() );
+
+        return r;
+    }
+
+    template<class Ch, class Tr>
+        inline friend std::basic_ostream<Ch, Tr>&
+        operator<< (std::basic_ostream<Ch, Tr>& os, error_condition const & en)
+    {
+        os << en.to_string();
+        return os;
+    }
+};
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_ERROR_CONDITION_HPP_INCLUDED

include/boost/system/detail/generic_category.hpp

@@ -0,0 +1,123 @@
+#ifndef BOOST_SYSTEM_DETAIL_GENERIC_CATEGORY_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_GENERIC_CATEGORY_HPP_INCLUDED
+
+//  Copyright Beman Dawes 2006, 2007
+//  Copyright Christoper Kohlhoff 2007
+//  Copyright Peter Dimov 2017, 2018
+//
+//  Distributed under the Boost Software License, Version 1.0. (See accompanying
+//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+//  See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/error_category.hpp>
+#include <boost/system/detail/generic_category_message.hpp>
+#include <boost/system/detail/config.hpp>
+#include <boost/config.hpp>
+
+namespace boost
+{
+
+namespace system
+{
+
+namespace detail
+{
+
+// generic_error_category
+
+#if ( defined( BOOST_GCC ) && BOOST_GCC >= 40600 ) || defined( BOOST_CLANG )
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
+#endif
+
+class BOOST_SYMBOL_VISIBLE generic_error_category: public error_category
+{
+public:
+
+    BOOST_SYSTEM_CONSTEXPR generic_error_category() BOOST_NOEXCEPT:
+        error_category( detail::generic_category_id )
+    {
+    }
+
+    const char * name() const BOOST_NOEXCEPT BOOST_OVERRIDE
+    {
+        return "generic";
+    }
+
+    std::string message( int ev ) const BOOST_OVERRIDE;
+    char const * message( int ev, char * buffer, std::size_t len ) const BOOST_NOEXCEPT BOOST_OVERRIDE;
+};
+
+#if ( defined( BOOST_GCC ) && BOOST_GCC >= 40600 ) || defined( BOOST_CLANG )
+#pragma GCC diagnostic pop
+#endif
+
+// generic_error_category::message
+
+inline char const * generic_error_category::message( int ev, char * buffer, std::size_t len ) const BOOST_NOEXCEPT
+{
+    return generic_error_category_message( ev, buffer, len );
+}
+
+inline std::string generic_error_category::message( int ev ) const
+{
+    return generic_error_category_message( ev );
+}
+
+} // namespace detail
+
+// generic_category()
+
+#if defined(BOOST_SYSTEM_HAS_CONSTEXPR)
+
+namespace detail
+{
+
+template<class T> struct BOOST_SYMBOL_VISIBLE generic_cat_holder
+{
+    static constexpr generic_error_category instance{};
+};
+
+// Before C++17 it was mandatory to redeclare all static constexpr
+#if defined(BOOST_NO_CXX17_INLINE_VARIABLES)
+template<class T> constexpr generic_error_category generic_cat_holder<T>::instance;
+#endif
+
+} // namespace detail
+
+constexpr error_category const & generic_category() BOOST_NOEXCEPT
+{
+    return detail::generic_cat_holder<void>::instance;
+}
+
+#else // #if defined(BOOST_SYSTEM_HAS_CONSTEXPR)
+
+#if !defined(__SUNPRO_CC) // trailing __global is not supported
+inline error_category const & generic_category() BOOST_NOEXCEPT BOOST_SYMBOL_VISIBLE;
+#endif
+
+inline error_category const & generic_category() BOOST_NOEXCEPT
+{
+    static const detail::generic_error_category instance;
+    return instance;
+}
+
+#endif // #if defined(BOOST_SYSTEM_HAS_CONSTEXPR)
+
+// deprecated synonyms
+
+#ifdef BOOST_SYSTEM_ENABLE_DEPRECATED
+
+BOOST_SYSTEM_DEPRECATED("please use generic_category()") inline const error_category & get_generic_category() { return generic_category(); }
+BOOST_SYSTEM_DEPRECATED("please use generic_category()") inline const error_category & get_posix_category() { return generic_category(); }
+BOOST_SYSTEM_DEPRECATED("please use generic_category()") static const error_category & posix_category BOOST_ATTRIBUTE_UNUSED = generic_category();
+BOOST_SYSTEM_DEPRECATED("please use generic_category()") static const error_category & errno_ecat BOOST_ATTRIBUTE_UNUSED = generic_category();
+
+#endif
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_GENERIC_CATEGORY_HPP_INCLUDED

include/boost/system/detail/generic_category_message.hpp

@@ -0,0 +1,108 @@
+#ifndef BOOST_SYSTEM_DETAIL_GENERIC_CATEGORY_MESSAGE_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_GENERIC_CATEGORY_MESSAGE_HPP_INCLUDED
+
+// Implementation of generic_error_category_message
+//
+// Copyright 2018 Peter Dimov
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// See library home page at http://www.boost.org/libs/system
+
+#include <boost/config.hpp>
+#include <string>
+#include <cstring>
+
+namespace boost
+{
+
+namespace system
+{
+
+namespace detail
+{
+
+#if defined(__GLIBC__)
+
+// glibc has two incompatible strerror_r definitions
+
+inline char const * strerror_r_helper( char const * r, char const * ) BOOST_NOEXCEPT
+{
+    return r;
+}
+
+inline char const * strerror_r_helper( int r, char const * buffer ) BOOST_NOEXCEPT
+{
+    return r == 0? buffer: "Unknown error";
+}
+
+inline char const * generic_error_category_message( int ev, char * buffer, std::size_t len ) BOOST_NOEXCEPT
+{
+    return strerror_r_helper( strerror_r( ev, buffer, len ), buffer );
+}
+
+inline std::string generic_error_category_message( int ev )
+{
+    char buffer[ 128 ];
+    return generic_error_category_message( ev, buffer, sizeof( buffer ) );
+}
+
+#else // #if defined(__GLIBC__)
+
+// std::strerror is thread-safe on everything else, incl. Windows
+
+# if defined( BOOST_MSVC )
+#  pragma warning( push )
+#  pragma warning( disable: 4996 )
+# elif defined(__clang__) && defined(__has_warning)
+#  pragma clang diagnostic push
+#  if __has_warning("-Wdeprecated-declarations")
+#   pragma clang diagnostic ignored "-Wdeprecated-declarations"
+#  endif
+# endif
+
+inline std::string generic_error_category_message( int ev )
+{
+    char const * m = std::strerror( ev );
+    return m? m: "Unknown error";
+}
+
+inline char const * generic_error_category_message( int ev, char * buffer, std::size_t len ) BOOST_NOEXCEPT
+{
+    if( len == 0 )
+    {
+        return buffer;
+    }
+
+    if( len == 1 )
+    {
+        buffer[0] = 0;
+        return buffer;
+    }
+
+    char const * m = std::strerror( ev );
+
+    if( m == 0 ) return "Unknown error";
+
+    std::strncpy( buffer, m, len - 1 );
+    buffer[ len-1 ] = 0;
+
+    return buffer;
+}
+
+# if defined( BOOST_MSVC )
+#  pragma warning( pop )
+# elif defined(__clang__) && defined(__has_warning)
+#  pragma clang diagnostic pop
+# endif
+
+#endif // #if defined(__GLIBC__)
+
+} // namespace detail
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_GENERIC_CATEGORY_MESSAGE_HPP_INCLUDED

include/boost/system/detail/interop_category.hpp

@@ -0,0 +1,107 @@
+#ifndef BOOST_SYSTEM_DETAIL_INTEROP_CATEGORY_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_INTEROP_CATEGORY_HPP_INCLUDED
+
+//  Copyright Beman Dawes 2006, 2007
+//  Copyright Christoper Kohlhoff 2007
+//  Copyright Peter Dimov 2017, 2018, 2021
+//
+//  Distributed under the Boost Software License, Version 1.0. (See accompanying
+//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+//  See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/error_category.hpp>
+#include <boost/system/detail/snprintf.hpp>
+#include <boost/system/detail/config.hpp>
+#include <boost/config.hpp>
+
+namespace boost
+{
+
+namespace system
+{
+
+namespace detail
+{
+
+// interop_error_category, used for std::error_code
+
+#if ( defined( BOOST_GCC ) && BOOST_GCC >= 40600 ) || defined( BOOST_CLANG )
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
+#endif
+
+class BOOST_SYMBOL_VISIBLE interop_error_category: public error_category
+{
+public:
+
+    BOOST_SYSTEM_CONSTEXPR interop_error_category() BOOST_NOEXCEPT:
+        error_category( detail::interop_category_id )
+    {
+    }
+
+    const char * name() const BOOST_NOEXCEPT BOOST_OVERRIDE
+    {
+        return "std:unknown";
+    }
+
+    std::string message( int ev ) const BOOST_OVERRIDE;
+    char const * message( int ev, char * buffer, std::size_t len ) const BOOST_NOEXCEPT BOOST_OVERRIDE;
+};
+
+#if ( defined( BOOST_GCC ) && BOOST_GCC >= 40600 ) || defined( BOOST_CLANG )
+#pragma GCC diagnostic pop
+#endif
+
+inline char const * interop_error_category::message( int ev, char * buffer, std::size_t len ) const BOOST_NOEXCEPT
+{
+    detail::snprintf( buffer, len, "Unknown interop error %d", ev );
+    return buffer;
+}
+
+inline std::string interop_error_category::message( int ev ) const
+{
+    char buffer[ 48 ];
+    return message( ev, buffer, sizeof( buffer ) );
+}
+
+// interop_category()
+
+#if defined(BOOST_SYSTEM_HAS_CONSTEXPR)
+
+template<class T> struct BOOST_SYMBOL_VISIBLE interop_cat_holder
+{
+    static constexpr interop_error_category instance{};
+};
+
+// Before C++17 it was mandatory to redeclare all static constexpr
+#if defined(BOOST_NO_CXX17_INLINE_VARIABLES)
+template<class T> constexpr interop_error_category interop_cat_holder<T>::instance;
+#endif
+
+constexpr error_category const & interop_category() BOOST_NOEXCEPT
+{
+    return interop_cat_holder<void>::instance;
+}
+
+#else // #if defined(BOOST_SYSTEM_HAS_CONSTEXPR)
+
+#if !defined(__SUNPRO_CC) // trailing __global is not supported
+inline error_category const & interop_category() BOOST_NOEXCEPT BOOST_SYMBOL_VISIBLE;
+#endif
+
+inline error_category const & interop_category() BOOST_NOEXCEPT
+{
+    static const detail::interop_error_category instance;
+    return instance;
+}
+
+#endif // #if defined(BOOST_SYSTEM_HAS_CONSTEXPR)
+
+} // namespace detail
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_INTEROP_CATEGORY_HPP_INCLUDED

include/boost/system/detail/is_same.hpp

@@ -0,0 +1,33 @@
+#ifndef BOOST_SYSTEM_DETAIL_IS_SAME_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_IS_SAME_HPP_INCLUDED
+
+// Copyright 2021 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0
+// http://www.boost.org/LICENSE_1_0.txt
+
+namespace boost
+{
+
+namespace system
+{
+
+namespace detail
+{
+
+template<class T1, class T2> struct is_same
+{
+    enum _vt { value = 0 };
+};
+
+template<class T> struct is_same<T, T>
+{
+    enum _vt { value = 1 };
+};
+
+} // namespace detail
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_IS_SAME_HPP_INCLUDED

include/boost/system/detail/snprintf.hpp

@@ -0,0 +1,73 @@
+#ifndef BOOST_SYSTEM_DETAIL_SNPRINTF_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_SNPRINTF_HPP_INCLUDED
+
+// Copyright 2018, 2020, 2021 Peter Dimov
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// See library home page at http://www.boost.org/libs/system
+
+#include <boost/config.hpp>
+#include <cstdio>
+#include <cstdarg>
+
+//
+
+namespace boost
+{
+
+namespace system
+{
+
+namespace detail
+{
+
+#if ( defined(_MSC_VER) && _MSC_VER < 1900 ) || ( defined(__MINGW32__) && !defined(__MINGW64_VERSION_MAJOR) )
+
+inline void snprintf( char * buffer, std::size_t len, char const * format, ... )
+{
+# if defined( BOOST_MSVC )
+#  pragma warning( push )
+#  pragma warning( disable: 4996 )
+# endif
+
+    if( len == 0 ) return;
+
+    va_list args;
+    va_start( args, format );
+
+    _vsnprintf( buffer, len - 1, format, args );
+    buffer[ len - 1 ] = 0;
+
+    va_end( args );
+
+# if defined( BOOST_MSVC )
+#  pragma warning( pop )
+# endif
+}
+
+#else
+
+#if defined(__GNUC__) && __GNUC__ >= 3
+__attribute__((__format__ (__printf__, 3, 4)))
+#endif
+inline void snprintf( char * buffer, std::size_t len, char const * format, ... )
+{
+    va_list args;
+    va_start( args, format );
+
+    std::vsnprintf( buffer, len, format, args );
+
+    va_end( args );
+}
+
+#endif
+
+} // namespace detail
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_SNPRINTF_HPP_INCLUDED

include/boost/system/detail/std_category.hpp

@@ -0,0 +1,83 @@
+#ifndef BOOST_SYSTEM_DETAIL_STD_CATEGORY_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_STD_CATEGORY_HPP_INCLUDED
+
+// Support for interoperability between Boost.System and <system_error>
+//
+// Copyright 2018, 2021 Peter Dimov
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/error_category.hpp>
+#include <system_error>
+
+//
+
+namespace boost
+{
+
+namespace system
+{
+
+namespace detail
+{
+
+class BOOST_SYMBOL_VISIBLE std_category: public std::error_category
+{
+private:
+
+    boost::system::error_category const * pc_;
+
+public:
+
+    boost::system::error_category const & original_category() const BOOST_NOEXCEPT
+    {
+        return *pc_;
+    }
+
+public:
+
+    explicit std_category( boost::system::error_category const * pc, unsigned id ): pc_( pc )
+    {
+        if( id != 0 )
+        {
+#if defined(_MSC_VER) && defined(_CPPLIB_VER) && _MSC_VER >= 1900 && _MSC_VER < 2000
+
+            // Poking into the protected _Addr member of std::error_category
+            // is not a particularly good programming practice, but what can
+            // you do
+
+            _Addr = id;
+
+#endif
+        }
+    }
+
+    const char * name() const BOOST_NOEXCEPT BOOST_OVERRIDE
+    {
+        return pc_->name();
+    }
+
+    std::string message( int ev ) const BOOST_OVERRIDE
+    {
+        return pc_->message( ev );
+    }
+
+    std::error_condition default_error_condition( int ev ) const BOOST_NOEXCEPT BOOST_OVERRIDE
+    {
+        return pc_->default_error_condition( ev );
+    }
+
+    inline bool equivalent( int code, const std::error_condition & condition ) const BOOST_NOEXCEPT BOOST_OVERRIDE;
+    inline bool equivalent( const std::error_code & code, int condition ) const BOOST_NOEXCEPT BOOST_OVERRIDE;
+};
+
+} // namespace detail
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_STD_CATEGORY_HPP_INCLUDED

include/boost/system/detail/std_category_impl.hpp

@@ -0,0 +1,97 @@
+#ifndef BOOST_SYSTEM_DETAIL_STD_CATEGORY_IMPL_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_STD_CATEGORY_IMPL_HPP_INCLUDED
+
+// Support for interoperability between Boost.System and <system_error>
+//
+// Copyright 2018, 2021 Peter Dimov
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/std_category.hpp>
+#include <boost/system/detail/error_condition.hpp>
+#include <boost/system/detail/error_code.hpp>
+#include <boost/system/detail/generic_category.hpp>
+
+//
+
+namespace boost
+{
+
+namespace system
+{
+
+namespace detail
+{
+
+inline bool std_category::equivalent( int code, const std::error_condition & condition ) const BOOST_NOEXCEPT
+{
+    if( condition.category() == *this )
+    {
+        boost::system::error_condition bn( condition.value(), *pc_ );
+        return pc_->equivalent( code, bn );
+    }
+    else if( condition.category() == std::generic_category() || condition.category() == boost::system::generic_category() )
+    {
+        boost::system::error_condition bn( condition.value(), boost::system::generic_category() );
+        return pc_->equivalent( code, bn );
+    }
+
+#ifndef BOOST_NO_RTTI
+
+    else if( std_category const* pc2 = dynamic_cast< std_category const* >( &condition.category() ) )
+    {
+        boost::system::error_condition bn( condition.value(), *pc2->pc_ );
+        return pc_->equivalent( code, bn );
+    }
+
+#endif
+
+    else
+    {
+        return default_error_condition( code ) == condition;
+    }
+}
+
+inline bool std_category::equivalent( const std::error_code & code, int condition ) const BOOST_NOEXCEPT
+{
+    if( code.category() == *this )
+    {
+        boost::system::error_code bc( code.value(), *pc_ );
+        return pc_->equivalent( bc, condition );
+    }
+    else if( code.category() == std::generic_category() || code.category() == boost::system::generic_category() )
+    {
+        boost::system::error_code bc( code.value(), boost::system::generic_category() );
+        return pc_->equivalent( bc, condition );
+    }
+
+#ifndef BOOST_NO_RTTI
+
+    else if( std_category const* pc2 = dynamic_cast< std_category const* >( &code.category() ) )
+    {
+        boost::system::error_code bc( code.value(), *pc2->pc_ );
+        return pc_->equivalent( bc, condition );
+    }
+
+#endif
+
+    else if( *pc_ == boost::system::generic_category() )
+    {
+        return std::generic_category().equivalent( code, condition );
+    }
+    else
+    {
+        return false;
+    }
+}
+
+} // namespace detail
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_STD_CATEGORY_IMPL_HPP_INCLUDED

include/boost/system/detail/system_category.hpp

@@ -0,0 +1,110 @@
+#ifndef BOOST_SYSTEM_DETAIL_SYSTEM_CATEGORY_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_SYSTEM_CATEGORY_HPP_INCLUDED
+
+//  Copyright Beman Dawes 2006, 2007
+//  Copyright Christoper Kohlhoff 2007
+//  Copyright Peter Dimov 2017, 2018
+//
+//  Distributed under the Boost Software License, Version 1.0. (See accompanying
+//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+//  See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/error_category.hpp>
+#include <boost/system/detail/config.hpp>
+#include <boost/config.hpp>
+
+namespace boost
+{
+
+namespace system
+{
+
+namespace detail
+{
+
+// system_error_category
+
+#if ( defined( BOOST_GCC ) && BOOST_GCC >= 40600 ) || defined( BOOST_CLANG )
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
+#endif
+
+class BOOST_SYMBOL_VISIBLE system_error_category: public error_category
+{
+public:
+
+    BOOST_SYSTEM_CONSTEXPR system_error_category() BOOST_NOEXCEPT:
+        error_category( detail::system_category_id )
+    {
+    }
+
+    const char * name() const BOOST_NOEXCEPT BOOST_OVERRIDE
+    {
+        return "system";
+    }
+
+    error_condition default_error_condition( int ev ) const BOOST_NOEXCEPT BOOST_OVERRIDE;
+
+    std::string message( int ev ) const BOOST_OVERRIDE;
+    char const * message( int ev, char * buffer, std::size_t len ) const BOOST_NOEXCEPT BOOST_OVERRIDE;
+};
+
+#if ( defined( BOOST_GCC ) && BOOST_GCC >= 40600 ) || defined( BOOST_CLANG )
+#pragma GCC diagnostic pop
+#endif
+
+} // namespace detail
+
+// system_category()
+
+#if defined(BOOST_SYSTEM_HAS_CONSTEXPR)
+
+namespace detail
+{
+
+template<class T> struct BOOST_SYMBOL_VISIBLE system_cat_holder
+{
+    static constexpr system_error_category instance{};
+};
+
+// Before C++17 it was mandatory to redeclare all static constexpr
+#if defined(BOOST_NO_CXX17_INLINE_VARIABLES)
+template<class T> constexpr system_error_category system_cat_holder<T>::instance;
+#endif
+
+} // namespace detail
+
+constexpr error_category const & system_category() BOOST_NOEXCEPT
+{
+    return detail::system_cat_holder<void>::instance;
+}
+
+#else // #if defined(BOOST_SYSTEM_HAS_CONSTEXPR)
+
+#if !defined(__SUNPRO_CC) // trailing __global is not supported
+inline error_category const & system_category() BOOST_NOEXCEPT BOOST_SYMBOL_VISIBLE;
+#endif
+
+inline error_category const & system_category() BOOST_NOEXCEPT
+{
+    static const detail::system_error_category instance;
+    return instance;
+}
+
+#endif // #if defined(BOOST_SYSTEM_HAS_CONSTEXPR)
+
+// deprecated synonyms
+
+#ifdef BOOST_SYSTEM_ENABLE_DEPRECATED
+
+BOOST_SYSTEM_DEPRECATED("please use system_category()") inline const error_category & get_system_category() { return system_category(); }
+BOOST_SYSTEM_DEPRECATED("please use system_category()") static const error_category & native_ecat BOOST_ATTRIBUTE_UNUSED = system_category();
+
+#endif
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_SYSTEM_CATEGORY_HPP_INCLUDED

include/boost/system/detail/system_category_condition_win32.hpp

@@ -0,0 +1,151 @@
+#ifndef BOOST_SYSTEM_DETAIL_SYSTEM_CATEGORY_CONDITION_WIN32_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_SYSTEM_CATEGORY_CONDITION_WIN32_HPP_INCLUDED
+
+// Copyright Beman Dawes 2002, 2006
+// Copyright (c) Microsoft Corporation 2014
+// Copyright 2018 Peter Dimov
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/errc.hpp>
+#include <boost/winapi/error_codes.hpp>
+#include <boost/config.hpp>
+
+//
+
+namespace boost
+{
+
+namespace system
+{
+
+namespace detail
+{
+
+inline int system_category_condition_win32( int ev ) BOOST_NOEXCEPT
+{
+    // When using the Windows Runtime, most system errors are reported as HRESULTs.
+    // We want to map the common Win32 errors to their equivalent error condition,
+    // whether or not they are reported via an HRESULT.
+
+#define BOOST_SYSTEM_FAILED(hr)           ((hr) < 0)
+#define BOOST_SYSTEM_HRESULT_FACILITY(hr) (((hr) >> 16) & 0x1fff)
+#define BOOST_SYSTEM_HRESULT_CODE(hr)     ((hr) & 0xFFFF)
+#define BOOST_SYSTEM_FACILITY_WIN32       7
+
+    if( BOOST_SYSTEM_FAILED( ev ) && BOOST_SYSTEM_HRESULT_FACILITY( ev ) == BOOST_SYSTEM_FACILITY_WIN32 )
+    {
+        ev = BOOST_SYSTEM_HRESULT_CODE( ev );
+    }
+
+#undef BOOST_SYSTEM_FAILED
+#undef BOOST_SYSTEM_HRESULT_FACILITY
+#undef BOOST_SYSTEM_HRESULT_CODE
+#undef BOOST_SYSTEM_FACILITY_WIN32
+
+    using namespace boost::winapi;
+    using namespace errc;
+
+    // Windows system -> posix_errno decode table
+    // see WinError.h comments for descriptions of errors
+
+    switch ( ev )
+    {
+    case 0: return success;
+
+    case ERROR_ACCESS_DENIED_: return permission_denied;
+    case ERROR_ALREADY_EXISTS_: return file_exists;
+    case ERROR_BAD_NETPATH_: return no_such_file_or_directory;
+    case ERROR_BAD_UNIT_: return no_such_device;
+    case ERROR_BROKEN_PIPE_: return broken_pipe;
+    case ERROR_BUFFER_OVERFLOW_: return filename_too_long;
+    case ERROR_BUSY_: return device_or_resource_busy;
+    case ERROR_BUSY_DRIVE_: return device_or_resource_busy;
+    case ERROR_CANNOT_MAKE_: return permission_denied;
+    case ERROR_CANTOPEN_: return io_error;
+    case ERROR_CANTREAD_: return io_error;
+    case ERROR_CANTWRITE_: return io_error;
+    case ERROR_CONNECTION_ABORTED_: return connection_aborted;
+    case ERROR_CURRENT_DIRECTORY_: return permission_denied;
+    case ERROR_DEV_NOT_EXIST_: return no_such_device;
+    case ERROR_DEVICE_IN_USE_: return device_or_resource_busy;
+    case ERROR_DIR_NOT_EMPTY_: return directory_not_empty;
+    case ERROR_DIRECTORY_: return invalid_argument; // WinError.h: "The directory name is invalid"
+    case ERROR_DISK_FULL_: return no_space_on_device;
+    case ERROR_FILE_EXISTS_: return file_exists;
+    case ERROR_FILE_NOT_FOUND_: return no_such_file_or_directory;
+    case ERROR_HANDLE_DISK_FULL_: return no_space_on_device;
+    case ERROR_INVALID_ACCESS_: return permission_denied;
+    case ERROR_INVALID_DRIVE_: return no_such_device;
+    case ERROR_INVALID_FUNCTION_: return function_not_supported;
+    case ERROR_INVALID_HANDLE_: return invalid_argument;
+    case ERROR_INVALID_NAME_: return no_such_file_or_directory;
+    case ERROR_INVALID_PARAMETER_: return invalid_argument;
+    case ERROR_LOCK_VIOLATION_: return no_lock_available;
+    case ERROR_LOCKED_: return no_lock_available;
+    case ERROR_NEGATIVE_SEEK_: return invalid_argument;
+    case ERROR_NOACCESS_: return permission_denied;
+    case ERROR_NOT_ENOUGH_MEMORY_: return not_enough_memory;
+    case ERROR_NOT_READY_: return resource_unavailable_try_again;
+    case ERROR_NOT_SAME_DEVICE_: return cross_device_link;
+    case ERROR_OPEN_FAILED_: return io_error;
+    case ERROR_OPEN_FILES_: return device_or_resource_busy;
+    case ERROR_OPERATION_ABORTED_: return operation_canceled;
+    case ERROR_OUTOFMEMORY_: return not_enough_memory;
+    case ERROR_PATH_NOT_FOUND_: return no_such_file_or_directory;
+    case ERROR_READ_FAULT_: return io_error;
+    case ERROR_REPARSE_TAG_INVALID_: return invalid_argument;
+    case ERROR_RETRY_: return resource_unavailable_try_again;
+    case ERROR_SEEK_: return io_error;
+    case ERROR_SHARING_VIOLATION_: return permission_denied;
+    case ERROR_NOT_SUPPORTED_: return not_supported; // WinError.h: "The request is not supported."
+    case ERROR_TOO_MANY_OPEN_FILES_: return too_many_files_open;
+    case ERROR_WRITE_FAULT_: return io_error;
+    case ERROR_WRITE_PROTECT_: return permission_denied;
+
+    case WSAEACCES_: return permission_denied;
+    case WSAEADDRINUSE_: return address_in_use;
+    case WSAEADDRNOTAVAIL_: return address_not_available;
+    case WSAEAFNOSUPPORT_: return address_family_not_supported;
+    case WSAEALREADY_: return connection_already_in_progress;
+    case WSAEBADF_: return bad_file_descriptor;
+    case WSAECONNABORTED_: return connection_aborted;
+    case WSAECONNREFUSED_: return connection_refused;
+    case WSAECONNRESET_: return connection_reset;
+    case WSAEDESTADDRREQ_: return destination_address_required;
+    case WSAEFAULT_: return bad_address;
+    case WSAEHOSTUNREACH_: return host_unreachable;
+    case WSAEINPROGRESS_: return operation_in_progress;
+    case WSAEINTR_: return interrupted;
+    case WSAEINVAL_: return invalid_argument;
+    case WSAEISCONN_: return already_connected;
+    case WSAEMFILE_: return too_many_files_open;
+    case WSAEMSGSIZE_: return message_size;
+    case WSAENAMETOOLONG_: return filename_too_long;
+    case WSAENETDOWN_: return network_down;
+    case WSAENETRESET_: return network_reset;
+    case WSAENETUNREACH_: return network_unreachable;
+    case WSAENOBUFS_: return no_buffer_space;
+    case WSAENOPROTOOPT_: return no_protocol_option;
+    case WSAENOTCONN_: return not_connected;
+    case WSAENOTSOCK_: return not_a_socket;
+    case WSAEOPNOTSUPP_: return operation_not_supported;
+    case WSAEPROTONOSUPPORT_: return protocol_not_supported;
+    case WSAEPROTOTYPE_: return wrong_protocol_type;
+    case WSAETIMEDOUT_: return timed_out;
+    case WSAEWOULDBLOCK_: return operation_would_block;
+
+    default: return -1;
+    }
+}
+
+} // namespace detail
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_SYSTEM_CATEGORY_CONDITION_WIN32_HPP_INCLUDED

include/boost/system/detail/system_category_impl.hpp

@@ -0,0 +1,61 @@
+#ifndef BOOST_SYSTEM_DETAIL_SYSTEM_CATEGORY_IMPL_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_SYSTEM_CATEGORY_IMPL_HPP_INCLUDED
+
+//  Copyright Beman Dawes 2006, 2007
+//  Copyright Christoper Kohlhoff 2007
+//  Copyright Peter Dimov 2017, 2018, 2020
+//
+//  Distributed under the Boost Software License, Version 1.0. (See accompanying
+//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+//  See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/system_category.hpp>
+#include <boost/system/detail/system_category_message.hpp>
+#include <boost/system/detail/error_condition.hpp>
+#include <boost/system/api_config.hpp>
+
+#if !defined(BOOST_POSIX_API) && !defined(BOOST_WINDOWS_API)
+#  error BOOST_POSIX_API or BOOST_WINDOWS_API must be defined
+#endif
+
+// system_error_category implementation
+
+#if defined(BOOST_WINDOWS_API)
+
+#include <boost/system/detail/system_category_condition_win32.hpp>
+
+inline boost::system::error_condition boost::system::detail::system_error_category::default_error_condition( int ev ) const BOOST_NOEXCEPT
+{
+    int e2 = system_category_condition_win32( ev );
+
+    if( e2 == -1 )
+    {
+        return error_condition( ev, *this );
+    }
+    else
+    {
+        return error_condition( boost::system::detail::generic_value_tag( e2 ) );
+    }
+}
+
+#else // #if defined(BOOST_WINDOWS_API)
+
+inline boost::system::error_condition boost::system::detail::system_error_category::default_error_condition( int ev ) const BOOST_NOEXCEPT
+{
+    return error_condition( boost::system::detail::generic_value_tag( ev ) );
+}
+
+#endif // #if defined(BOOST_WINDOWS_API)
+
+inline std::string boost::system::detail::system_error_category::message( int ev ) const
+{
+    return system_error_category_message( ev );
+}
+
+inline char const * boost::system::detail::system_error_category::message( int ev, char * buffer, std::size_t len ) const BOOST_NOEXCEPT
+{
+    return system_error_category_message( ev, buffer, len );
+}
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_SYSTEM_CATEGORY_IMPL_HPP_INCLUDED

include/boost/system/detail/system_category_message.hpp

@@ -0,0 +1,71 @@
+#ifndef BOOST_SYSTEM_DETAIL_SYSTEM_CATEGORY_MESSAGE_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_SYSTEM_CATEGORY_MESSAGE_HPP_INCLUDED
+
+// Implementation of system_error_category_message
+//
+// Copyright 2018, 2022 Peter Dimov
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/api_config.hpp>
+
+#if !defined(BOOST_POSIX_API) && !defined(BOOST_WINDOWS_API)
+#  error BOOST_POSIX_API or BOOST_WINDOWS_API must be defined
+#endif
+
+#if defined(BOOST_WINDOWS_API)
+
+#include <boost/system/detail/system_category_message_win32.hpp>
+
+namespace boost
+{
+namespace system
+{
+namespace detail
+{
+
+inline std::string system_error_category_message( int ev )
+{
+    return system_category_message_win32( ev );
+}
+
+inline char const * system_error_category_message( int ev, char * buffer, std::size_t len ) BOOST_NOEXCEPT
+{
+    return system_category_message_win32( ev, buffer, len );
+}
+
+} // namespace detail
+} // namespace system
+} // namespace boost
+
+#else // #if defined(BOOST_WINDOWS_API)
+
+#include <boost/system/detail/generic_category_message.hpp>
+
+namespace boost
+{
+namespace system
+{
+namespace detail
+{
+
+inline std::string system_error_category_message( int ev )
+{
+    return generic_error_category_message( ev );
+}
+
+inline char const * system_error_category_message( int ev, char * buffer, std::size_t len ) BOOST_NOEXCEPT
+{
+    return generic_error_category_message( ev, buffer, len );
+}
+
+} // namespace detail
+} // namespace system
+} // namespace boost
+
+#endif // #if defined(BOOST_WINDOWS_API)
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_SYSTEM_CATEGORY_MESSAGE_HPP_INCLUDED

include/boost/system/detail/system_category_message_win32.hpp

@@ -0,0 +1,211 @@
+#ifndef BOOST_SYSTEM_DETAIL_SYSTEM_CATEGORY_MESSAGE_WIN32_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_SYSTEM_CATEGORY_MESSAGE_WIN32_HPP_INCLUDED
+
+// Copyright Beman Dawes 2002, 2006
+// Copyright (c) Microsoft Corporation 2014
+// Copyright 2018, 2020 Peter Dimov
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/snprintf.hpp>
+#include <boost/winapi/error_handling.hpp>
+#include <boost/winapi/character_code_conversion.hpp>
+#include <boost/winapi/local_memory.hpp>
+#include <boost/config.hpp>
+#include <cstdio>
+
+//
+
+namespace boost
+{
+
+namespace system
+{
+
+namespace detail
+{
+
+inline char const * unknown_message_win32( int ev, char * buffer, std::size_t len )
+{
+    detail::snprintf( buffer, len, "Unknown error (%d)", ev );
+    return buffer;
+}
+
+inline boost::winapi::UINT_ message_cp_win32()
+{
+#if defined(BOOST_SYSTEM_USE_UTF8)
+
+    return boost::winapi::CP_UTF8_;
+
+#else
+
+    return boost::winapi::CP_ACP_;
+
+#endif
+}
+
+inline char const * system_category_message_win32( int ev, char * buffer, std::size_t len ) BOOST_NOEXCEPT
+{
+    if( len == 0 )
+    {
+        return buffer;
+    }
+
+    if( len == 1 )
+    {
+        buffer[0] = 0;
+        return buffer;
+    }
+
+    boost::winapi::UINT_ const code_page = message_cp_win32();
+
+    int r = 0;
+
+#if !defined(BOOST_NO_ANSI_APIS)
+
+    if( code_page == boost::winapi::CP_ACP_ )
+    {
+        using namespace boost::winapi;
+
+        DWORD_ retval = boost::winapi::FormatMessageA(
+            FORMAT_MESSAGE_FROM_SYSTEM_ | FORMAT_MESSAGE_IGNORE_INSERTS_,
+            NULL,
+            ev,
+            MAKELANGID_( LANG_NEUTRAL_, SUBLANG_DEFAULT_ ), // Default language
+            buffer,
+            static_cast<DWORD_>( len ),
+            NULL
+        );
+
+        r = static_cast<int>( retval );
+    }
+    else
+
+#endif
+
+    {
+        using namespace boost::winapi;
+
+        wchar_t * lpMsgBuf = 0;
+
+        DWORD_ retval = boost::winapi::FormatMessageW(
+            FORMAT_MESSAGE_ALLOCATE_BUFFER_ | FORMAT_MESSAGE_FROM_SYSTEM_ | FORMAT_MESSAGE_IGNORE_INSERTS_,
+            NULL,
+            ev,
+            MAKELANGID_( LANG_NEUTRAL_, SUBLANG_DEFAULT_ ), // Default language
+            (LPWSTR_) &lpMsgBuf,
+            0,
+            NULL
+        );
+
+        if( retval != 0 )
+        {
+            r = boost::winapi::WideCharToMultiByte( code_page, 0, lpMsgBuf, -1, buffer, static_cast<int>( len ), NULL, NULL );
+            boost::winapi::LocalFree( lpMsgBuf );
+            if ( r != 0 ) --r; // exclude null terminator
+        }
+    }
+
+    if( r == 0 )
+    {
+        return unknown_message_win32( ev, buffer, len );
+    }
+
+    while( r > 0 && ( buffer[ r-1 ] == '\n' || buffer[ r-1 ] == '\r' ) )
+    {
+        buffer[ --r ] = 0;
+    }
+
+    if( r > 0 && buffer[ r-1 ] == '.' )
+    {
+        buffer[ --r ] = 0;
+    }
+
+    return buffer;
+}
+
+struct local_free
+{
+    void * p_;
+
+    ~local_free()
+    {
+        boost::winapi::LocalFree( p_ );
+    }
+};
+
+inline std::string unknown_message_win32( int ev )
+{
+    char buffer[ 38 ];
+    return unknown_message_win32( ev, buffer, sizeof( buffer ) );
+}
+
+inline std::string system_category_message_win32( int ev )
+{
+    using namespace boost::winapi;
+
+    wchar_t * lpMsgBuf = 0;
+
+    DWORD_ retval = boost::winapi::FormatMessageW(
+        FORMAT_MESSAGE_ALLOCATE_BUFFER_ | FORMAT_MESSAGE_FROM_SYSTEM_ | FORMAT_MESSAGE_IGNORE_INSERTS_,
+        NULL,
+        ev,
+        MAKELANGID_( LANG_NEUTRAL_, SUBLANG_DEFAULT_ ), // Default language
+        (LPWSTR_) &lpMsgBuf,
+        0,
+        NULL
+    );
+
+    if( retval == 0 )
+    {
+        return unknown_message_win32( ev );
+    }
+
+    local_free lf_ = { lpMsgBuf };
+    (void)lf_;
+
+    UINT_ const code_page = message_cp_win32();
+
+    int r = boost::winapi::WideCharToMultiByte( code_page, 0, lpMsgBuf, -1, 0, 0, NULL, NULL );
+
+    if( r == 0 )
+    {
+        return unknown_message_win32( ev );
+    }
+
+    std::string buffer( r, char() );
+
+    r = boost::winapi::WideCharToMultiByte( code_page, 0, lpMsgBuf, -1, &buffer[0], r, NULL, NULL );
+
+    if( r == 0 )
+    {
+        return unknown_message_win32( ev );
+    }
+
+    --r; // exclude null terminator
+
+    while( r > 0 && ( buffer[ r-1 ] == '\n' || buffer[ r-1 ] == '\r' ) )
+    {
+        --r;
+    }
+
+    if( r > 0 && buffer[ r-1 ] == '.' )
+    {
+        --r;
+    }
+
+    buffer.resize( r );
+
+    return buffer;
+}
+
+} // namespace detail
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_SYSTEM_CATEGORY_MESSAGE_WIN32_HPP_INCLUDED

include/boost/system/detail/throws.hpp

@@ -0,0 +1,59 @@
+#ifndef BOOST_SYSTEM_DETAIL_THROWS_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_THROWS_HPP_INCLUDED
+
+//  Copyright Beman Dawes 2006, 2007
+//  Copyright Christoper Kohlhoff 2007
+//  Copyright Peter Dimov 2017, 2018
+//
+//  Distributed under the Boost Software License, Version 1.0. (See accompanying
+//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+//  See library home page at http://www.boost.org/libs/system
+
+namespace boost
+{
+
+namespace system
+{
+
+class error_code;
+
+} // namespace system
+
+// boost::throws()
+
+namespace detail
+{
+
+//  Misuse of the error_code object is turned into a noisy failure by
+//  poisoning the reference. This particular implementation doesn't
+//  produce warnings or errors from popular compilers, is very efficient
+//  (as determined by inspecting generated code), and does not suffer
+//  from order of initialization problems. In practice, it also seems
+//  cause user function error handling implementation errors to be detected
+//  very early in the development cycle.
+
+inline system::error_code* throws()
+{
+    // See github.com/boostorg/system/pull/12 by visigoth for why the return
+    // is poisoned with nonzero rather than (0). A test, test_throws_usage(),
+    // has been added to error_code_test.cpp, and as visigoth mentioned it
+    // fails on clang for release builds with a return of 0 but works fine
+    // with (1).
+    // Since the undefined behavior sanitizer (-fsanitize=undefined) does not
+    // allow a reference to be formed to the unaligned address of (1), we use
+    // (8) instead.
+
+    return reinterpret_cast<system::error_code*>(8);
+}
+
+} // namespace detail
+
+inline system::error_code& throws()
+{
+    return *detail::throws();
+}
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_THROWS_HPP_INCLUDED

include/boost/system/errc.hpp

@@ -0,0 +1,57 @@
+#ifndef BOOST_SYSTEM_ERRC_HPP_INCLUDED
+#define BOOST_SYSTEM_ERRC_HPP_INCLUDED
+
+// Copyright Beman Dawes 2006, 2007
+// Copyright Christoper Kohlhoff 2007
+// Copyright Peter Dimov 2017, 2018, 2020
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/errc.hpp>
+#include <boost/system/detail/error_code.hpp>
+#include <boost/system/detail/error_condition.hpp>
+#include <boost/system/detail/generic_category.hpp>
+#include <boost/system/detail/error_category_impl.hpp>
+#include <boost/system/detail/config.hpp>
+#include <boost/assert/source_location.hpp>
+#include <boost/config.hpp>
+
+namespace boost
+{
+
+namespace system
+{
+
+// make_* functions for errc::errc_t
+
+namespace errc
+{
+
+// explicit conversion:
+BOOST_SYSTEM_CONSTEXPR inline error_code make_error_code( errc_t e ) BOOST_NOEXCEPT
+{
+    return error_code( e, generic_category() );
+}
+
+// explicit conversion:
+inline error_code make_error_code( errc_t e, boost::source_location const * loc ) BOOST_NOEXCEPT
+{
+    return error_code( e, generic_category(), loc );
+}
+
+// implicit conversion:
+BOOST_SYSTEM_CONSTEXPR inline error_condition make_error_condition( errc_t e ) BOOST_NOEXCEPT
+{
+    return error_condition( e, generic_category() );
+}
+
+} // namespace errc
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_ERRC_HPP_INCLUDED

include/boost/system/error_category.hpp

@@ -0,0 +1,13 @@
+#ifndef BOOST_SYSTEM_ERROR_CATEGORY_HPP_INCLUDED
+#define BOOST_SYSTEM_ERROR_CATEGORY_HPP_INCLUDED
+
+// Copyright 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0
+// http://www.boost.org/LICENSE_1_0.txt
+//
+// See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/error_category.hpp>
+#include <boost/system/detail/error_category_impl.hpp>
+
+#endif // #ifndef BOOST_SYSTEM_ERROR_CATEGORY_HPP_INCLUDED

include/boost/system/error_code.hpp

@@ -1,513 +1,21 @@
-//  boost/system/error_code.hpp  ---------------------------------------------//
+#ifndef BOOST_SYSTEM_ERROR_CODE_HPP_INCLUDED
+#define BOOST_SYSTEM_ERROR_CODE_HPP_INCLUDED
 
 //  Copyright Beman Dawes 2006, 2007
 //  Copyright Christoper Kohlhoff 2007
-
+//  Copyright Peter Dimov 2017, 2018
+//
 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-
+//
 //  See library home page at http://www.boost.org/libs/system
 
-#ifndef BOOST_ERROR_CODE_HPP
-#define BOOST_ERROR_CODE_HPP
-
-#include <boost/system/config.hpp>
-#include <boost/cstdint.hpp>
-#include <boost/assert.hpp>
-#include <boost/operators.hpp>
-#include <boost/noncopyable.hpp>
-#include <boost/utility/enable_if.hpp>
-#include <ostream>
-#include <string>
-#include <stdexcept>
-#include <functional>
-
-// TODO: undef these macros if not already defined
-#include <boost/cerrno.hpp> 
-
-#if !defined(BOOST_POSIX_API) && !defined(BOOST_WINDOWS_API)
-#  error BOOST_POSIX_API or BOOST_WINDOWS_API must be defined
-#endif
-
-#include <boost/config/abi_prefix.hpp> // must be the last #include
-
-namespace boost
-{
-  namespace system
-  {
-
-    class error_code;
-    class error_condition;
-
-    //  "Concept" helpers  ---------------------------------------------------//
-
-    template< class T >
-    struct is_error_code_enum { static const bool value = false; };
-
-    template< class T >
-    struct is_error_condition_enum { static const bool value = false; };
-
-    //  generic error_conditions  --------------------------------------------//
-
-    namespace errc
-    {
-      enum errc_t
-      {
-        success = 0,
-        address_family_not_supported = EAFNOSUPPORT,
-        address_in_use = EADDRINUSE,
-        address_not_available = EADDRNOTAVAIL,
-        already_connected = EISCONN,
-        argument_list_too_long = E2BIG,
-        argument_out_of_domain = EDOM,
-        bad_address = EFAULT,
-        bad_file_descriptor = EBADF,
-        bad_message = EBADMSG,
-        broken_pipe = EPIPE,
-        connection_aborted = ECONNABORTED,
-        connection_already_in_progress = EALREADY,
-        connection_refused = ECONNREFUSED,
-        connection_reset = ECONNRESET,
-        cross_device_link = EXDEV,
-        destination_address_required = EDESTADDRREQ,
-        device_or_resource_busy = EBUSY,
-        directory_not_empty = ENOTEMPTY,
-        executable_format_error = ENOEXEC,
-        file_exists = EEXIST,
-        file_too_large = EFBIG,
-        filename_too_long = ENAMETOOLONG,
-        function_not_supported = ENOSYS,
-        host_unreachable = EHOSTUNREACH,
-        identifier_removed = EIDRM,
-        illegal_byte_sequence = EILSEQ,
-        inappropriate_io_control_operation = ENOTTY,
-        interrupted = EINTR,
-        invalid_argument = EINVAL,
-        invalid_seek = ESPIPE,
-        io_error = EIO,
-        is_a_directory = EISDIR,
-        message_size = EMSGSIZE,
-        network_down = ENETDOWN,
-        network_reset = ENETRESET,
-        network_unreachable = ENETUNREACH,
-        no_buffer_space = ENOBUFS,
-        no_child_process = ECHILD,
-        no_link = ENOLINK,
-        no_lock_available = ENOLCK,
-        no_message_available = ENODATA,
-        no_message = ENOMSG,
-        no_protocol_option = ENOPROTOOPT,
-        no_space_on_device = ENOSPC,
-        no_stream_resources = ENOSR,
-        no_such_device_or_address = ENXIO,
-        no_such_device = ENODEV,
-        no_such_file_or_directory = ENOENT,
-        no_such_process = ESRCH,
-        not_a_directory = ENOTDIR,
-        not_a_socket = ENOTSOCK,
-        not_a_stream = ENOSTR,
-        not_connected = ENOTCONN,
-        not_enough_memory = ENOMEM,
-        not_supported = ENOTSUP,
-        operation_canceled = ECANCELED,
-        operation_in_progress = EINPROGRESS,
-        operation_not_permitted = EPERM,
-        operation_not_supported = EOPNOTSUPP,
-        operation_would_block = EWOULDBLOCK,
-        owner_dead = EOWNERDEAD,
-        permission_denied = EACCES,
-        protocol_error = EPROTO,
-        protocol_not_supported = EPROTONOSUPPORT,
-        read_only_file_system = EROFS,
-        resource_deadlock_would_occur = EDEADLK,
-        resource_unavailable_try_again = EAGAIN,
-        result_out_of_range = ERANGE,
-        state_not_recoverable = ENOTRECOVERABLE,
-        stream_timeout = ETIME,
-        text_file_busy = ETXTBSY,
-        timed_out = ETIMEDOUT,
-        too_many_files_open_in_system = ENFILE,
-        too_many_files_open = EMFILE,
-        too_many_links = EMLINK,
-        too_many_synbolic_link_levels = ELOOP,
-        value_too_large = EOVERFLOW,
-        wrong_protocol_type = EPROTOTYPE
-      };
-
-    } // namespace errc
-
-# ifndef BOOST_SYSTEM_NO_DEPRECATED
-    namespace posix = errc;
-    namespace posix_error = errc;
-# endif
-
-    template<> struct is_error_condition_enum<errc::errc_t>
-      { static const bool value = true; };
-
-
-    //  ----------------------------------------------------------------------//
-
-    //  Operating system specific interfaces  --------------------------------//
-
-
-    //  The interface is divided into general and system-specific portions to
-    //  meet these requirements:
-    //
-    //  * Code calling an operating system API can create an error_code with
-    //    a single category (system_category), even for POSIX-like operating
-    //    systems that return some POSIX errno values and some native errno
-    //    values. This code should not have to pay the cost of distinguishing
-    //    between categories, since it is not yet known if that is needed.
-    //
-    //  * Users wishing to write system-specific code should be given enums for
-    //    at least the common error cases.
-    //
-    //  * System specific code should fail at compile time if moved to another
-    //    operating system.
-
-    //  The system specific portions of the interface are located in headers
-    //  with names reflecting the operating system. For example,
-    //
-    //       <boost/system/cygwin_error.hpp>
-    //       <boost/system/linux_error.hpp>
-    //       <boost/system/windows_error.hpp>
-    //
-    //  These headers are effectively empty for compiles on operating systems
-    //  where they are not applicable.
-
-    //  ----------------------------------------------------------------------//
-
-    //  class error_category  ------------------------------------------------//
-
-    class error_category : public noncopyable
-    {
-    public:
-      virtual ~error_category(){}
-
-      virtual const char *     name() const = 0;
-      virtual std::string      message( int ev ) const = 0;
-      virtual error_condition  default_error_condition( int ev ) const;
-      virtual bool             equivalent( int code, 
-                                           const error_condition & condition ) const;
-      virtual bool             equivalent( const error_code & code,
-                                           int condition ) const;
-
-      bool operator==(const error_category & rhs) const { return this == &rhs; }
-      bool operator!=(const error_category & rhs) const { return this != &rhs; }
-      bool operator<( const error_category & rhs ) const
-      {
-        return std::less<const error_category*>()( this, &rhs );
-      }
-    };
-
-    //  predefined error categories  -----------------------------------------//
-
-    BOOST_SYSTEM_DECL const error_category &  get_system_category();
-    BOOST_SYSTEM_DECL const error_category &  get_generic_category();
-
-    static const error_category &  system_category = get_system_category();
-    static const error_category &  generic_category = get_generic_category();
-    
-# ifndef BOOST_SYSTEM_NO_DEPRECATED
-    //  deprecated synonyms
-    inline const error_category &  get_posix_category() { return get_generic_category(); }
-    static const error_category &  posix_category = get_generic_category();
-    static const error_category &  errno_ecat     = get_generic_category();
-    static const error_category &  native_ecat    = get_system_category();
-# endif
-
-    //  class error_condition  -----------------------------------------------//
-
-    //  error_conditions are portable, error_codes are system or library specific
-
-    class error_condition
-    {
-    public:
-
-      // constructors:
-      error_condition() : m_val(0), m_cat(&get_generic_category()) {}
-      error_condition( int val, const error_category & cat ) : m_val(val), m_cat(&cat) {}
-
-      template <class ErrorConditionEnum>
-        error_condition(ErrorConditionEnum e,
-          typename boost::enable_if<is_error_condition_enum<ErrorConditionEnum> >::type* = 0)
-      {
-        *this = make_error_condition(e);
-      }
-
-      // modifiers:
-
-      void assign( int val, const error_category & cat )
-      { 
-        m_val = val;
-        m_cat = &cat;
-      }
-                                             
-      template<typename ErrorConditionEnum>
-        typename boost::enable_if<is_error_condition_enum<ErrorConditionEnum>, error_condition>::type &
-          operator=( ErrorConditionEnum val )
-      { 
-        *this = make_error_condition(val);
-        return *this;
-      }
-
-      void clear()
-      {
-        m_val = 0;
-        m_cat = &get_generic_category();
-      }
-
-      // observers:
-      int                     value() const    { return m_val; }
-      const error_category &  category() const { return *m_cat; }
-      std::string             message() const  { return m_cat->message(value()); }
-
-      typedef void (*unspecified_bool_type)();
-      static void unspecified_bool_true() {}
-
-      operator unspecified_bool_type() const  // true if error
-      { 
-        return m_val == 0 ? 0 : unspecified_bool_true;
-      }
-
-      bool operator!() const  // true if no error
-      {
-        return m_val == 0;
-      }
-
-      // relationals:
-      //  the more symmetrical non-member syntax allows enum
-      //  conversions work for both rhs and lhs.
-      inline friend bool operator==( const error_condition & lhs,
-                                     const error_condition & rhs )
-      {
-        return lhs.m_cat == rhs.m_cat && lhs.m_val == rhs.m_val;
-      }                  
-
-      inline friend bool operator<( const error_condition & lhs,
-                                    const error_condition & rhs )
-        //  the more symmetrical non-member syntax allows enum
-        //  conversions work for both rhs and lhs.
-      {
-        return lhs.m_cat < rhs.m_cat
-          || (lhs.m_cat == rhs.m_cat && lhs.m_val < rhs.m_val);
-      }
-
-    private:
-      int                     m_val;
-      const error_category *  m_cat;
-
-    };
-
-    //  class error_code  ----------------------------------------------------//
-
-    //  We want error_code to be a value type that can be copied without slicing
-    //  and without requiring heap allocation, but we also want it to have
-    //  polymorphic behavior based on the error category. This is achieved by
-    //  abstract base class error_category supplying the polymorphic behavior,
-    //  and error_code containing a pointer to an object of a type derived
-    //  from error_category.
-    class error_code
-    {
-    public:
-
-      // constructors:
-      error_code() : m_val(0), m_cat(&get_system_category()) {}
-      error_code( int val, const error_category & cat ) : m_val(val), m_cat(&cat) {}
-
-      template <class ErrorCodeEnum>
-        error_code(ErrorCodeEnum e,
-          typename boost::enable_if<is_error_code_enum<ErrorCodeEnum> >::type* = 0)
-      {
-        *this = make_error_code(e);
-      }
-
-      // modifiers:
-      void assign( int val, const error_category & cat )
-      { 
-        m_val = val;
-        m_cat = &cat;
-      }
-                                             
-      template<typename ErrorCodeEnum>
-        typename boost::enable_if<is_error_code_enum<ErrorCodeEnum>, error_code>::type &
-          operator=( ErrorCodeEnum val )
-      { 
-        *this = make_error_code(val);
-        return *this;
-      }
-
-      void clear()
-      {
-        m_val = 0;
-        m_cat = &get_system_category();
-      }
-
-      // observers:
-      int                     value() const    { return m_val; }
-      const error_category &  category() const { return *m_cat; }
-      error_condition         default_error_condition() const  { return m_cat->default_error_condition(value()); }
-      std::string             message() const  { return m_cat->message(value()); }
-
-      typedef void (*unspecified_bool_type)();
-      static void unspecified_bool_true() {}
-
-      operator unspecified_bool_type() const  // true if error
-      { 
-        return m_val == 0 ? 0 : unspecified_bool_true;
-      }
-
-      bool operator!() const  // true if no error
-      {
-        return m_val == 0;
-      }
-
-      // relationals:
-      inline friend bool operator==( const error_code & lhs,
-                                     const error_code & rhs )
-        //  the more symmetrical non-member syntax allows enum
-        //  conversions work for both rhs and lhs.
-      {
-        return lhs.m_cat == rhs.m_cat && lhs.m_val == rhs.m_val;
-      }
-
-      inline friend bool operator<( const error_code & lhs,
-                                    const error_code & rhs )
-        //  the more symmetrical non-member syntax allows enum
-        //  conversions work for both rhs and lhs.
-      {
-        return lhs.m_cat < rhs.m_cat
-          || (lhs.m_cat == rhs.m_cat && lhs.m_val < rhs.m_val);
-      }
-                  
-      private:
-      int                     m_val;
-      const error_category *  m_cat;
-
-    };
-
-    //  predefined error_code object used as "throw on error" tag
-# ifndef BOOST_SYSTEM_NO_DEPRECATED
-    BOOST_SYSTEM_DECL extern error_code throws;
-# endif
-
-    //  Moving from a "throws" object to a "throws" function without breaking
-    //  existing code is a bit of a problem. The workaround is to place the
-    //  "throws" function in namespace boost rather than namespace boost::system.
-
-  }  // namespace system
-
-  namespace detail { inline system::error_code * throws() { return 0; } }
-    //  Misuse of the error_code object is turned into a noisy failure by
-    //  poisoning the reference. This particular implementation doesn't
-    //  produce warnings or errors from popular compilers, is very efficient
-    //  (as determined by inspecting generated code), and does not suffer
-    //  from order of initialization problems. In practice, it also seems
-    //  cause user function error handling implementation errors to be detected
-    //  very early in the development cycle.
-
-  inline system::error_code & throws()
-    { return *detail::throws(); }
-
-  namespace system
-  {
-    //  non-member functions  ------------------------------------------------//
-
-    inline bool operator!=( const error_code & lhs,
-                            const error_code & rhs )
-    {
-      return !(lhs == rhs);
-    }
-
-    inline bool operator!=( const error_condition & lhs,
-                            const error_condition & rhs )
-    {
-      return !(lhs == rhs);
-    }
-
-    inline bool operator==( const error_code & code,
-                            const error_condition & condition )
-    {
-      return code.category().equivalent( code.value(), condition )
-        || condition.category().equivalent( code, condition.value() );
-    }
-                
-    inline bool operator!=( const error_code & lhs,
-                            const error_condition & rhs )
-    {
-      return !(lhs == rhs);
-    }
-                
-    inline bool operator==( const error_condition & condition,
-                            const error_code & code )
-    {
-      return condition.category().equivalent( code, condition.value() )
-        || code.category().equivalent( code.value(), condition );
-    }
-                
-    inline bool operator!=( const error_condition & lhs,
-                            const error_code & rhs )
-    {
-      return !(lhs == rhs);
-    }
-                  
-    // TODO: both of these may move elsewhere, but the LWG hasn't spoken yet.
-
-    template <class charT, class traits>
-    inline std::basic_ostream<charT,traits>&
-      operator<< (std::basic_ostream<charT,traits>& os, error_code ec)
-    {
-      os << ec.category().name() << ':' << ec.value();
-      return os;
-    }
-
-    inline std::size_t hash_value( const error_code & ec )
-    {
-      return static_cast<std::size_t>(ec.value())
-        + reinterpret_cast<std::size_t>(&ec.category());
-    }
-
-    //  make_* functions for errc::errc_t  -----------------------------//
-
-    namespace errc
-    {
-      //  explicit conversion:
-      inline error_code make_error_code( errc_t e )
-        { return error_code( e, get_generic_category() ); }
-
-      //  implicit conversion:
-      inline error_condition make_error_condition( errc_t e )
-        { return error_condition( e, get_generic_category() ); }
-    }
-
-    //  error_category default implementation  -------------------------------//
-
-    inline error_condition error_category::default_error_condition( int ev ) const
-    { 
-      return error_condition( ev, *this );
-    }
-
-    inline bool error_category::equivalent( int code,
-      const error_condition & condition ) const
-    {
-      return default_error_condition( code ) == condition;
-    }
-
-    inline bool error_category::equivalent( const error_code & code,
-      int condition ) const
-    {
-      return *this == code.category() && code.value() == condition;
-    }
-
-  } // namespace system
-} // namespace boost
-
-#include <boost/config/abi_suffix.hpp> // pops abi_prefix.hpp pragmas
-
-# ifdef BOOST_ERROR_CODE_HEADER_ONLY
-#   include <boost/../libs/system/src/error_code.cpp>
-# endif
-
-#endif // BOOST_ERROR_CODE_HPP
-
-
+#include <boost/system/detail/error_code.hpp>
+#include <boost/system/error_category.hpp>
+#include <boost/system/error_condition.hpp>
+#include <boost/system/errc.hpp>
+#include <boost/system/generic_category.hpp>
+#include <boost/system/system_category.hpp>
+#include <boost/system/detail/throws.hpp>
+
+#endif // BOOST_SYSTEM_ERROR_CODE_HPP_INCLUDED

include/boost/system/error_condition.hpp

@@ -0,0 +1,13 @@
+#ifndef BOOST_SYSTEM_ERROR_CONDITION_HPP_INCLUDED
+#define BOOST_SYSTEM_ERROR_CONDITION_HPP_INCLUDED
+
+// Copyright 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0
+// http://www.boost.org/LICENSE_1_0.txt
+//
+// See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/error_condition.hpp>
+#include <boost/system/detail/error_category_impl.hpp>
+
+#endif // #ifndef BOOST_SYSTEM_ERROR_CONDITION_HPP_INCLUDED

include/boost/system/generic_category.hpp

@@ -0,0 +1,13 @@
+#ifndef BOOST_SYSTEM_GENERIC_CATEGORY_HPP_INCLUDED
+#define BOOST_SYSTEM_GENERIC_CATEGORY_HPP_INCLUDED
+
+// Copyright 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0
+// http://www.boost.org/LICENSE_1_0.txt
+//
+// See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/generic_category.hpp>
+#include <boost/system/detail/error_category_impl.hpp>
+
+#endif // #ifndef BOOST_SYSTEM_GENERIC_CATEGORY_HPP_INCLUDED

include/boost/system/is_error_code_enum.hpp

@@ -0,0 +1,30 @@
+#ifndef BOOST_SYSTEM_IS_ERROR_CODE_ENUM_HPP_INCLUDED
+#define BOOST_SYSTEM_IS_ERROR_CODE_ENUM_HPP_INCLUDED
+
+//  Copyright Beman Dawes 2006, 2007
+//  Copyright Christoper Kohlhoff 2007
+//  Copyright Peter Dimov 2017, 2018
+//
+//  Distributed under the Boost Software License, Version 1.0. (See accompanying
+//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+//  See library home page at http://www.boost.org/libs/system
+
+namespace boost
+{
+
+namespace system
+{
+
+class error_code;
+
+template<class T> struct is_error_code_enum
+{
+    static const bool value = false;
+};
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_IS_ERROR_CODE_ENUM_HPP_INCLUDED

include/boost/system/is_error_condition_enum.hpp

@@ -0,0 +1,30 @@
+#ifndef BOOST_SYSTEM_IS_ERROR_CONDITION_ENUM_HPP_INCLUDED
+#define BOOST_SYSTEM_IS_ERROR_CONDITION_ENUM_HPP_INCLUDED
+
+//  Copyright Beman Dawes 2006, 2007
+//  Copyright Christoper Kohlhoff 2007
+//  Copyright Peter Dimov 2017, 2018
+//
+//  Distributed under the Boost Software License, Version 1.0. (See accompanying
+//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+//  See library home page at http://www.boost.org/libs/system
+
+namespace boost
+{
+
+namespace system
+{
+
+class error_condition;
+
+template<class T> struct is_error_condition_enum
+{
+    static const bool value = false;
+};
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_IS_ERROR_CONDITION_ENUM_HPP_INCLUDED

include/boost/system/linux_error.hpp

@@ -7,8 +7,8 @@
 
 //  See library home page at http://www.boost.org/libs/system
 
-#ifndef BOOST_LINUX_ERROR_HPP
-#define BOOST_LINUX_ERROR_HPP
+#ifndef BOOST_SYSTEM_LINUX_ERROR_HPP
+#define BOOST_SYSTEM_LINUX_ERROR_HPP
 
 //  This header is effectively empty for compiles on operating systems where
 //  it is not applicable.
@@ -23,7 +23,7 @@ namespace boost
   {
     //  To construct an error_code after a API error:
     //
-    //      error_code( errno, system_category )
+    //      error_code( errno, system_category() )
 
     //  User code should use the portable "posix" enums for POSIX errors; this
     //  allows such code to be portable to non-POSIX systems. For the non-POSIX
@@ -89,7 +89,7 @@ namespace boost
       };
     }  // namespace linux_error
 
-# ifndef BOOST_SYSTEM_NO_DEPRECATED
+# ifdef BOOST_SYSTEM_ENABLE_DEPRECATED
     namespace Linux = linux_error;
 # endif
 
@@ -99,7 +99,7 @@ namespace boost
     namespace linux_error
     {
       inline error_code make_error_code( linux_errno e )
-        { return error_code( e, get_system_category() ); }
+        { return error_code( e, system_category() ); }
     }
 
   }  // namespace system
@@ -107,4 +107,4 @@ namespace boost
 
 #endif  // Linux
 
-#endif  // BOOST_LINUX_ERROR_HPP
+#endif  // BOOST_SYSTEM_LINUX_ERROR_HPP

include/boost/system/result.hpp

@@ -0,0 +1,604 @@
+#ifndef BOOST_SYSTEM_RESULT_HPP_INCLUDED
+#define BOOST_SYSTEM_RESULT_HPP_INCLUDED
+
+// Copyright 2017, 2021, 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/errc.hpp>
+#include <boost/system/system_error.hpp>
+#include <boost/system/detail/error_code.hpp>
+#include <boost/system/detail/error_category_impl.hpp>
+#include <boost/variant2/variant.hpp>
+#include <boost/throw_exception.hpp>
+#include <boost/assert/source_location.hpp>
+#include <boost/assert.hpp>
+#include <boost/config.hpp>
+#include <type_traits>
+#include <utility>
+#include <iosfwd>
+#include <system_error>
+#include <exception>
+
+//
+
+namespace boost
+{
+namespace system
+{
+
+// throw_exception_from_error
+
+#if defined(__GNUC__) && __GNUC__ >= 7 && __GNUC__ <= 8
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wattributes"
+#endif
+
+BOOST_NORETURN BOOST_NOINLINE inline void throw_exception_from_error( error_code const & e, boost::source_location const& loc )
+{
+    boost::throw_with_location( system_error( e ), loc );
+}
+
+BOOST_NORETURN BOOST_NOINLINE inline void throw_exception_from_error( errc::errc_t const & e, boost::source_location const& loc )
+{
+    boost::throw_with_location( system_error( make_error_code( e ) ), loc );
+}
+
+BOOST_NORETURN BOOST_NOINLINE inline void throw_exception_from_error( std::error_code const & e, boost::source_location const& loc )
+{
+    boost::throw_with_location( std::system_error( e ), loc );
+}
+
+BOOST_NORETURN BOOST_NOINLINE inline void throw_exception_from_error( std::errc const & e, boost::source_location const& loc )
+{
+    boost::throw_with_location( std::system_error( make_error_code( e ) ), loc );
+}
+
+BOOST_NORETURN BOOST_NOINLINE inline void throw_exception_from_error( std::exception_ptr const & p, boost::source_location const& loc )
+{
+    if( p )
+    {
+        std::rethrow_exception( p );
+    }
+    else
+    {
+        boost::throw_with_location( std::bad_exception(), loc );
+    }
+}
+
+#if defined(__GNUC__) && __GNUC__ >= 7 && __GNUC__ <= 8
+# pragma GCC diagnostic pop
+#endif
+
+// in_place_*
+
+using in_place_value_t = variant2::in_place_index_t<0>;
+constexpr in_place_value_t in_place_value{};
+
+using in_place_error_t = variant2::in_place_index_t<1>;
+constexpr in_place_error_t in_place_error{};
+
+namespace detail
+{
+
+template<class T> using remove_cvref = typename std::remove_cv< typename std::remove_reference<T>::type >::type;
+
+template<class... T> using is_errc_t = std::is_same<mp11::mp_list<remove_cvref<T>...>, mp11::mp_list<errc::errc_t>>;
+
+} // namespace detail
+
+// result
+
+template<class T, class E = error_code> class result
+{
+private:
+
+    variant2::variant<T, E> v_;
+
+public:
+
+    // constructors
+
+    // default
+    template<class En2 = void, class En = typename std::enable_if<
+        std::is_void<En2>::value &&
+        std::is_default_constructible<T>::value
+        >::type>
+    constexpr result()
+        noexcept( std::is_nothrow_default_constructible<T>::value )
+        : v_( in_place_value )
+    {
+    }
+
+    // implicit, value
+    template<class A = T, typename std::enable_if<
+        std::is_convertible<A, T>::value &&
+        !(detail::is_errc_t<A>::value && std::is_arithmetic<T>::value) &&
+        !std::is_constructible<E, A>::value, int>::type = 0>
+    constexpr result( A&& a )
+        noexcept( std::is_nothrow_constructible<T, A>::value )
+        : v_( in_place_value, std::forward<A>(a) )
+    {
+    }
+
+    // implicit, error
+    template<class A = E, class = void, typename std::enable_if<
+        std::is_convertible<A, E>::value &&
+        !std::is_constructible<T, A>::value, int>::type = 0>
+    constexpr result( A&& a )
+        noexcept( std::is_nothrow_constructible<E, A>::value )
+        : v_( in_place_error, std::forward<A>(a) )
+    {
+    }
+
+    // explicit, value
+    template<class... A, class En = typename std::enable_if<
+        std::is_constructible<T, A...>::value &&
+        !(detail::is_errc_t<A...>::value && std::is_arithmetic<T>::value) &&
+        !std::is_constructible<E, A...>::value
+        >::type>
+    explicit constexpr result( A&&... a )
+        noexcept( std::is_nothrow_constructible<T, A...>::value )
+        : v_( in_place_value, std::forward<A>(a)... )
+    {
+    }
+
+    // explicit, error
+    template<class... A, class En2 = void, class En = typename std::enable_if<
+        !std::is_constructible<T, A...>::value &&
+        std::is_constructible<E, A...>::value
+        >::type>
+    explicit constexpr result( A&&... a )
+        noexcept( std::is_nothrow_constructible<E, A...>::value )
+        : v_( in_place_error, std::forward<A>(a)... )
+    {
+    }
+
+    // tagged, value
+    template<class... A, class En = typename std::enable_if<
+        std::is_constructible<T, A...>::value
+        >::type>
+    constexpr result( in_place_value_t, A&&... a )
+        noexcept( std::is_nothrow_constructible<T, A...>::value )
+        : v_( in_place_value, std::forward<A>(a)... )
+    {
+    }
+
+    // tagged, error
+    template<class... A, class En = typename std::enable_if<
+        std::is_constructible<E, A...>::value
+        >::type>
+    constexpr result( in_place_error_t, A&&... a )
+        noexcept( std::is_nothrow_constructible<E, A...>::value )
+        : v_( in_place_error, std::forward<A>(a)... )
+    {
+    }
+
+    // converting
+    template<class T2, class E2, class En = typename std::enable_if<
+        std::is_convertible<T2, T>::value &&
+        std::is_convertible<E2, E>::value
+        >::type>
+    BOOST_CXX14_CONSTEXPR result( result<T2, E2> const& r2 )
+        noexcept(
+            std::is_nothrow_constructible<T, T2 const&>::value &&
+            std::is_nothrow_constructible<E, E2>::value &&
+            std::is_nothrow_default_constructible<E2>::value &&
+            std::is_nothrow_copy_constructible<E2>::value )
+        : v_( in_place_error, r2.error() )
+    {
+        if( r2 )
+        {
+            v_.template emplace<0>( *r2 );
+        }
+    }
+
+    template<class T2, class E2, class En = typename std::enable_if<
+        std::is_convertible<T2, T>::value &&
+        std::is_convertible<E2, E>::value
+        >::type>
+    BOOST_CXX14_CONSTEXPR result( result<T2, E2>&& r2 )
+        noexcept(
+            std::is_nothrow_constructible<T, T2&&>::value &&
+            std::is_nothrow_constructible<E, E2>::value &&
+            std::is_nothrow_default_constructible<E2>::value &&
+            std::is_nothrow_copy_constructible<E2>::value )
+        : v_( in_place_error, r2.error() )
+    {
+        if( r2 )
+        {
+            v_.template emplace<0>( std::move( *r2 ) );
+        }
+    }
+
+    // queries
+
+    constexpr bool has_value() const noexcept
+    {
+        return v_.index() == 0;
+    }
+
+    constexpr bool has_error() const noexcept
+    {
+        return v_.index() != 0;
+    }
+
+    constexpr explicit operator bool() const noexcept
+    {
+        return v_.index() == 0;
+    }
+
+    // checked value access
+#if defined( BOOST_NO_CXX11_REF_QUALIFIERS )
+
+    BOOST_CXX14_CONSTEXPR T value( boost::source_location const& loc = BOOST_CURRENT_LOCATION ) const
+    {
+        if( has_value() )
+        {
+            return variant2::unsafe_get<0>( v_ );
+        }
+        else
+        {
+            throw_exception_from_error( variant2::unsafe_get<1>( v_ ), loc );
+        }
+    }
+
+#else
+
+    BOOST_CXX14_CONSTEXPR T& value( boost::source_location const& loc = BOOST_CURRENT_LOCATION ) &
+    {
+        if( has_value() )
+        {
+            return variant2::unsafe_get<0>( v_ );
+        }
+        else
+        {
+            throw_exception_from_error( variant2::unsafe_get<1>( v_ ), loc );
+        }
+    }
+
+    BOOST_CXX14_CONSTEXPR T const& value( boost::source_location const& loc = BOOST_CURRENT_LOCATION ) const&
+    {
+        if( has_value() )
+        {
+            return variant2::unsafe_get<0>( v_ );
+        }
+        else
+        {
+            throw_exception_from_error( variant2::unsafe_get<1>( v_ ), loc );
+        }
+    }
+
+    template<class U = T>
+        BOOST_CXX14_CONSTEXPR
+        typename std::enable_if<std::is_move_constructible<U>::value, T>::type
+        value( boost::source_location const& loc = BOOST_CURRENT_LOCATION ) &&
+    {
+        return std::move( value( loc ) );
+    }
+
+    template<class U = T>
+        BOOST_CXX14_CONSTEXPR
+        typename std::enable_if<!std::is_move_constructible<U>::value, T&&>::type
+        value( boost::source_location const& loc = BOOST_CURRENT_LOCATION ) &&
+    {
+        return std::move( value( loc ) );
+    }
+
+    template<class U = T>
+        BOOST_CXX14_CONSTEXPR
+        typename std::enable_if<std::is_move_constructible<U>::value, T>::type
+        value() const && = delete;
+
+    template<class U = T>
+        BOOST_CXX14_CONSTEXPR
+        typename std::enable_if<!std::is_move_constructible<U>::value, T const&&>::type
+        value( boost::source_location const& loc = BOOST_CURRENT_LOCATION ) const &&
+    {
+        return std::move( value( loc ) );
+    }
+
+#endif
+
+    // unchecked value access
+
+    BOOST_CXX14_CONSTEXPR T* operator->() noexcept
+    {
+        return variant2::get_if<0>( &v_ );
+    }
+
+    BOOST_CXX14_CONSTEXPR T const* operator->() const noexcept
+    {
+        return variant2::get_if<0>( &v_ );
+    }
+
+#if defined( BOOST_NO_CXX11_REF_QUALIFIERS )
+
+    BOOST_CXX14_CONSTEXPR T& operator*() noexcept
+    {
+        T* p = operator->();
+
+        BOOST_ASSERT( p != 0 );
+
+        return *p;
+    }
+
+    BOOST_CXX14_CONSTEXPR T const& operator*() const noexcept
+    {
+        T const* p = operator->();
+
+        BOOST_ASSERT( p != 0 );
+
+        return *p;
+    }
+
+#else
+
+    BOOST_CXX14_CONSTEXPR T& operator*() & noexcept
+    {
+        T* p = operator->();
+
+        BOOST_ASSERT( p != 0 );
+
+        return *p;
+    }
+
+    BOOST_CXX14_CONSTEXPR T const& operator*() const & noexcept
+    {
+        T const* p = operator->();
+
+        BOOST_ASSERT( p != 0 );
+
+        return *p;
+    }
+
+    template<class U = T>
+        BOOST_CXX14_CONSTEXPR
+        typename std::enable_if<std::is_move_constructible<U>::value, T>::type
+        operator*() && noexcept(std::is_nothrow_move_constructible<T>::value)
+    {
+        return std::move(**this);
+    }
+
+    template<class U = T>
+        BOOST_CXX14_CONSTEXPR
+        typename std::enable_if<!std::is_move_constructible<U>::value, T&&>::type
+        operator*() && noexcept
+    {
+        return std::move(**this);
+    }
+
+    template<class U = T>
+        BOOST_CXX14_CONSTEXPR
+        typename std::enable_if<std::is_move_constructible<U>::value, T>::type
+        operator*() const && noexcept = delete;
+
+    template<class U = T>
+        BOOST_CXX14_CONSTEXPR
+        typename std::enable_if<!std::is_move_constructible<U>::value, T const&&>::type
+        operator*() const && noexcept
+    {
+        return std::move(**this);
+    }
+
+#endif
+
+    // error access
+
+    constexpr E error() const
+        noexcept( std::is_nothrow_default_constructible<E>::value && std::is_nothrow_copy_constructible<E>::value )
+    {
+        return has_error()? variant2::unsafe_get<1>( v_ ): E();
+    }
+
+    // swap
+
+    BOOST_CXX14_CONSTEXPR void swap( result& r )
+        noexcept( noexcept( v_.swap( r.v_ ) ) )
+    {
+        v_.swap( r.v_ );
+    }
+
+    friend BOOST_CXX14_CONSTEXPR void swap( result & r1, result & r2 )
+        noexcept( noexcept( r1.swap( r2 ) ) )
+    {
+        r1.swap( r2 );
+    }
+
+    // equality
+
+    friend constexpr bool operator==( result const & r1, result const & r2 )
+        noexcept( noexcept( r1.v_ == r2.v_ ) )
+    {
+        return r1.v_ == r2.v_;
+    }
+
+    friend constexpr bool operator!=( result const & r1, result const & r2 )
+        noexcept( noexcept( !( r1 == r2 ) ) )
+    {
+        return !( r1 == r2 );
+    }
+};
+
+template<class Ch, class Tr, class T, class E> std::basic_ostream<Ch, Tr>& operator<<( std::basic_ostream<Ch, Tr>& os, result<T, E> const & r )
+{
+    if( r.has_value() )
+    {
+        os << "value:" << *r;
+    }
+    else
+    {
+        os << "error:" << r.error();
+    }
+
+    return os;
+}
+
+// result<void>
+
+template<class E> class result<void, E>
+{
+private:
+
+    variant2::variant<variant2::monostate, E> v_;
+
+public:
+
+    // constructors
+
+    // default
+    constexpr result() noexcept
+        : v_( in_place_value )
+    {
+    }
+
+    // explicit, error
+    template<class A, class En = typename std::enable_if<
+        std::is_constructible<E, A>::value &&
+        !std::is_convertible<A, E>::value
+        >::type>
+    explicit constexpr result( A&& a )
+        noexcept( std::is_nothrow_constructible<E, A>::value )
+        : v_( in_place_error, std::forward<A>(a) )
+    {
+    }
+
+    // implicit, error
+    template<class A, class En2 = void, class En = typename std::enable_if<
+        std::is_convertible<A, E>::value
+        >::type>
+    constexpr result( A&& a )
+        noexcept( std::is_nothrow_constructible<E, A>::value )
+        : v_( in_place_error, std::forward<A>(a) )
+    {
+    }
+
+    // more than one arg, error
+    template<class... A, class En2 = void, class En3 = void, class En = typename std::enable_if<
+        std::is_constructible<E, A...>::value &&
+        sizeof...(A) >= 2
+        >::type>
+    constexpr result( A&&... a )
+        noexcept( std::is_nothrow_constructible<E, A...>::value )
+        : v_( in_place_error, std::forward<A>(a)... )
+    {
+    }
+
+    // tagged, value
+    constexpr result( in_place_value_t ) noexcept
+        : v_( in_place_value )
+    {
+    }
+
+    // tagged, error
+    template<class... A, class En = typename std::enable_if<
+        std::is_constructible<E, A...>::value
+        >::type>
+    constexpr result( in_place_error_t, A&&... a )
+        noexcept( std::is_nothrow_constructible<E, A...>::value )
+        : v_( in_place_error, std::forward<A>(a)... )
+    {
+    }
+
+    // queries
+
+    constexpr bool has_value() const noexcept
+    {
+        return v_.index() == 0;
+    }
+
+    constexpr bool has_error() const noexcept
+    {
+        return v_.index() != 0;
+    }
+
+    constexpr explicit operator bool() const noexcept
+    {
+        return v_.index() == 0;
+    }
+
+    // checked value access
+
+    BOOST_CXX14_CONSTEXPR void value( boost::source_location const& loc = BOOST_CURRENT_LOCATION ) const
+    {
+        if( has_value() )
+        {
+        }
+        else
+        {
+            throw_exception_from_error( variant2::unsafe_get<1>( v_ ), loc );
+        }
+    }
+
+    // unchecked value access
+
+    BOOST_CXX14_CONSTEXPR void* operator->() noexcept
+    {
+        return variant2::get_if<0>( &v_ );
+    }
+
+    BOOST_CXX14_CONSTEXPR void const* operator->() const noexcept
+    {
+        return variant2::get_if<0>( &v_ );
+    }
+
+    BOOST_CXX14_CONSTEXPR void operator*() const noexcept
+    {
+        BOOST_ASSERT( has_value() );
+    }
+
+    // error access
+
+    constexpr E error() const
+        noexcept( std::is_nothrow_default_constructible<E>::value && std::is_nothrow_copy_constructible<E>::value )
+    {
+        return has_error()? variant2::unsafe_get<1>( v_ ): E();
+    }
+
+    // swap
+
+    BOOST_CXX14_CONSTEXPR void swap( result& r )
+        noexcept( noexcept( v_.swap( r.v_ ) ) )
+    {
+        v_.swap( r.v_ );
+    }
+
+    friend BOOST_CXX14_CONSTEXPR void swap( result & r1, result & r2 )
+        noexcept( noexcept( r1.swap( r2 ) ) )
+    {
+        r1.swap( r2 );
+    }
+
+    // equality
+
+    friend constexpr bool operator==( result const & r1, result const & r2 )
+        noexcept( noexcept( r1.v_ == r2.v_ ) )
+    {
+        return r1.v_ == r2.v_;
+    }
+
+    friend constexpr bool operator!=( result const & r1, result const & r2 )
+        noexcept( noexcept( !( r1 == r2 ) ) )
+    {
+        return !( r1 == r2 );
+    }
+};
+
+template<class Ch, class Tr, class E> std::basic_ostream<Ch, Tr>& operator<<( std::basic_ostream<Ch, Tr>& os, result<void, E> const & r )
+{
+    if( r.has_value() )
+    {
+        os << "value:void";
+    }
+    else
+    {
+        os << "error:" << r.error();
+    }
+
+    return os;
+}
+
+} // namespace system
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_RESULT_HPP_INCLUDED

include/boost/system/system_category.hpp

@@ -0,0 +1,14 @@
+#ifndef BOOST_SYSTEM_SYSTEM_CATEGORY_HPP_INCLUDED
+#define BOOST_SYSTEM_SYSTEM_CATEGORY_HPP_INCLUDED
+
+// Copyright 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0
+// http://www.boost.org/LICENSE_1_0.txt
+//
+// See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/system_category.hpp>
+#include <boost/system/detail/system_category_impl.hpp>
+#include <boost/system/detail/error_category_impl.hpp>
+
+#endif // #ifndef BOOST_SYSTEM_SYSTEM_CATEGORY_HPP_INCLUDED

include/boost/system/system_error.hpp

@@ -1,81 +1,55 @@
-//  Boost system_error.hpp  --------------------------------------------------//
+#ifndef BOOST_SYSTEM_SYSTEM_ERROR_HPP
+#define BOOST_SYSTEM_SYSTEM_ERROR_HPP
 
-//  Copyright Beman Dawes 2006
-
-//  Distributed under the Boost Software License, Version 1.0. (See accompanying
-//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-
-#ifndef BOOST_SYSTEM_ERROR_HPP
-#define BOOST_SYSTEM_ERROR_HPP
+// Copyright Beman Dawes 2006
+// Copyright Peter Dimov 2021
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
 
+#include <boost/system/errc.hpp>
+#include <boost/system/detail/error_code.hpp>
 #include <string>
 #include <stdexcept>
 #include <cassert>
-#include <boost/system/error_code.hpp>
 
 namespace boost
 {
-  namespace system
-  {
-    //  class system_error  --------------------------------------------------//
+namespace system
+{
 
-    class system_error : public std::runtime_error
+class BOOST_SYMBOL_VISIBLE system_error: public std::runtime_error
+{
+private:
+
+    error_code code_;
+
+public:
+
+    explicit system_error( error_code const & ec ):
+        std::runtime_error( ec.what() ), code_( ec ) {}
+
+    system_error( error_code const & ec, std::string const & prefix ):
+        std::runtime_error( prefix + ": " + ec.what() ), code_( ec ) {}
+
+    system_error( error_code const & ec, char const * prefix ):
+        std::runtime_error( std::string( prefix ) + ": " + ec.what() ), code_( ec ) {}
+
+    system_error( int ev, error_category const & ecat ):
+        std::runtime_error( error_code( ev, ecat ).what() ), code_( ev, ecat ) {}
+
+    system_error( int ev, error_category const & ecat, std::string const & prefix ):
+        std::runtime_error( prefix + ": " + error_code( ev, ecat ).what() ), code_( ev, ecat ) {}
+
+    system_error( int ev, error_category const & ecat, char const * prefix ):
+        std::runtime_error( std::string( prefix ) + ": " + error_code( ev, ecat ).what() ), code_( ev, ecat ) {}
+
+    error_code code() const BOOST_NOEXCEPT
     {
-    public:
-      system_error( error_code ec )
-          : std::runtime_error(""), m_error_code(ec) {}
-
-      system_error( error_code ec, const std::string & what_arg )
-          : std::runtime_error(what_arg), m_error_code(ec) {}
-
-      system_error( error_code ec, const char* what_arg )
-          : std::runtime_error(what_arg), m_error_code(ec) {}
-
-      system_error( int ev, const error_category & ecat )
-          : std::runtime_error(""), m_error_code(ev,ecat) {}
-
-      system_error( int ev, const error_category & ecat,
-        const std::string & what_arg )
-          : std::runtime_error(what_arg), m_error_code(ev,ecat) {}
-
-      system_error( int ev, const error_category & ecat,
-        const char * what_arg )
-          : std::runtime_error(what_arg), m_error_code(ev,ecat) {}
-
-      virtual ~system_error() throw() {}
-
-      const error_code &  code() const throw() { return m_error_code; }
-      const char *        what() const throw();
-
-    private:
-      error_code           m_error_code;
-      mutable std::string  m_what;
-    };
-
-    //  implementation  ------------------------------------------------------//
-
-    inline const char * system_error::what() const throw()
-    // see http://www.boost.org/more/error_handling.html for lazy build rationale
-    {
-      if ( m_what.empty() )
-      {
-        try
-        {
-          m_what = this->std::runtime_error::what();
-          if ( m_error_code )
-          {
-            if ( !m_what.empty() ) m_what += ": ";
-            m_what += m_error_code.message();
-          }
-        }
-        catch (...) { return std::runtime_error::what(); }
-      }
-      return m_what.c_str();
+        return code_;
     }
+};
 
-  } // namespace system
+} // namespace system
 } // namespace boost
 
-#endif // BOOST_SYSTEM_ERROR_HPP
-
-
+#endif // BOOST_SYSTEM_SYSTEM_ERROR_HPP

include/boost/system/windows_error.hpp

@@ -7,8 +7,8 @@
 
 //  See library home page at http://www.boost.org/libs/system
 
-#ifndef BOOST_WINDOWS_ERROR_HPP
-#define BOOST_WINDOWS_ERROR_HPP
+#ifndef BOOST_SYSTEM_WINDOWS_ERROR_HPP
+#define BOOST_SYSTEM_WINDOWS_ERROR_HPP
 
 //  This header is effectively empty for compiles on operating systems where
 //  it is not applicable.
@@ -18,7 +18,7 @@
 #ifdef BOOST_WINDOWS_API
 
 #include <boost/system/error_code.hpp>
-#include <winerror.h>
+#include <boost/winapi/error_codes.hpp>
 
 namespace boost
 {
@@ -29,7 +29,7 @@ namespace boost
 
     //  To construct an error_code after a API error:
     //
-    //      error_code( ::GetLastError(), system_category )
+    //      error_code( ::GetLastError(), system_category() )
 
     namespace windows_error
     {
@@ -37,59 +37,60 @@ namespace boost
       {
         success = 0,
         // These names and values are based on Windows winerror.h
-        invalid_function = ERROR_INVALID_FUNCTION,
-        file_not_found = ERROR_FILE_NOT_FOUND,
-        path_not_found = ERROR_PATH_NOT_FOUND,
-        too_many_open_files = ERROR_TOO_MANY_OPEN_FILES,
-        access_denied = ERROR_ACCESS_DENIED,
-        invalid_handle = ERROR_INVALID_HANDLE,
-        arena_trashed = ERROR_ARENA_TRASHED,
-        not_enough_memory = ERROR_NOT_ENOUGH_MEMORY,
-        invalid_block = ERROR_INVALID_BLOCK,
-        bad_environment = ERROR_BAD_ENVIRONMENT,
-        bad_format = ERROR_BAD_FORMAT,
-        invalid_access = ERROR_INVALID_ACCESS,
-        outofmemory = ERROR_OUTOFMEMORY,
-        invalid_drive = ERROR_INVALID_DRIVE,
-        current_directory = ERROR_CURRENT_DIRECTORY,
-        not_same_device = ERROR_NOT_SAME_DEVICE,
-        no_more_files = ERROR_NO_MORE_FILES,
-        write_protect = ERROR_WRITE_PROTECT,
-        bad_unit = ERROR_BAD_UNIT,
-        not_ready = ERROR_NOT_READY,
-        bad_command = ERROR_BAD_COMMAND,
-        crc = ERROR_CRC,
-        bad_length = ERROR_BAD_LENGTH,
-        seek = ERROR_SEEK,
-        not_dos_disk = ERROR_NOT_DOS_DISK,
-        sector_not_found = ERROR_SECTOR_NOT_FOUND,
-        out_of_paper = ERROR_OUT_OF_PAPER,
-        write_fault = ERROR_WRITE_FAULT,
-        read_fault = ERROR_READ_FAULT,
-        gen_failure = ERROR_GEN_FAILURE,
-        sharing_violation = ERROR_SHARING_VIOLATION,
-        lock_violation = ERROR_LOCK_VIOLATION,
-        wrong_disk = ERROR_WRONG_DISK,
-        sharing_buffer_exceeded = ERROR_SHARING_BUFFER_EXCEEDED,
-        handle_eof = ERROR_HANDLE_EOF,
-        handle_disk_full= ERROR_HANDLE_DISK_FULL,
-        rem_not_list = ERROR_REM_NOT_LIST,
-        dup_name = ERROR_DUP_NAME,
-        bad_net_path = ERROR_BAD_NETPATH,
-        network_busy = ERROR_NETWORK_BUSY,
+        invalid_function = boost::winapi::ERROR_INVALID_FUNCTION_,
+        file_not_found = boost::winapi::ERROR_FILE_NOT_FOUND_,
+        path_not_found = boost::winapi::ERROR_PATH_NOT_FOUND_,
+        too_many_open_files = boost::winapi::ERROR_TOO_MANY_OPEN_FILES_,
+        access_denied = boost::winapi::ERROR_ACCESS_DENIED_,
+        invalid_handle = boost::winapi::ERROR_INVALID_HANDLE_,
+        arena_trashed = boost::winapi::ERROR_ARENA_TRASHED_,
+        not_enough_memory = boost::winapi::ERROR_NOT_ENOUGH_MEMORY_,
+        invalid_block = boost::winapi::ERROR_INVALID_BLOCK_,
+        bad_environment = boost::winapi::ERROR_BAD_ENVIRONMENT_,
+        bad_format = boost::winapi::ERROR_BAD_FORMAT_,
+        invalid_access = boost::winapi::ERROR_INVALID_ACCESS_,
+        outofmemory = boost::winapi::ERROR_OUTOFMEMORY_,
+        invalid_drive = boost::winapi::ERROR_INVALID_DRIVE_,
+        current_directory = boost::winapi::ERROR_CURRENT_DIRECTORY_,
+        not_same_device = boost::winapi::ERROR_NOT_SAME_DEVICE_,
+        no_more_files = boost::winapi::ERROR_NO_MORE_FILES_,
+        write_protect = boost::winapi::ERROR_WRITE_PROTECT_,
+        bad_unit = boost::winapi::ERROR_BAD_UNIT_,
+        not_ready = boost::winapi::ERROR_NOT_READY_,
+        bad_command = boost::winapi::ERROR_BAD_COMMAND_,
+        crc = boost::winapi::ERROR_CRC_,
+        bad_length = boost::winapi::ERROR_BAD_LENGTH_,
+        seek = boost::winapi::ERROR_SEEK_,
+        not_dos_disk = boost::winapi::ERROR_NOT_DOS_DISK_,
+        sector_not_found = boost::winapi::ERROR_SECTOR_NOT_FOUND_,
+        out_of_paper = boost::winapi::ERROR_OUT_OF_PAPER_,
+        write_fault = boost::winapi::ERROR_WRITE_FAULT_,
+        read_fault = boost::winapi::ERROR_READ_FAULT_,
+        gen_failure = boost::winapi::ERROR_GEN_FAILURE_,
+        sharing_violation = boost::winapi::ERROR_SHARING_VIOLATION_,
+        lock_violation = boost::winapi::ERROR_LOCK_VIOLATION_,
+        wrong_disk = boost::winapi::ERROR_WRONG_DISK_,
+        sharing_buffer_exceeded = boost::winapi::ERROR_SHARING_BUFFER_EXCEEDED_,
+        handle_eof = boost::winapi::ERROR_HANDLE_EOF_,
+        handle_disk_full = boost::winapi::ERROR_HANDLE_DISK_FULL_,
+        not_supported = boost::winapi::ERROR_NOT_SUPPORTED_,
+        rem_not_list = boost::winapi::ERROR_REM_NOT_LIST_,
+        dup_name = boost::winapi::ERROR_DUP_NAME_,
+        bad_net_path = boost::winapi::ERROR_BAD_NETPATH_,
+        network_busy = boost::winapi::ERROR_NETWORK_BUSY_,
         // ...
-        file_exists = ERROR_FILE_EXISTS,
-        cannot_make = ERROR_CANNOT_MAKE,
+        file_exists = boost::winapi::ERROR_FILE_EXISTS_,
+        cannot_make = boost::winapi::ERROR_CANNOT_MAKE_,
         // ...
-        broken_pipe = ERROR_BROKEN_PIPE,
-        open_failed = ERROR_OPEN_FAILED,
-        buffer_overflow = ERROR_BUFFER_OVERFLOW,
-        disk_full= ERROR_DISK_FULL,
+        broken_pipe = boost::winapi::ERROR_BROKEN_PIPE_,
+        open_failed = boost::winapi::ERROR_OPEN_FAILED_,
+        buffer_overflow = boost::winapi::ERROR_BUFFER_OVERFLOW_,
+        disk_full = boost::winapi::ERROR_DISK_FULL_,
         // ...
-        lock_failed = ERROR_LOCK_FAILED,
-        busy = ERROR_BUSY,
-        cancel_violation = ERROR_CANCEL_VIOLATION,
-        already_exists = ERROR_ALREADY_EXISTS
+        lock_failed = boost::winapi::ERROR_LOCK_FAILED_,
+        busy = boost::winapi::ERROR_BUSY_,
+        cancel_violation = boost::winapi::ERROR_CANCEL_VIOLATION_,
+        already_exists = boost::winapi::ERROR_ALREADY_EXISTS_
         // ...
 
         // TODO: add more Windows errors
@@ -97,7 +98,7 @@ namespace boost
 
     }  // namespace windows
 
-# ifndef BOOST_SYSTEM_NO_DEPRECATED
+# ifdef BOOST_SYSTEM_ENABLE_DEPRECATED
     namespace windows = windows_error;
 # endif
 
@@ -107,7 +108,7 @@ namespace boost
     namespace windows_error
     {
       inline error_code make_error_code( windows_error_code e )
-        { return error_code( e, get_system_category() ); }
+        { return error_code( e, system_category() ); }
     }
 
   }  // namespace system
@@ -115,4 +116,4 @@ namespace boost
 
 #endif  // BOOST_WINDOWS_API
 
-#endif  // BOOST_WINDOWS_ERROR_HPP
+#endif  // BOOST_SYSTEM_WINDOWS_ERROR_HPP

index.html

@@ -1,14 +1,15 @@
 <html>
 <head>
-<meta http-equiv="refresh" content="0; URL=doc/index.html">
+<meta http-equiv="refresh" content="0; URL=doc/html/system.html">
 </head>
 <body>
 Automatic redirection failed, please go to
-<a href="doc/index.html">doc/index.html</a>.
-<hr>
-<p><EFBFBD> Copyright Beman Dawes, 2003</p>
-<p> Distribution under the Boost Software License, Version 1.0.
-(See accompanying file <a href="../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">
-www.boost.org/LICENSE_1_0.txt</a>)</p>
+<a href="doc/html/system.html">doc/html/system.html</a>.
 </body>
-</html>
+</html>
+<!--
+	© Copyright Beman Dawes, 2001
+	Distributed under the Boost Software License, Version 1.0.
+	See accompanying file LICENSE_1_0.txt or copy at
+	https://www.boost.org/LICENSE_1_0.txt
+-->

meta/libraries.json

@@ -0,0 +1,17 @@
+{
+    "key": "system",
+    "name": "System",
+    "authors": [
+        "Beman Dawes"
+    ],
+    "maintainers": [
+        "Peter Dimov <pdimov -at- gmail.com>"
+    ],
+    "description": "Extensible error reporting.",
+    "category": [
+        "System",
+        "Error-handling",
+        "Programming"
+    ],
+    "cxxstd": "03"
+}

src/error_code.cpp

@@ -1,6 +1,7 @@
-//  error_code support implementation file  ----------------------------------//
+//  error_code stub implementation, for compatibility only
 
 //  Copyright Beman Dawes 2002, 2006
+//  Copyright Peter Dimov 2018
 
 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
@@ -9,427 +10,22 @@
 
 //----------------------------------------------------------------------------//
 
-#include <boost/config/warning_disable.hpp>
-
 // define BOOST_SYSTEM_SOURCE so that <boost/system/config.hpp> knows
 // the library is being built (possibly exporting rather than importing code)
-#define BOOST_SYSTEM_SOURCE 
+#define BOOST_SYSTEM_SOURCE
 
 #include <boost/system/config.hpp>
-#include <boost/system/error_code.hpp>
-#include <boost/cerrno.hpp>
-#include <vector>
-#include <cstdlib>
-#include <cassert>
-
-using namespace boost::system;
-using namespace boost::system::errc;
-
-#include <cstring> // for strerror/strerror_r
-
-# if defined( BOOST_WINDOWS_API )
-#   include <windows.h>
-#   ifndef ERROR_INCORRECT_SIZE
-#    define ERROR_INCORRECT_SIZE ERROR_BAD_ARGUMENTS
-#   endif
-# endif
-
-//----------------------------------------------------------------------------//
-
-namespace
-{
-  //  standard error categories  ---------------------------------------------//
-
-  class generic_error_category : public error_category
-  {
-  public:
-    generic_error_category(){}
-    const char *   name() const;
-    std::string    message( int ev ) const;
-  };
-
-  class system_error_category : public error_category
-  {
-  public:
-    system_error_category(){}
-    const char *        name() const;
-    std::string         message( int ev ) const;
-    error_condition     default_error_condition( int ev ) const;
-  };
-
-  //  generic_error_category implementation  ---------------------------------//
-
-  const char * generic_error_category::name() const
-  {
-    return "generic";
-  }
-
-  std::string generic_error_category::message( int ev ) const
-  {
-    static std::string unknown_err( "Unknown error" );
-  // strerror_r is preferred because it is always thread safe,
-  // however, we fallback to strerror in certain cases because:
-  //   -- Windows doesn't provide strerror_r.
-  //   -- HP and Sundo provide strerror_r on newer systems, but there is
-  //      no way to tell if is available at runtime and in any case their
-  //      versions of strerror are thread safe anyhow.
-  //   -- Linux only sometimes provides strerror_r.
-  //   -- Tru64 provides strerror_r only when compiled -pthread.
-  //   -- VMS doesn't provide strerror_r, but on this platform, strerror is
-  //      thread safe.
-  # if defined(BOOST_WINDOWS_API) || defined(__hpux) || defined(__sun)\
-     || (defined(__linux) && (!defined(__USE_XOPEN2K) || defined(BOOST_SYSTEM_USE_STRERROR)))\
-     || (defined(__osf__) && !defined(_REENTRANT))\
-     || (defined(__vms))\
-     || (defined(__QNXNTO__))
-      const char * c_str = std::strerror( ev );
-      return  c_str
-        ? std::string( c_str )
-        : unknown_err;
-  # else  // use strerror_r
-      char buf[64];
-      char * bp = buf;
-      std::size_t sz = sizeof(buf);
-  #  if defined(__CYGWIN__) || defined(__USE_GNU)
-      // Oddball version of strerror_r
-      const char * c_str = strerror_r( ev, bp, sz );
-      return  c_str
-        ? std::string( c_str )
-        : unknown_err;
-  #  else
-      // POSIX version of strerror_r
-      int result;
-      for (;;)
-      {
-        // strerror_r returns 0 on success, otherwise ERANGE if buffer too small,
-        // invalid_argument if ev not a valid error number
-  #  if defined (__sgi)
-        const char * c_str = strerror( ev );
-        result = 0;
-      return  c_str
-        ? std::string( c_str )
-        : unknown_err;
-  #  else
-        result = strerror_r( ev, bp, sz );
-  #  endif
-        if (result == 0 )
-          break;
-        else
-        {
-  #  if defined(__linux)
-          // Linux strerror_r returns -1 on error, with error number in errno
-          result = errno;
-  #  endif
-          if ( result !=  ERANGE ) break;
-          if ( sz > sizeof(buf) ) std::free( bp );
-          sz *= 2;
-          if ( (bp = static_cast<char*>(std::malloc( sz ))) == 0 )
-            return std::string( "ENOMEM" );
-        }
-      }
-      std::string msg;
-      try
-      {
-        msg = ( ( result == invalid_argument ) ? "Unknown error" : bp );
-      }
-
-#   ifndef BOOST_NO_EXCEPTIONS
-      // See ticket #2098
-      catch(...)
-      {
-        // just eat the exception
-      }
-#   endif
-
-      if ( sz > sizeof(buf) ) std::free( bp );
-      sz = 0;
-      return msg;
-  #  endif   // else POSIX version of strerror_r
-  # endif  // else use strerror_r
-  }
-  //  system_error_category implementation  --------------------------------// 
-
-  const char * system_error_category::name() const
-  {
-    return "system";
-  }
-
-  error_condition system_error_category::default_error_condition( int ev ) const
-  {
-    switch ( ev )
-    {
-    case 0: return make_error_condition( success );
-  # if defined(BOOST_POSIX_API)
-    // POSIX-like O/S -> posix_errno decode table  ---------------------------//
-    case E2BIG: return make_error_condition( argument_list_too_long );
-    case EACCES: return make_error_condition( permission_denied );
-    case EADDRINUSE: return make_error_condition( address_in_use );
-    case EADDRNOTAVAIL: return make_error_condition( address_not_available );
-    case EAFNOSUPPORT: return make_error_condition( address_family_not_supported );
-    case EAGAIN: return make_error_condition( resource_unavailable_try_again );
-#   if EALREADY != EBUSY  //  EALREADY and EBUSY are the same on QNX Neutrino
-    case EALREADY: return make_error_condition( connection_already_in_progress );
-#   endif
-    case EBADF: return make_error_condition( bad_file_descriptor );
-    case EBADMSG: return make_error_condition( bad_message );
-    case EBUSY: return make_error_condition( device_or_resource_busy );
-    case ECANCELED: return make_error_condition( operation_canceled );
-    case ECHILD: return make_error_condition( no_child_process );
-    case ECONNABORTED: return make_error_condition( connection_aborted );
-    case ECONNREFUSED: return make_error_condition( connection_refused );
-    case ECONNRESET: return make_error_condition( connection_reset );
-    case EDEADLK: return make_error_condition( resource_deadlock_would_occur );
-    case EDESTADDRREQ: return make_error_condition( destination_address_required );
-    case EDOM: return make_error_condition( argument_out_of_domain );
-    case EEXIST: return make_error_condition( file_exists );
-    case EFAULT: return make_error_condition( bad_address );
-    case EFBIG: return make_error_condition( file_too_large );
-    case EHOSTUNREACH: return make_error_condition( host_unreachable );
-    case EIDRM: return make_error_condition( identifier_removed );
-    case EILSEQ: return make_error_condition( illegal_byte_sequence );
-    case EINPROGRESS: return make_error_condition( operation_in_progress );
-    case EINTR: return make_error_condition( interrupted );
-    case EINVAL: return make_error_condition( invalid_argument );
-    case EIO: return make_error_condition( io_error );
-    case EISCONN: return make_error_condition( already_connected );
-    case EISDIR: return make_error_condition( is_a_directory );
-    case ELOOP: return make_error_condition( too_many_synbolic_link_levels );
-    case EMFILE: return make_error_condition( too_many_files_open );
-    case EMLINK: return make_error_condition( too_many_links );
-    case EMSGSIZE: return make_error_condition( message_size );
-    case ENAMETOOLONG: return make_error_condition( filename_too_long );
-    case ENETDOWN: return make_error_condition( network_down );
-    case ENETRESET: return make_error_condition( network_reset );
-    case ENETUNREACH: return make_error_condition( network_unreachable );
-    case ENFILE: return make_error_condition( too_many_files_open_in_system );
-    case ENOBUFS: return make_error_condition( no_buffer_space );
-    case ENODATA: return make_error_condition( no_message_available );
-    case ENODEV: return make_error_condition( no_such_device );
-    case ENOENT: return make_error_condition( no_such_file_or_directory );
-    case ENOEXEC: return make_error_condition( executable_format_error );
-    case ENOLCK: return make_error_condition( no_lock_available );
-    case ENOLINK: return make_error_condition( no_link );
-    case ENOMEM: return make_error_condition( not_enough_memory );
-    case ENOMSG: return make_error_condition( no_message );
-    case ENOPROTOOPT: return make_error_condition( no_protocol_option );
-    case ENOSPC: return make_error_condition( no_space_on_device );
-    case ENOSR: return make_error_condition( no_stream_resources );
-    case ENOSTR: return make_error_condition( not_a_stream );
-    case ENOSYS: return make_error_condition( function_not_supported );
-    case ENOTCONN: return make_error_condition( not_connected );
-    case ENOTDIR: return make_error_condition( not_a_directory );
-  # if ENOTEMPTY != EEXIST // AIX treats ENOTEMPTY and EEXIST as the same value
-    case ENOTEMPTY: return make_error_condition( directory_not_empty );
-  # endif // ENOTEMPTY != EEXIST
-    case ENOTRECOVERABLE: return make_error_condition( state_not_recoverable );
-    case ENOTSOCK: return make_error_condition( not_a_socket );
-    case ENOTSUP: return make_error_condition( not_supported );
-    case ENOTTY: return make_error_condition( inappropriate_io_control_operation );
-    case ENXIO: return make_error_condition( no_such_device_or_address );
-  # if EOPNOTSUPP != ENOTSUP
-    case EOPNOTSUPP: return make_error_condition( operation_not_supported );
-  # endif // EOPNOTSUPP != ENOTSUP
-    case EOVERFLOW: return make_error_condition( value_too_large );
-    case EOWNERDEAD: return make_error_condition( owner_dead );
-    case EPERM: return make_error_condition( operation_not_permitted );
-    case EPIPE: return make_error_condition( broken_pipe );
-    case EPROTO: return make_error_condition( protocol_error );
-    case EPROTONOSUPPORT: return make_error_condition( protocol_not_supported );
-    case EPROTOTYPE: return make_error_condition( wrong_protocol_type );
-    case ERANGE: return make_error_condition( result_out_of_range );
-    case EROFS: return make_error_condition( read_only_file_system );
-    case ESPIPE: return make_error_condition( invalid_seek );
-    case ESRCH: return make_error_condition( no_such_process );
-    case ETIME: return make_error_condition( stream_timeout );
-    case ETIMEDOUT: return make_error_condition( timed_out );
-    case ETXTBSY: return make_error_condition( text_file_busy );
-  # if EAGAIN != EWOULDBLOCK
-    case EWOULDBLOCK: return make_error_condition( operation_would_block );
-  # endif // EAGAIN != EWOULDBLOCK
-    case EXDEV: return make_error_condition( cross_device_link );
-  #else
-    // Windows system -> posix_errno decode table  ---------------------------//
-    // see WinError.h comments for descriptions of errors
-    case ERROR_ACCESS_DENIED: return make_error_condition( permission_denied );
-    case ERROR_ALREADY_EXISTS: return make_error_condition( file_exists );
-    case ERROR_BAD_UNIT: return make_error_condition( no_such_device );
-    case ERROR_BUFFER_OVERFLOW: return make_error_condition( filename_too_long );
-    case ERROR_BUSY: return make_error_condition( device_or_resource_busy );
-    case ERROR_BUSY_DRIVE: return make_error_condition( device_or_resource_busy );
-    case ERROR_CANNOT_MAKE: return make_error_condition( permission_denied );
-    case ERROR_CANTOPEN: return make_error_condition( io_error );
-    case ERROR_CANTREAD: return make_error_condition( io_error );
-    case ERROR_CANTWRITE: return make_error_condition( io_error );
-    case ERROR_CURRENT_DIRECTORY: return make_error_condition( permission_denied );
-    case ERROR_DEV_NOT_EXIST: return make_error_condition( no_such_device );
-    case ERROR_DEVICE_IN_USE: return make_error_condition( device_or_resource_busy );
-    case ERROR_DIR_NOT_EMPTY: return make_error_condition( directory_not_empty );
-    case ERROR_DIRECTORY: return make_error_condition( invalid_argument ); // WinError.h: "The directory name is invalid"
-    case ERROR_DISK_FULL: return make_error_condition( no_space_on_device );
-    case ERROR_FILE_EXISTS: return make_error_condition( file_exists );
-    case ERROR_FILE_NOT_FOUND: return make_error_condition( no_such_file_or_directory );
-    case ERROR_HANDLE_DISK_FULL: return make_error_condition( no_space_on_device );
-    case ERROR_INVALID_ACCESS: return make_error_condition( permission_denied );
-    case ERROR_INVALID_DRIVE: return make_error_condition( no_such_device );
-    case ERROR_INVALID_FUNCTION: return make_error_condition( function_not_supported );
-    case ERROR_INVALID_HANDLE: return make_error_condition( invalid_argument );
-    case ERROR_INVALID_NAME: return make_error_condition( invalid_argument );
-    case ERROR_LOCK_VIOLATION: return make_error_condition( no_lock_available );
-    case ERROR_LOCKED: return make_error_condition( no_lock_available );
-    case ERROR_NEGATIVE_SEEK: return make_error_condition( invalid_argument );
-    case ERROR_NOACCESS: return make_error_condition( permission_denied );
-    case ERROR_NOT_ENOUGH_MEMORY: return make_error_condition( not_enough_memory );
-    case ERROR_NOT_READY: return make_error_condition( resource_unavailable_try_again );
-    case ERROR_NOT_SAME_DEVICE: return make_error_condition( cross_device_link );
-    case ERROR_OPEN_FAILED: return make_error_condition( io_error );
-    case ERROR_OPEN_FILES: return make_error_condition( device_or_resource_busy );
-    case ERROR_OPERATION_ABORTED: return make_error_condition( operation_canceled );
-    case ERROR_OUTOFMEMORY: return make_error_condition( not_enough_memory );
-    case ERROR_PATH_NOT_FOUND: return make_error_condition( no_such_file_or_directory );
-    case ERROR_READ_FAULT: return make_error_condition( io_error );
-    case ERROR_RETRY: return make_error_condition( resource_unavailable_try_again );
-    case ERROR_SEEK: return make_error_condition( io_error );
-    case ERROR_SHARING_VIOLATION: return make_error_condition( permission_denied );
-    case ERROR_TOO_MANY_OPEN_FILES: return make_error_condition( too_many_files_open );
-    case ERROR_WRITE_FAULT: return make_error_condition( io_error );
-    case ERROR_WRITE_PROTECT: return make_error_condition( permission_denied );
-    case WSAEACCES: return make_error_condition( permission_denied );
-    case WSAEADDRINUSE: return make_error_condition( address_in_use );
-    case WSAEADDRNOTAVAIL: return make_error_condition( address_not_available );
-    case WSAEAFNOSUPPORT: return make_error_condition( address_family_not_supported );
-    case WSAEALREADY: return make_error_condition( connection_already_in_progress );
-    case WSAEBADF: return make_error_condition( bad_file_descriptor );
-    case WSAECONNABORTED: return make_error_condition( connection_aborted );
-    case WSAECONNREFUSED: return make_error_condition( connection_refused );
-    case WSAECONNRESET: return make_error_condition( connection_reset );
-    case WSAEDESTADDRREQ: return make_error_condition( destination_address_required );
-    case WSAEFAULT: return make_error_condition( bad_address );
-    case WSAEHOSTUNREACH: return make_error_condition( host_unreachable );
-    case WSAEINPROGRESS: return make_error_condition( operation_in_progress );
-    case WSAEINTR: return make_error_condition( interrupted );
-    case WSAEINVAL: return make_error_condition( invalid_argument );
-    case WSAEISCONN: return make_error_condition( already_connected );
-    case WSAEMFILE: return make_error_condition( too_many_files_open );
-    case WSAEMSGSIZE: return make_error_condition( message_size );
-    case WSAENAMETOOLONG: return make_error_condition( filename_too_long );
-    case WSAENETDOWN: return make_error_condition( network_down );
-    case WSAENETRESET: return make_error_condition( network_reset );
-    case WSAENETUNREACH: return make_error_condition( network_unreachable );
-    case WSAENOBUFS: return make_error_condition( no_buffer_space );
-    case WSAENOPROTOOPT: return make_error_condition( no_protocol_option );
-    case WSAENOTCONN: return make_error_condition( not_connected );
-    case WSAENOTSOCK: return make_error_condition( not_a_socket );
-    case WSAEOPNOTSUPP: return make_error_condition( operation_not_supported );
-    case WSAEPROTONOSUPPORT: return make_error_condition( protocol_not_supported );
-    case WSAEPROTOTYPE: return make_error_condition( wrong_protocol_type );
-    case WSAETIMEDOUT: return make_error_condition( timed_out );
-    case WSAEWOULDBLOCK: return make_error_condition( operation_would_block );
-  #endif
-    default: return error_condition( ev, system_category );
-    }
-  }
-
-# if !defined( BOOST_WINDOWS_API )
-
-  std::string system_error_category::message( int ev ) const
-  {
-    return generic_category.message( ev );
-  }
-# else
-// TODO:
-  
-//Some quick notes on the implementation (sorry for the noise if
-//someone has already mentioned them):
-//
-//- The ::LocalFree() usage isn't exception safe.
-//
-//See:
-//
-//<http://boost.cvs.sourceforge.net/boost/boost/boost/asio/system_exception.hpp?revision=1.1&view=markup>
-//
-//in the implementation of what() for an example.
-//
-//Cheers,
-//Chris
-  std::string system_error_category::message( int ev ) const
-  {
-# ifndef BOOST_NO_ANSI_APIS  
-    LPVOID lpMsgBuf;
-    DWORD retval = ::FormatMessageA( 
-        FORMAT_MESSAGE_ALLOCATE_BUFFER | 
-        FORMAT_MESSAGE_FROM_SYSTEM | 
-        FORMAT_MESSAGE_IGNORE_INSERTS,
-        NULL,
-        ev,
-        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
-        (LPSTR) &lpMsgBuf,
-        0,
-        NULL 
-    );
-    if (retval == 0)
-        return std::string("Unknown error");
-        
-    std::string str( static_cast<LPCSTR>(lpMsgBuf) );
-    ::LocalFree( lpMsgBuf ); // free the buffer
-# else  // WinCE workaround
-    LPVOID lpMsgBuf;
-    DWORD retval = ::FormatMessageW( 
-        FORMAT_MESSAGE_ALLOCATE_BUFFER | 
-        FORMAT_MESSAGE_FROM_SYSTEM | 
-        FORMAT_MESSAGE_IGNORE_INSERTS,
-        NULL,
-        ev,
-        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
-        (LPWSTR) &lpMsgBuf,
-        0,
-        NULL 
-    );
-    if (retval == 0)
-        return std::string("Unknown error");
-    
-    int num_chars = (wcslen( static_cast<LPCWSTR>(lpMsgBuf) ) + 1) * 2;
-    LPSTR narrow_buffer = (LPSTR)_alloca( num_chars );
-    if (::WideCharToMultiByte(CP_ACP, 0, static_cast<LPCWSTR>(lpMsgBuf), -1, narrow_buffer, num_chars, NULL, NULL) == 0)
-        return std::string("Unknown error");
-
-    std::string str( narrow_buffer );
-    ::LocalFree( lpMsgBuf ); // free the buffer
-# endif
-    while ( str.size()
-      && (str[str.size()-1] == '\n' || str[str.size()-1] == '\r') )
-        str.erase( str.size()-1 );
-    if ( str.size() && str[str.size()-1] == '.' ) 
-      { str.erase( str.size()-1 ); }
-    return str;
-  }
-# endif
-
-} // unnamed namespace
 
 namespace boost
 {
-  namespace system
-  {
 
-# ifndef BOOST_SYSTEM_NO_DEPRECATED
-    BOOST_SYSTEM_DECL error_code throws; // "throw on error" special error_code;
-                                         //  note that it doesn't matter if this
-                                         //  isn't initialized before use since
-                                         //  the only use is to take its
-                                         //  address for comparison purposes
-# endif
+namespace system
+{
 
-    BOOST_SYSTEM_DECL const error_category & get_system_category()
-    {
-      static const system_error_category  system_category_const;
-      return system_category_const;
-    }
+BOOST_SYSTEM_DECL void dummy_exported_function()
+{
+}
 
-    BOOST_SYSTEM_DECL const error_category & get_generic_category()
-    {
-      static const generic_error_category generic_category_const;
-      return generic_category_const;
-    }
+} // namespace system
 
-  } // namespace system
 } // namespace boost

test/CMakeLists.txt

@@ -0,0 +1,145 @@
+# Copyright 2018-2020 Peter Dimov
+# Distributed under the Boost Software License, Version 1.0.
+# See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt
+
+include(BoostTest OPTIONAL RESULT_VARIABLE HAVE_BOOST_TEST)
+
+if(NOT HAVE_BOOST_TEST)
+  return()
+endif()
+
+macro(system_run s1)
+
+  string(MAKE_C_IDENTIFIER ${s1} n1)
+
+  boost_test(SOURCES ${s1} ${ARGN})
+  boost_test(SOURCES ${s1} ${ARGN} COMPILE_DEFINITIONS BOOST_NO_ANSI_APIS NAME ${n1}_no_ansi)
+  boost_test(SOURCES ${s1} ${ARGN} COMPILE_DEFINITIONS BOOST_SYSTEM_USE_UTF8 NAME ${n1}_utf8)
+
+endmacro()
+
+macro(lib name macro)
+
+  add_library(${name} EXCLUDE_FROM_ALL ${ARGN})
+  target_compile_definitions(${name} PRIVATE $<$<BOOL:BUILD_SHARED_LIBS>:${macro}=1>)
+  target_link_libraries(${name} PRIVATE Boost::system Boost::config)
+
+endmacro()
+
+set(BOOST_TEST_LINK_LIBRARIES Boost::system Boost::core Boost::static_assert)
+
+boost_test(SOURCES quick.cpp)
+
+system_run(error_code_test.cpp)
+system_run(error_code_user_test.cpp)
+system_run(system_error_test.cpp)
+
+lib(boost_system_throw_test THROW_DYN_LINK throw_test.cpp)
+boost_test(SOURCES dynamic_link_test.cpp LINK_LIBRARIES boost_system_throw_test)
+
+system_run(initialization_test.cpp)
+system_run(header_only_test.cpp)
+
+boost_test(SOURCES config_test.cpp)
+
+system_run(std_interop_test.cpp)
+system_run(std_mismatch_test.cpp)
+
+lib(boost_system_single_instance_lib1 SINGLE_INSTANCE_DYN_LINK single_instance_1.cpp)
+lib(boost_system_single_instance_lib2 SINGLE_INSTANCE_DYN_LINK single_instance_2.cpp)
+
+system_run(single_instance_test.cpp single_instance_1.cpp single_instance_2.cpp)
+boost_test(SOURCES single_instance_test.cpp NAME single_instance_test_lib LINK_LIBRARIES boost_system_single_instance_lib1 boost_system_single_instance_lib2)
+
+system_run(before_main_test.cpp)
+system_run(constexpr_test.cpp)
+system_run(win32_hresult_test.cpp)
+
+system_run(error_category_test.cpp)
+system_run(generic_category_test.cpp)
+system_run(system_category_test.cpp)
+system_run(after_main_test.cpp)
+system_run(failed_test.cpp)
+system_run(failed_constexpr_test.cpp)
+
+boost_test(SOURCES warnings_test.cpp COMPILE_OPTIONS -Wall -Werror)
+
+lib(boost_system_std_single_instance_lib1 STD_SINGLE_INSTANCE_DYN_LINK std_single_instance_1.cpp)
+lib(boost_system_std_single_instance_lib2 STD_SINGLE_INSTANCE_DYN_LINK std_single_instance_2.cpp)
+
+system_run(std_single_instance_test.cpp std_single_instance_1.cpp std_single_instance_2.cpp)
+boost_test(SOURCES std_single_instance_test.cpp NAME std_single_instance_test_lib LINK_LIBRARIES boost_system_std_single_instance_lib1 boost_system_std_single_instance_lib2)
+
+boost_test(TYPE run SOURCES is_error_code_enum_test.cpp)
+boost_test(TYPE run SOURCES is_error_condition_enum_test.cpp)
+boost_test(TYPE run SOURCES errc_test.cpp)
+boost_test(TYPE run SOURCES errc_test2.cpp)
+boost_test(TYPE run SOURCES error_category_test2.cpp)
+boost_test(TYPE run SOURCES error_condition_test.cpp)
+boost_test(TYPE run SOURCES error_condition_test2.cpp)
+boost_test(TYPE run SOURCES generic_category_test2.cpp)
+boost_test(TYPE run SOURCES generic_category_test3.cpp)
+boost_test(TYPE run SOURCES system_category_test2.cpp)
+boost_test(TYPE run SOURCES system_category_test3.cpp)
+
+boost_test(TYPE run SOURCES windows_error_test.cpp)
+boost_test(TYPE run SOURCES cygwin_error_test.cpp)
+boost_test(TYPE run SOURCES linux_error_test.cpp)
+
+boost_test(TYPE link SOURCES errc_test3.cpp)
+
+boost_test(TYPE run SOURCES snprintf_test.cpp)
+
+boost_test(TYPE run SOURCES std_interop_test2.cpp)
+boost_test(TYPE run SOURCES std_interop_test3.cpp)
+boost_test(TYPE run SOURCES std_interop_test4.cpp)
+boost_test(TYPE run SOURCES std_interop_test5.cpp)
+boost_test(TYPE run SOURCES std_interop_test6.cpp)
+boost_test(TYPE run SOURCES std_interop_test7.cpp)
+boost_test(TYPE run SOURCES std_interop_test8.cpp)
+boost_test(TYPE run SOURCES std_interop_test9.cpp)
+
+boost_test(TYPE run SOURCES ec_location_test.cpp)
+
+boost_test(TYPE run SOURCES error_condition_test3.cpp)
+boost_test(TYPE run SOURCES error_code_test2.cpp)
+boost_test(TYPE run SOURCES system_error_test2.cpp)
+boost_test(TYPE run SOURCES std_interop_test10.cpp)
+
+boost_test(TYPE run SOURCES ec_location_test2.cpp)
+boost_test(TYPE run SOURCES ec_what_test.cpp)
+boost_test(TYPE run SOURCES system_error_test3.cpp)
+
+boost_test(TYPE run SOURCES std_interop_test11.cpp)
+
+boost_test(TYPE run SOURCES ec_wstream_test.cpp)
+
+boost_test(TYPE run SOURCES std_interop_test12.cpp)
+
+boost_test(TYPE run SOURCES errc_test4.cpp)
+
+boost_test(TYPE run SOURCES std_interop_test13.cpp)
+boost_test(TYPE run SOURCES std_interop_test14.cpp)
+
+boost_test(TYPE run SOURCES ec_location_test3.cpp)
+boost_test(TYPE run SOURCES ec_location_test4.cpp)
+
+# result
+
+set(BOOST_TEST_COMPILE_FEATURES cxx_std_11)
+
+boost_test(TYPE run SOURCES result_default_construct.cpp)
+boost_test(TYPE run SOURCES result_value_construct.cpp)
+boost_test(TYPE run SOURCES result_error_construct.cpp)
+boost_test(TYPE run SOURCES result_copy_construct.cpp)
+boost_test(TYPE run SOURCES result_move_construct.cpp)
+boost_test(TYPE run SOURCES result_copy_assign.cpp)
+boost_test(TYPE run SOURCES result_move_assign.cpp)
+boost_test(TYPE run SOURCES result_value_access.cpp)
+boost_test(TYPE run SOURCES result_error_access.cpp)
+boost_test(TYPE run SOURCES result_swap.cpp)
+boost_test(TYPE run SOURCES result_eq.cpp)
+boost_test(TYPE run SOURCES result_range_for.cpp)
+boost_test(TYPE run SOURCES result_value_construct2.cpp)
+boost_test(TYPE run SOURCES result_error_construct2.cpp)
+boost_test(TYPE run SOURCES result_convert_construct.cpp)

test/Jamfile.v2

@@ -1,43 +1,176 @@
 # Boost System Library test Jamfile
 
 # Copyright Beman Dawes 2003, 2006
+# Copyright 2017-2021 Peter Dimov
 
 # Distributed under the Boost Software License, Version 1.0.
 # See accompanying file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt
 
 # See library home page at http://www.boost.org/libs/system
 
-project
-    : requirements
-      <library>/boost/system//boost_system
-      <toolset>msvc:<asynch-exceptions>on
-    ;
+import testing ;
 
-   test-suite "system"
-       : [ run error_code_test.cpp
-           : # command line
-           : # input files
-           : # requirements
-                   <link>static
-         ]
-         [ run error_code_test.cpp
-           :  :  :  : error_code_test_dll
-         ]
-         [ run error_code_user_test.cpp
-           :  :  : <link>static
-         ]
-         [ run error_code_user_test.cpp
-           :  :  :  : error_code_user_test_dll
-         ]
-         [ run system_error_test.cpp
-           :  :  : <link>static
-         ]
-         [ run system_error_test.cpp
-            :  :  :  : system_error_test_dll
-         ]
-         [ run initialization_test.cpp
-         ]
-         [ run header_only_test.cpp
-           :  :  : <link>static
-         ]
-         ;
+project
+  : default-build
+
+    <warnings>extra
+
+  : requirements
+
+    <toolset>msvc:<warnings-as-errors>on
+    <toolset>gcc:<warnings-as-errors>on
+    <toolset>clang:<warnings-as-errors>on
+
+    <toolset>gcc-4.4:<cxxflags>-Wno-sign-compare
+  ;
+
+rule system-run ( sources + )
+{
+    local result ;
+
+    result += [ run $(sources) ] ;
+    result += [ run $(sources) : : : <library>/boost/system//boost_system <link>static : $(sources[1]:B)_static ] ;
+    result += [ run $(sources) : : : <library>/boost/system//boost_system <link>shared : $(sources[1]:B)_shared ] ;
+    result += [ run $(sources) : : : <define>BOOST_NO_ANSI_APIS : $(sources[1]:B)_no_ansi ] ;
+    result += [ run $(sources) : : : <define>BOOST_SYSTEM_USE_UTF8 : $(sources[1]:B)_utf8 ] ;
+
+    return $(result) ;
+}
+
+system-run error_code_test.cpp ;
+system-run error_code_user_test.cpp ;
+system-run system_error_test.cpp ;
+
+lib throw_test : throw_test.cpp : <link>shared:<define>THROW_DYN_LINK=1 ;
+
+run dynamic_link_test.cpp throw_test : : : <link>shared : throw_test_shared ;
+
+system-run initialization_test.cpp ;
+system-run header_only_test.cpp ;
+
+run config_test.cpp : : : <test-info>always_show_run_output ;
+
+system-run std_interop_test.cpp ;
+system-run std_mismatch_test.cpp ;
+
+lib single_instance_lib1 : single_instance_1.cpp : <link>shared:<define>SINGLE_INSTANCE_DYN_LINK ;
+lib single_instance_lib2 : single_instance_2.cpp : <link>shared:<define>SINGLE_INSTANCE_DYN_LINK ;
+
+system-run single_instance_test.cpp single_instance_1.cpp single_instance_2.cpp ;
+run single_instance_test.cpp single_instance_lib1 single_instance_lib2 : : : <link>static : single_instance_lib_static ;
+run single_instance_test.cpp single_instance_lib1 single_instance_lib2 : : : <link>shared : single_instance_lib_shared ;
+
+system-run before_main_test.cpp ;
+
+run-fail throws_assign_fail.cpp : : :
+    # GCC 12 catches this at compile time with a warning
+    <toolset>gcc,<variant>release:<build>no ;
+
+system-run constexpr_test.cpp ;
+system-run win32_hresult_test.cpp ;
+
+system-run error_category_test.cpp ;
+system-run generic_category_test.cpp ;
+system-run system_category_test.cpp ;
+system-run after_main_test.cpp ;
+system-run failed_test.cpp ;
+system-run failed_constexpr_test.cpp ;
+
+# Quick (CI) test
+run quick.cpp ;
+
+run warnings_test.cpp
+  : : : <warnings>pedantic
+    <toolset>msvc:<warnings-as-errors>on
+    <toolset>gcc:<warnings-as-errors>on
+    <toolset>clang:<warnings-as-errors>on ;
+
+lib std_single_instance_lib1 : std_single_instance_1.cpp : <link>shared:<define>STD_SINGLE_INSTANCE_DYN_LINK ;
+lib std_single_instance_lib2 : std_single_instance_2.cpp : <link>shared:<define>STD_SINGLE_INSTANCE_DYN_LINK ;
+
+system-run std_single_instance_test.cpp std_single_instance_1.cpp std_single_instance_2.cpp ;
+run std_single_instance_test.cpp std_single_instance_lib1 std_single_instance_lib2 : : : <link>static : std_single_instance_lib_static ;
+run std_single_instance_test.cpp std_single_instance_lib1 std_single_instance_lib2 : : : <link>shared <define>STD_SINGLE_INSTANCE_SHARED : std_single_instance_lib_shared ;
+
+run is_error_code_enum_test.cpp ;
+run is_error_condition_enum_test.cpp ;
+run errc_test.cpp ;
+run errc_test2.cpp ;
+run error_category_test2.cpp ;
+run error_condition_test.cpp ;
+run error_condition_test2.cpp ;
+run generic_category_test2.cpp ;
+run generic_category_test3.cpp ;
+run system_category_test2.cpp ;
+run system_category_test3.cpp ;
+
+run windows_error_test.cpp ;
+run cygwin_error_test.cpp ;
+run linux_error_test.cpp ;
+
+link errc_test3.cpp ;
+
+run snprintf_test.cpp ;
+
+run std_interop_test2.cpp ;
+run std_interop_test3.cpp ;
+run std_interop_test4.cpp ;
+run std_interop_test5.cpp
+  : : :
+  # crash on xenial, but the real g++ 4.8 on both centos 7 and trusty works
+  <toolset>gcc-4.8:<build>no
+  <toolset>gcc-4.9:<build>no
+  ;
+
+run std_interop_test6.cpp ;
+run std_interop_test7.cpp ;
+run std_interop_test8.cpp ;
+run std_interop_test9.cpp ;
+
+run ec_location_test.cpp ;
+
+run error_condition_test3.cpp ;
+run error_code_test2.cpp ;
+run system_error_test2.cpp ;
+run std_interop_test10.cpp ;
+
+run ec_location_test2.cpp ;
+run ec_what_test.cpp ;
+run system_error_test3.cpp ;
+
+run std_interop_test11.cpp ;
+
+run ec_wstream_test.cpp ;
+
+run std_interop_test12.cpp ;
+
+run errc_test4.cpp ;
+
+run std_interop_test13.cpp ;
+run std_interop_test14.cpp ;
+
+run ec_location_test3.cpp ;
+run ec_location_test4.cpp ;
+
+# result
+
+import ../../config/checks/config : requires ;
+
+CPP11 = [ requires cxx11_variadic_templates cxx11_template_aliases cxx11_decltype cxx11_constexpr cxx11_noexcept ] <toolset>gcc-4.7:<build>no ;
+
+run result_default_construct.cpp : : : $(CPP11) ;
+run result_value_construct.cpp : : : $(CPP11) ;
+run result_error_construct.cpp : : : $(CPP11) ;
+run result_copy_construct.cpp : : : $(CPP11) ;
+run result_move_construct.cpp : : : $(CPP11) ;
+run result_copy_assign.cpp : : : $(CPP11) ;
+run result_move_assign.cpp : : : $(CPP11) ;
+run result_value_access.cpp : : : $(CPP11) ;
+run result_error_access.cpp : : : $(CPP11) ;
+run result_swap.cpp : : : $(CPP11) <toolset>gcc-10:<cxxflags>"-Wno-maybe-uninitialized" ;
+run result_eq.cpp : : : $(CPP11) ;
+run result_range_for.cpp : : : $(CPP11) ;
+run result_value_construct2.cpp : : : $(CPP11) ;
+run result_error_construct2.cpp : : : $(CPP11) ;
+run result_errc_construct.cpp : : : $(CPP11) ;
+run result_convert_construct.cpp : : : $(CPP11) ;

test/after_main_test.cpp

@@ -0,0 +1,37 @@
+
+// Copyright 2018 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+
+#include <boost/system/error_code.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/core/quick_exit.hpp>
+#include <boost/config.hpp>
+#include <cerrno>
+
+#if defined(BOOST_MSVC)
+# pragma warning(disable: 4722) // Z::~Z never returns
+#endif
+
+using namespace boost::system;
+
+struct Z
+{
+    ~Z()
+    {
+        BOOST_TEST_CSTR_EQ( generic_category().name(), "generic" );
+        BOOST_TEST_CSTR_EQ( system_category().name(), "system" );
+
+        boost::quick_exit( boost::report_errors() );
+    }
+};
+
+static Z z;
+
+static error_code e1( 1, system_category() );
+static error_code e2( ENOENT, generic_category() );
+
+int main()
+{
+    (void)e1;
+    (void)e2;
+}

test/before_main_test.cpp

@@ -0,0 +1,30 @@
+
+// Copyright 2018 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+
+#include <boost/system/error_code.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cerrno>
+
+using namespace boost::system;
+
+static error_code e1( 1, system_category() );
+static std::string m1 = e1.message();
+
+static error_code e2( ENOENT, generic_category() );
+static std::string m2 = e2.message();
+
+int main()
+{
+    error_code e1_( 1, system_category() );
+
+    BOOST_TEST_EQ( e1, e1_ );
+    BOOST_TEST_EQ( m1, e1_.message() );
+
+    error_code e2_( ENOENT, generic_category() );
+
+    BOOST_TEST_EQ( e2, e2_ );
+    BOOST_TEST_EQ( m2, e2_.message() );
+
+    return boost::report_errors();
+}

test/cmake_install_test/CMakeLists.txt

@@ -0,0 +1,17 @@
+# Copyright 2018, 2019 Peter Dimov
+# Distributed under the Boost Software License, Version 1.0.
+# See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt
+
+cmake_minimum_required(VERSION 3.5...3.16)
+
+project(cmake_install_test LANGUAGES CXX)
+
+find_package(boost_system REQUIRED)
+
+add_executable(main main.cpp)
+target_link_libraries(main Boost::system)
+
+enable_testing()
+add_test(main main)
+
+add_custom_target(check COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure -C $<CONFIG>)

test/cmake_install_test/main.cpp

@@ -0,0 +1,44 @@
+// Copyright 2017, 2021 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+// See library home page at http://www.boost.org/libs/system
+
+#include <boost/system.hpp>
+#include <cassert>
+#include <cerrno>
+
+#define BOOST_TEST(expr) assert(expr)
+#define BOOST_TEST_EQ(x1, x2) assert((x1)==(x2))
+
+int main()
+{
+    boost::system::error_category const & bt = boost::system::generic_category();
+
+    int ev = ENOENT;
+
+    boost::system::error_code bc( ev, bt );
+
+    BOOST_TEST_EQ( bc.value(), ev );
+    BOOST_TEST_EQ( &bc.category(), &bt );
+
+    boost::system::error_condition bn = bt.default_error_condition( ev );
+
+    BOOST_TEST_EQ( bn.value(), ev );
+    BOOST_TEST_EQ( &bn.category(), &bt );
+
+    BOOST_TEST( bt.equivalent( ev, bn ) );
+
+    BOOST_TEST( bc == bn );
+
+    boost::system::error_code bc2 = make_error_code( boost::system::errc::no_such_file_or_directory );
+
+    BOOST_TEST_EQ( bc2, bc );
+    BOOST_TEST_EQ( bc2.value(), ev );
+    BOOST_TEST_EQ( &bc.category(), &bt );
+
+    boost::system::system_error x( bc, "prefix" );
+
+    BOOST_TEST_EQ( x.code(), bc );
+    BOOST_TEST_EQ( std::string( x.what() ), "prefix: " + bc.what() );
+}

test/cmake_subdir_test/CMakeLists.txt

@@ -0,0 +1,26 @@
+# Copyright 2018-2021 Peter Dimov
+# Distributed under the Boost Software License, Version 1.0.
+# See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt
+
+cmake_minimum_required(VERSION 3.5...3.20)
+
+project(cmake_subdir_test LANGUAGES CXX)
+
+add_subdirectory(../.. boostorg/system)
+add_subdirectory(../../../assert boostorg/assert)
+add_subdirectory(../../../config boostorg/config)
+add_subdirectory(../../../core boostorg/core)
+add_subdirectory(../../../mp11 boostorg/mp11)
+add_subdirectory(../../../predef boostorg/predef)
+add_subdirectory(../../../static_assert boostorg/static_assert)
+add_subdirectory(../../../throw_exception boostorg/throw_exception)
+add_subdirectory(../../../variant2 boostorg/variant2)
+add_subdirectory(../../../winapi boostorg/winapi)
+
+add_executable(quick ../quick.cpp)
+target_link_libraries(quick Boost::system Boost::core)
+
+enable_testing()
+add_test(quick quick)
+
+add_custom_target(check COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure --no-tests=error -C $<CONFIG>)

test/config_test.cpp

@@ -0,0 +1,65 @@
+//  error_code_test.cpp  ---------------------------------------------------------------//
+
+//  Copyright Beman Dawes 2014
+
+//  Distributed under the Boost Software License, Version 1.0.
+//  See http://www.boost.org/LICENSE_1_0.txt
+
+//  See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/config.hpp>
+#include <iostream>
+
+using std::cout;
+using std::endl;
+
+int main()
+{
+#ifdef BOOST_WINDOWS_API
+  std::cout << "BOOST_WINDOWS_API is defined" << std::endl;
+#else
+  std::cout << "BOOST_WINDOWS_API is not defined" << std::endl;
+#endif
+#ifdef _MSC_VER
+  std::cout << "_MSC_VER is defined as " <<  _MSC_VER << std::endl;
+#else
+  std::cout << "_MSC_VER is not defined" << std::endl;
+#endif
+#ifdef  __CYGWIN__
+  std::cout << "__CYGWIN__ is defined" << std::endl;
+#else
+  std::cout << "__CYGWIN__ is not defined" << std::endl;
+#endif
+#ifdef __MINGW32__
+  std::cout << "__MINGW32__ is defined" << std::endl;
+#else
+  std::cout << "__MINGW32__ is not defined" << std::endl;
+#endif
+#ifdef BOOST_POSIX_API
+  std::cout << "BOOST_POSIX_API is defined" << std::endl;
+#else
+  std::cout << "BOOST_POSIX_API is not defined" << std::endl;
+#endif
+#ifdef BOOST_PLAT_WINDOWS_DESKTOP
+  std::cout << "BOOST_PLAT_WINDOWS_DESKTOP is defined as "
+    << BOOST_PLAT_WINDOWS_DESKTOP << std::endl;
+#else
+  std::cout << "BOOST_PLAT_WINDOWS_DESKTOP is not defined" << std::endl;
+#endif
+#ifdef BOOST_NO_ANSI_APIS
+  std::cout << "BOOST_NO_ANSI_APIS is defined" << std::endl;
+#else
+  std::cout << "BOOST_NO_ANSI_APIS is not defined" << std::endl;
+#endif
+#ifdef BOOST_NO_CXX11_NOEXCEPT
+  std::cout << "BOOST_NO_CXX11_NOEXCEPT is defined" << std::endl;
+#else
+  std::cout << "BOOST_NO_CXX11_NOEXCEPT is not defined" << std::endl;
+#endif
+#ifdef BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS
+  std::cout << "BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS is defined" << std::endl;
+#else
+  std::cout << "BOOST_NO_CXX11_EXPLICIT_CONVERSION_OPERATORS is not defined" << std::endl;
+#endif
+  return 0;
+}

test/constexpr_test.cpp

@@ -0,0 +1,68 @@
+
+// Copyright 2018 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+
+#include <boost/system/error_code.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/config/pragma_message.hpp>
+#include <boost/static_assert.hpp>
+#include <boost/config.hpp>
+#include <boost/config/workaround.hpp>
+
+#if !defined(BOOST_SYSTEM_HAS_CONSTEXPR)
+
+BOOST_PRAGMA_MESSAGE("Skipping constexpr test, BOOST_SYSTEM_HAS_CONSTEXPR isn't defined")
+int main() {}
+
+#else
+
+using namespace boost::system;
+
+constexpr error_code e1( 1, system_category() );
+
+BOOST_STATIC_ASSERT( e1.value() == 1 );
+BOOST_STATIC_ASSERT( e1.category() == system_category() );
+BOOST_STATIC_ASSERT( e1 );
+BOOST_STATIC_ASSERT( e1 == e1 );
+
+constexpr error_code e2( 2, generic_category() );
+
+BOOST_STATIC_ASSERT( e2.value() == 2 );
+BOOST_STATIC_ASSERT( e2.category() == generic_category() );
+BOOST_STATIC_ASSERT( e2 );
+BOOST_STATIC_ASSERT( e2 == e2 );
+
+#if !BOOST_WORKAROUND(BOOST_GCC, < 80200)
+
+BOOST_STATIC_ASSERT( e1 != e2 );
+
+#endif
+
+constexpr error_code e3;
+
+BOOST_STATIC_ASSERT( e3.value() == 0 );
+BOOST_STATIC_ASSERT( e3.category() == system_category() );
+BOOST_STATIC_ASSERT( !e3 );
+BOOST_STATIC_ASSERT( e3 == e3 );
+
+#if !BOOST_WORKAROUND(BOOST_GCC, < 80200)
+
+BOOST_STATIC_ASSERT( e1 != e3 );
+
+#endif
+
+int main()
+{
+    error_code e1_( 1, system_category() );
+    BOOST_TEST_EQ( e1, e1_ );
+
+    error_code e2_( 2, generic_category() );
+    BOOST_TEST_EQ( e2, e2_ );
+
+    error_code e3_;
+    BOOST_TEST_EQ( e3, e3_ );
+
+    return boost::report_errors();
+}
+
+#endif

test/cygwin_error_test.cpp

@@ -0,0 +1,29 @@
+// Copyright 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/cygwin_error.hpp>
+#include <boost/config/pragma_message.hpp>
+
+#if !defined(__CYGWIN__)
+
+BOOST_PRAGMA_MESSAGE( "Skipping test, __CYGWIN__ is not defined" )
+int main() {}
+
+#else
+
+#include <boost/core/lightweight_test.hpp>
+
+int main()
+{
+    namespace sys = boost::system;
+
+    sys::error_code ec = sys::cygwin_error::no_package;
+
+    BOOST_TEST_EQ( ec, sys::cygwin_error::no_package );
+    BOOST_TEST_EQ( ec, sys::error_code( ENOPKG, sys::system_category() ) );
+
+    return boost::report_errors();
+}
+
+#endif

test/dynamic_link_test.cpp

@@ -0,0 +1,47 @@
+//  dynamic_link_test.cpp  -------------------------------------------------------------//
+
+//  Copyright Beman Dawes 2010
+
+//  Distributed under the Boost Software License, Version 1.0.
+//  See www.boost.org/LICENSE_1_0.txt
+
+//  Library home page is www.boost.org/libs/system
+
+//--------------------------------------------------------------------------------------// 
+
+//  Dynamic link libraries (DLL's), also know as dynamic shared objects (DSO's),
+//  can cause symbol visability problems unless carefully configured. One of the
+//  manifestations, particularly with GCC, is that a system_error exception thrown from
+//  a DLL or DSO is not caught.
+//
+//  The purpose of this program is to test for that error.
+
+//--------------------------------------------------------------------------------------// 
+
+#include <boost/system/system_error.hpp>
+#include <iostream>
+
+void throw_test();
+
+int main()
+{
+  try
+  {
+    throw_test();
+  }
+  catch (const boost::system::system_error& ex)
+  {
+    std::cout << "  caught boost::system::system_error as expected\n";
+    std::cout << "  what() reports " << ex.what() << '\n';
+    return 0;
+  }
+  catch (const std::runtime_error& ex)
+  {
+    std::cout << "  error: caught std::runtime_error instead of boost::system::system_error\n";
+    std::cout << "  what() reports " << ex.what() << '\n';
+    return 1;
+  }
+
+  std::cout << "  error: failed to catch boost::system::system_error\n";
+  return 1;
+}

test/ec_location_test.cpp

@@ -0,0 +1,116 @@
+// Copyright 2021 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cerrno>
+
+int main()
+{
+    int const val = ENOENT;
+    boost::system::error_category const & cat = boost::system::generic_category();
+
+    {
+        boost::system::error_code ec( val, cat );
+
+        BOOST_TEST_EQ( ec.value(), val );
+        BOOST_TEST_EQ( &ec.category(), &cat );
+
+        BOOST_TEST( ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+    }
+
+    {
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        boost::system::error_code ec( val, cat, &loc );
+
+        BOOST_TEST_EQ( ec.value(), val );
+        BOOST_TEST_EQ( &ec.category(), &cat );
+
+        BOOST_TEST( ec.failed() );
+
+        BOOST_TEST( ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 27 );
+    }
+
+    {
+        boost::system::error_code ec;
+
+        BOOST_TEST_EQ( ec.value(), 0 );
+        BOOST_TEST_EQ( &ec.category(), &boost::system::system_category() );
+
+        BOOST_TEST( !ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec = boost::system::error_code( val, cat, &loc );
+
+        BOOST_TEST_EQ( ec.value(), val );
+        BOOST_TEST_EQ( &ec.category(), &cat );
+
+        BOOST_TEST( ec.failed() );
+
+        BOOST_TEST( ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 51 );
+    }
+
+    {
+        boost::system::error_code ec;
+
+        BOOST_TEST_EQ( ec.value(), 0 );
+        BOOST_TEST_EQ( &ec.category(), &boost::system::system_category() );
+
+        BOOST_TEST( !ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec.assign( val, cat, &loc );
+
+        BOOST_TEST_EQ( ec.value(), val );
+        BOOST_TEST_EQ( &ec.category(), &cat );
+
+        BOOST_TEST( ec.failed() );
+
+        BOOST_TEST( ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 75 );
+    }
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    {
+        std::error_code e2( val, std::generic_category() );
+
+        boost::system::error_code ec( e2 );
+
+        BOOST_TEST( ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec.assign( val, cat, &loc );
+
+        BOOST_TEST_EQ( ec.value(), val );
+        BOOST_TEST_EQ( &ec.category(), &cat );
+
+        BOOST_TEST( ec.failed() );
+
+        BOOST_TEST( ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 100 );
+    }
+
+#endif
+
+    return boost::report_errors();
+}

test/ec_location_test2.cpp

@@ -0,0 +1,287 @@
+// Copyright 2021 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cerrno>
+
+namespace sys = boost::system;
+
+enum E
+{
+    none = 0,
+    einval = EINVAL
+};
+
+namespace boost
+{
+namespace system
+{
+
+template<> struct is_error_code_enum< ::E >
+{
+    static const bool value = true;
+};
+
+} // namespace system
+} // namespace boost
+
+sys::error_code make_error_code( E e )
+{
+    return e == 0? sys::error_code(): sys::error_code( e, sys::generic_category() );
+}
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+enum E2
+{
+    e2inval = EINVAL
+};
+
+namespace boost
+{
+namespace system
+{
+
+template<> struct is_error_code_enum< ::E2 >
+{
+    static const bool value = true;
+};
+
+} // namespace system
+} // namespace boost
+
+std::error_code make_error_code( E2 e )
+{
+    return std::error_code( e, std::generic_category() );
+}
+
+#endif
+
+int main()
+{
+    {
+        sys::error_code ec( einval );
+
+        BOOST_TEST_EQ( ec.value(), EINVAL );
+        BOOST_TEST_EQ( &ec.category(), &sys::generic_category() );
+
+        BOOST_TEST( ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+    }
+
+    {
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        sys::error_code ec( einval, &loc );
+
+        BOOST_TEST_EQ( ec.value(), EINVAL );
+        BOOST_TEST_EQ( &ec.category(), &sys::generic_category() );
+
+        BOOST_TEST( ec.failed() );
+
+        BOOST_TEST( ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 77 );
+    }
+
+    {
+        sys::error_code ec( none );
+
+        BOOST_TEST_EQ( ec.value(), 0 );
+        BOOST_TEST_EQ( &ec.category(), &sys::system_category() );
+
+        BOOST_TEST( !ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+    }
+
+    {
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        sys::error_code ec( none, &loc );
+
+        BOOST_TEST_EQ( ec.value(), 0 );
+        BOOST_TEST_EQ( &ec.category(), &sys::system_category() );
+
+        BOOST_TEST( !ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+    }
+
+    {
+        sys::error_code ec;
+
+        BOOST_TEST_EQ( ec.value(), 0 );
+        BOOST_TEST_EQ( &ec.category(), &sys::system_category() );
+
+        BOOST_TEST( !ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec = sys::error_code( einval, &loc );
+
+        BOOST_TEST_EQ( ec.value(), EINVAL );
+        BOOST_TEST_EQ( &ec.category(), &sys::generic_category() );
+
+        BOOST_TEST( ec.failed() );
+
+        BOOST_TEST( ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 127 );
+    }
+
+    {
+        sys::error_code ec;
+
+        BOOST_TEST_EQ( ec.value(), 0 );
+        BOOST_TEST_EQ( &ec.category(), &sys::system_category() );
+
+        BOOST_TEST( !ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec = sys::error_code( none, &loc );
+
+        BOOST_TEST_EQ( ec.value(), 0 );
+        BOOST_TEST_EQ( &ec.category(), &sys::system_category() );
+
+        BOOST_TEST( !ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+    }
+
+    {
+        sys::error_code ec;
+
+        BOOST_TEST_EQ( ec.value(), 0 );
+        BOOST_TEST_EQ( &ec.category(), &sys::system_category() );
+
+        BOOST_TEST( !ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec.assign( einval, &loc );
+
+        BOOST_TEST_EQ( ec.value(), EINVAL );
+        BOOST_TEST_EQ( &ec.category(), &sys::generic_category() );
+
+        BOOST_TEST( ec.failed() );
+
+        BOOST_TEST( ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 175 );
+    }
+
+    {
+        sys::error_code ec;
+
+        BOOST_TEST_EQ( ec.value(), 0 );
+        BOOST_TEST_EQ( &ec.category(), &sys::system_category() );
+
+        BOOST_TEST( !ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec.assign( none, &loc );
+
+        BOOST_TEST_EQ( ec.value(), 0 );
+        BOOST_TEST_EQ( &ec.category(), &sys::system_category() );
+
+        BOOST_TEST( !ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+    }
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    {
+        sys::error_code ec( e2inval );
+
+        BOOST_TEST_EQ( ec, std::error_code( EINVAL, std::generic_category() ) );
+
+        BOOST_TEST( ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+    }
+
+    {
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        sys::error_code ec( e2inval, &loc );
+
+        BOOST_TEST_EQ( ec, std::error_code( EINVAL, std::generic_category() ) );
+
+        BOOST_TEST( ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+    }
+
+    {
+        sys::error_code ec;
+
+        BOOST_TEST_EQ( ec.value(), 0 );
+        BOOST_TEST_EQ( &ec.category(), &sys::system_category() );
+
+        BOOST_TEST( !ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec = sys::error_code( e2inval, &loc );
+
+        BOOST_TEST_EQ( ec, std::error_code( EINVAL, std::generic_category() ) );
+
+        BOOST_TEST( ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+    }
+
+    {
+        sys::error_code ec;
+
+        BOOST_TEST_EQ( ec.value(), 0 );
+        BOOST_TEST_EQ( &ec.category(), &sys::system_category() );
+
+        BOOST_TEST( !ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec.assign( e2inval, &loc );
+
+        BOOST_TEST_EQ( ec, std::error_code( EINVAL, std::generic_category() ) );
+
+        BOOST_TEST( ec.failed() );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location().line(), 0 );
+    }
+
+#endif
+
+    return boost::report_errors();
+}

test/ec_location_test3.cpp

@@ -0,0 +1,90 @@
+// Copyright 2021, 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cerrno>
+
+int main()
+{
+    int const val = ENOENT;
+    boost::system::error_category const & cat = boost::system::generic_category();
+
+    {
+        boost::system::error_code ec;
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        boost::system::error_code ec2( ec, &loc );
+
+        BOOST_TEST_EQ( ec2, ec );
+
+        BOOST_TEST( !ec2.has_location() );
+        BOOST_TEST_EQ( ec2.location(), boost::source_location() );
+
+        boost::system::error_code ec3( ec2, 0 );
+
+        BOOST_TEST_EQ( ec3, ec2 );
+
+        BOOST_TEST( !ec3.has_location() );
+        BOOST_TEST_EQ( ec3.location(), boost::source_location() );
+    }
+
+    {
+        boost::system::error_code ec( val, cat );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        boost::system::error_code ec2( ec, &loc );
+
+        BOOST_TEST_EQ( ec2, ec );
+
+        BOOST_TEST( ec2.has_location() );
+        BOOST_TEST_EQ( ec2.location(), loc );
+
+        boost::system::error_code ec3( ec2, 0 );
+
+        BOOST_TEST_EQ( ec3, ec2 );
+
+        BOOST_TEST( !ec3.has_location() );
+        BOOST_TEST_EQ( ec3.location(), boost::source_location() );
+    }
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    {
+        std::error_code e2( val, std::generic_category() );
+
+        boost::system::error_code ec( e2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        boost::system::error_code ec2( ec, &loc );
+
+        BOOST_TEST_EQ( ec2, ec );
+
+        BOOST_TEST( !ec2.has_location() );
+        BOOST_TEST_EQ( ec2.location(), boost::source_location() );
+
+        boost::system::error_code ec3( ec2, 0 );
+
+        BOOST_TEST_EQ( ec3, ec2 );
+
+        BOOST_TEST( !ec3.has_location() );
+        BOOST_TEST_EQ( ec3.location(), boost::source_location() );
+    }
+
+#endif
+
+    return boost::report_errors();
+}

test/ec_location_test4.cpp

@@ -0,0 +1,93 @@
+// Copyright 2021, 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cerrno>
+
+int main()
+{
+    int const val = ENOENT;
+    boost::system::error_category const & cat = boost::system::generic_category();
+
+    {
+        boost::system::error_code ec;
+        boost::system::error_code ec2( ec );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec.assign( ec, &loc );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        ec.assign( ec, 0 );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+    }
+
+    {
+        boost::system::error_code ec( val, cat );
+        boost::system::error_code ec2( ec );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec.assign( ec, &loc );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), loc );
+
+        ec.assign( ec, 0 );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+    }
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    {
+        std::error_code e2( val, std::generic_category() );
+
+        boost::system::error_code ec( e2 );
+        boost::system::error_code ec2( ec );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec.assign( ec, &loc );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        ec.assign( ec, 0 );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+    }
+
+#endif
+
+    return boost::report_errors();
+}

test/ec_what_test.cpp

@@ -0,0 +1,91 @@
+// Copyright 2020, 2021 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/error_code.hpp>
+#include <boost/system/generic_category.hpp>
+#include <boost/system/system_category.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+namespace sys = boost::system;
+
+int main()
+{
+    {
+        sys::error_code ec;
+
+        BOOST_TEST_EQ( ec.value(), 0 );
+        BOOST_TEST( ec.category() == sys::system_category() );
+
+        BOOST_TEST_EQ( ec.what(), ec.message() + " [system:0]" );
+    }
+
+    {
+        sys::error_code ec( 5, sys::generic_category() );
+
+        BOOST_TEST_EQ( ec.value(), 5 );
+        BOOST_TEST( ec.category() == sys::generic_category() );
+
+        BOOST_TEST_EQ( ec.what(), ec.message() + " [generic:5]" );
+    }
+
+    {
+        sys::error_code ec( 5, sys::system_category() );
+
+        BOOST_TEST_EQ( ec.value(), 5 );
+        BOOST_TEST( ec.category() == sys::system_category() );
+
+        BOOST_TEST_EQ( ec.what(), ec.message() + " [system:5]" );
+    }
+
+    {
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        sys::error_code ec( 5, sys::generic_category(), &loc );
+
+        BOOST_TEST_EQ( ec.value(), 5 );
+        BOOST_TEST( ec.category() == sys::generic_category() );
+        BOOST_TEST_EQ( &ec.location(), &loc );
+
+        BOOST_TEST_EQ( ec.what(), ec.message() + " [generic:5 at " + loc.to_string() + "]" );
+    }
+
+    {
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        sys::error_code ec( 5, sys::system_category(), &loc );
+
+        BOOST_TEST_EQ( ec.value(), 5 );
+        BOOST_TEST( ec.category() == sys::system_category() );
+        BOOST_TEST_EQ( &ec.location(), &loc );
+
+        BOOST_TEST_EQ( ec.what(), ec.message() + " [system:5 at " + loc.to_string() + "]" );
+    }
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    {
+        std::error_code ec;
+        sys::error_code ec2( ec );
+
+        BOOST_TEST_EQ( ec2.what(), ec2.message() + " [std:system:0]" );
+    }
+
+    {
+        std::error_code ec( 5, std::generic_category() );
+        sys::error_code ec2( ec );
+
+        BOOST_TEST_EQ( ec2.what(), ec2.message() + " [std:generic:5]" );
+    }
+
+    {
+        std::error_code ec( 5, std::system_category() );
+        sys::error_code ec2( ec );
+
+        BOOST_TEST_EQ( ec2.what(), ec2.message() + " [std:system:5]" );
+    }
+
+#endif
+
+    return boost::report_errors();
+}

test/ec_wstream_test.cpp

@@ -0,0 +1,21 @@
+// Copyright 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/error_code.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <sstream>
+
+namespace sys = boost::system;
+
+int main()
+{
+    {
+        std::wostringstream os;
+        os << sys::error_code();
+
+        BOOST_TEST( os.str() == L"system:0" );
+    }
+
+    return boost::report_errors();
+}

test/errc_test.cpp

@@ -0,0 +1,18 @@
+// Copyright 2020 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/errc.hpp>
+#include <boost/system/is_error_condition_enum.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+int main()
+{
+    BOOST_TEST_EQ( static_cast<int>( boost::system::errc::success ), 0 );
+    BOOST_TEST_EQ( static_cast<int>( boost::system::errc::no_such_file_or_directory ), ENOENT );
+    BOOST_TEST_EQ( static_cast<int>( boost::system::errc::address_family_not_supported ), EAFNOSUPPORT );
+
+    BOOST_TEST( boost::system::is_error_condition_enum< boost::system::errc::errc_t >::value );
+
+    return boost::report_errors();
+}

test/errc_test2.cpp

@@ -0,0 +1,20 @@
+// Copyright 2020 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/errc.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+int main()
+{
+    BOOST_TEST_EQ( make_error_code( boost::system::errc::success ).value(), 0 );
+    BOOST_TEST_EQ( make_error_condition( boost::system::errc::success ).value(), 0 );
+
+    BOOST_TEST_EQ( make_error_code( boost::system::errc::no_such_file_or_directory ).value(), ENOENT );
+    BOOST_TEST_EQ( make_error_condition( boost::system::errc::no_such_file_or_directory ).value(), ENOENT );
+
+    BOOST_TEST_EQ( make_error_code( boost::system::errc::address_family_not_supported ).value(), EAFNOSUPPORT );
+    BOOST_TEST_EQ( make_error_condition( boost::system::errc::address_family_not_supported ).value(), EAFNOSUPPORT );
+
+    return boost::report_errors();
+}

test/errc_test3.cpp

@@ -0,0 +1,34 @@
+// Copyright 2021 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/errc.hpp>
+
+int main()
+{
+    make_error_code( boost::system::errc::success ).value();
+    make_error_code( boost::system::errc::success ).category();
+    make_error_code( boost::system::errc::success ).default_error_condition();
+    make_error_code( boost::system::errc::success ).message();
+    make_error_code( boost::system::errc::success ).failed();
+    make_error_code( boost::system::errc::success ).clear();
+
+    make_error_condition( boost::system::errc::success ).value();
+    make_error_condition( boost::system::errc::success ).category();
+    make_error_condition( boost::system::errc::success ).message();
+    make_error_condition( boost::system::errc::success ).failed();
+    make_error_condition( boost::system::errc::success ).clear();
+
+    make_error_code( boost::system::errc::no_such_file_or_directory ).value();
+    make_error_code( boost::system::errc::no_such_file_or_directory ).category();
+    make_error_code( boost::system::errc::no_such_file_or_directory ).default_error_condition();
+    make_error_code( boost::system::errc::no_such_file_or_directory ).message();
+    make_error_code( boost::system::errc::no_such_file_or_directory ).failed();
+    make_error_code( boost::system::errc::no_such_file_or_directory ).clear();
+
+    make_error_condition( boost::system::errc::no_such_file_or_directory ).value();
+    make_error_condition( boost::system::errc::no_such_file_or_directory ).category();
+    make_error_condition( boost::system::errc::no_such_file_or_directory ).message();
+    make_error_condition( boost::system::errc::no_such_file_or_directory ).failed();
+    make_error_condition( boost::system::errc::no_such_file_or_directory ).clear();
+}

test/errc_test4.cpp

@@ -0,0 +1,17 @@
+// Copyright 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/errc.hpp>
+#include <boost/assert/source_location.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+int main()
+{
+    BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+    BOOST_TEST( make_error_code( boost::system::errc::no_such_file_or_directory, &loc ).has_location() );
+    BOOST_TEST_EQ( make_error_code( boost::system::errc::no_such_file_or_directory, &loc ).location().to_string(), loc.to_string() );
+
+    return boost::report_errors();
+}

test/error_category_test.cpp

@@ -0,0 +1,82 @@
+
+// Copyright 2018 Peter Dimov.
+//
+// Distributed under the Boost Software License, Version 1.0.
+//
+// See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt
+
+// See library home page at http://www.boost.org/libs/system
+
+// Avoid spurious VC++ warnings
+# define _CRT_SECURE_NO_WARNINGS
+
+#include <boost/system/error_code.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cstdio>
+
+//
+
+namespace sys = boost::system;
+
+class user_category: public sys::error_category
+{
+public:
+
+    virtual const char * name() const BOOST_NOEXCEPT
+    {
+        return "user";
+    }
+
+    virtual std::string message( int ev ) const
+    {
+        char buffer[ 256 ];
+        std::sprintf( buffer, "user message %d", ev );
+
+        return buffer;
+    }
+
+    using sys::error_category::message;
+};
+
+static user_category s_cat_1;
+static user_category s_cat_2;
+
+int main()
+{
+    // default_error_condition
+
+    BOOST_TEST( s_cat_1.default_error_condition( 1 ) == sys::error_condition( 1, s_cat_1 ) );
+    BOOST_TEST( s_cat_2.default_error_condition( 2 ) == sys::error_condition( 2, s_cat_2 ) );
+
+    // equivalent
+
+    BOOST_TEST( s_cat_1.equivalent( 1, sys::error_condition( 1, s_cat_1 ) ) );
+    BOOST_TEST( !s_cat_1.equivalent( 1, sys::error_condition( 2, s_cat_1 ) ) );
+    BOOST_TEST( !s_cat_1.equivalent( 1, sys::error_condition( 2, s_cat_2 ) ) );
+
+    // the other equivalent
+
+    BOOST_TEST( s_cat_1.equivalent( sys::error_code( 1, s_cat_1 ), 1 ) );
+    BOOST_TEST( !s_cat_1.equivalent( sys::error_code( 1, s_cat_1 ), 2 ) );
+    BOOST_TEST( !s_cat_1.equivalent( sys::error_code( 1, s_cat_2 ), 1 ) );
+
+    // message
+
+    {
+        char buffer[ 256 ];
+        BOOST_TEST_CSTR_EQ( s_cat_1.message( 1, buffer, sizeof( buffer ) ), s_cat_1.message( 1 ).c_str() );
+    }
+
+    {
+        char buffer[ 4 ];
+        BOOST_TEST_CSTR_EQ( s_cat_1.message( 1, buffer, sizeof( buffer ) ), "use" );
+    }
+
+    // ==
+
+    BOOST_TEST_NOT( s_cat_1 == s_cat_2 );
+    BOOST_TEST( s_cat_1 != s_cat_2 );
+
+    return boost::report_errors();
+}

test/error_category_test2.cpp

@@ -0,0 +1,79 @@
+
+// Copyright 2018, 2020 Peter Dimov.
+//
+// Distributed under the Boost Software License, Version 1.0.
+//
+// See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt
+
+// See library home page at http://www.boost.org/libs/system
+
+// Avoid spurious VC++ warnings
+#define _CRT_SECURE_NO_WARNINGS
+
+#include <boost/system/error_category.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cstdio>
+
+//
+
+namespace sys = boost::system;
+
+class user_category: public sys::error_category
+{
+public:
+
+    virtual const char * name() const BOOST_NOEXCEPT
+    {
+        return "user";
+    }
+
+    virtual std::string message( int ev ) const
+    {
+        char buffer[ 256 ];
+        std::sprintf( buffer, "user message %d", ev );
+
+        return buffer;
+    }
+
+    using sys::error_category::message;
+};
+
+static user_category s_cat_1;
+static user_category s_cat_2;
+
+int main()
+{
+    // default_error_condition
+
+    BOOST_TEST( s_cat_1.default_error_condition( 1 ).value() == 1 );
+    BOOST_TEST( s_cat_1.default_error_condition( 1 ).category() == s_cat_1 );
+
+    BOOST_TEST( s_cat_2.default_error_condition( 2 ).value() == 2 );
+    BOOST_TEST( s_cat_2.default_error_condition( 2 ).category() == s_cat_2 );
+
+    // equivalent
+
+    BOOST_TEST( s_cat_1.equivalent( 1, s_cat_1.default_error_condition( 1 ) ) );
+    BOOST_TEST( !s_cat_1.equivalent( 1, s_cat_1.default_error_condition( 2 ) ) );
+    BOOST_TEST( !s_cat_1.equivalent( 1, s_cat_2.default_error_condition( 2 ) ) );
+
+    // message
+
+    {
+        char buffer[ 256 ];
+        BOOST_TEST_CSTR_EQ( s_cat_1.message( 1, buffer, sizeof( buffer ) ), s_cat_1.message( 1 ).c_str() );
+    }
+
+    {
+        char buffer[ 4 ];
+        BOOST_TEST_CSTR_EQ( s_cat_1.message( 1, buffer, sizeof( buffer ) ), "use" );
+    }
+
+    // ==
+
+    BOOST_TEST_NOT( s_cat_1 == s_cat_2 );
+    BOOST_TEST( s_cat_1 != s_cat_2 );
+
+    return boost::report_errors();
+}

test/error_code_test.cpp

@@ -7,15 +7,12 @@
 
 //  See library home page at http://www.boost.org/libs/system
 
-//----------------------------------------------------------------------------// 
+//----------------------------------------------------------------------------//
 
 #include <boost/config/warning_disable.hpp>
 
-#include <boost/detail/lightweight_test.hpp>
 #include <boost/system/error_code.hpp>
-#include <boost/system/cygwin_error.hpp>
-#include <boost/system/linux_error.hpp>
-#include <boost/system/windows_error.hpp>
+#include <boost/core/lightweight_test.hpp>
 #include <iostream>
 #include <sstream>
 #include <string>
@@ -27,14 +24,20 @@
 //  with a boost::system using directive increases use scenario coverage.
 using namespace boost::system;
 
-# if defined( BOOST_WINDOWS_API )
-#   include "winerror.h"
-#   define BOOST_ACCESS_ERROR_MACRO ERROR_ACCESS_DENIED
-# elif defined( BOOST_POSIX_API )
-#   define BOOST_ACCESS_ERROR_MACRO EACCES
-# else
-#   error "Only supported for POSIX and Windows"
-# endif
+#if defined( BOOST_WINDOWS_API )
+// Neither MinGW or Cygwin versions of winerror.h work if used alone, so on
+// either of those platforms include the full windows.h
+#  if defined(__MINGW32__) || defined(__CYGWIN__)
+#    include <windows.h>
+#  else
+#    include <winerror.h>
+#  endif
+#  define BOOST_ACCESS_ERROR_MACRO ERROR_ACCESS_DENIED
+#elif defined( BOOST_POSIX_API )
+#  define BOOST_ACCESS_ERROR_MACRO EACCES
+#else
+#  error "Only supported for POSIX and Windows"
+#endif
 
 namespace
 {
@@ -47,6 +50,53 @@ namespace
     ss >> s;
     BOOST_TEST( s == expected );
   }
+
+  //  throws_function_test  ------------------------------------------------------------//
+
+  //  usage example
+
+  int divide(int dividend, int divisor, boost::system::error_code& ec = boost::throws())
+  {
+    if (divisor == 0)                            // is there an error?
+    {
+      if (&ec == &boost::throws())               // throw on error
+        throw "oops!";                           // whatever exception you prefer
+      ec = error_code(EDOM, generic_category()); // report error via error_code
+      return 0;
+    }
+    
+    if (&ec != &boost::throws())                 // error reporting via error_code
+      ec.clear();
+    return dividend / divisor;
+  }
+
+  //  test usage example
+
+  void test_throws_usage()
+  {
+    std::cout << "Test throws() example and usage...\n";
+    error_code ec;
+
+    // no error tests
+    BOOST_TEST_EQ((divide(10, 2)), 5);        // no error, report via exception
+    ec = make_error_code(errc::argument_out_of_domain);
+    BOOST_TEST_EQ((divide(10, 5, ec)), 2);    // no error, report via error_code
+    BOOST_TEST(!ec);
+
+    ec = make_error_code(errc::argument_out_of_domain);
+    BOOST_TEST_EQ((divide(10, 0, ec)), 0);    // error, report via error_code
+    BOOST_TEST(ec);
+
+    bool exception_thrown = false;            
+    try
+      { divide(10, 0); }                      // error, report via exception
+    catch (...)
+      { exception_thrown = true; }            
+    BOOST_TEST(exception_thrown);
+
+    //error_code should_fail(boost::throws());     // should fail at runtime
+    //boost::throws() = ec;                        // should fail at runtime
+  }
 }
 
 //  main  ------------------------------------------------------------------------------//
@@ -56,55 +106,52 @@ namespace
 int main( int, char ** )
 {
 
+  std::cout << "Conversion use cases...\n";
+  error_condition x1( errc::file_exists );
+  (void)x1;
+  //error_code x2( errc::file_exists ); // should fail to compile
+  make_error_code(errc::file_exists);
+  make_error_condition(errc::file_exists);
+
   std::cout << "General tests...\n";
   // unit tests:
 
-  BOOST_TEST( posix_category == posix_category );
-  BOOST_TEST( system_category == system_category );
-  BOOST_TEST( posix_category != system_category );
-  BOOST_TEST( system_category != posix_category );
-
-  if ( std::less<const error_category*>()( &posix_category, &system_category ) )
-  {
-    BOOST_TEST( posix_category < system_category );
-    BOOST_TEST( !(system_category < posix_category) );
-  }
-  else
-  {
-    BOOST_TEST( system_category < posix_category );
-    BOOST_TEST( !(posix_category < system_category) );
-  }
+  BOOST_TEST( generic_category() == generic_category() );
+  BOOST_TEST( system_category() == system_category() );
+  BOOST_TEST( generic_category() != system_category() );
+  BOOST_TEST( system_category() != generic_category() );
 
+  BOOST_TEST_NE( generic_category() < system_category(), system_category() < generic_category() );
 
   error_code ec;
-  error_condition dec;
+  error_condition econd;
   BOOST_TEST( !ec );
   BOOST_TEST( ec.value() == 0 );
-  dec = ec.default_error_condition();
-  BOOST_TEST( dec.value() == 0 );
-  BOOST_TEST( dec.category() == posix_category );
-  BOOST_TEST( ec == posix::success );
-  BOOST_TEST( ec.category() == system_category );
+  econd = ec.default_error_condition();
+  BOOST_TEST( econd.value() == 0 );
+  BOOST_TEST( econd.category() == generic_category() );
+  BOOST_TEST( ec == errc::success );
+  BOOST_TEST( ec.category() == system_category() );
   BOOST_TEST( std::strcmp( ec.category().name(), "system") == 0 );
-  BOOST_TEST( !(ec < error_code( 0, system_category )) );
-  BOOST_TEST( !(error_code( 0, system_category ) < ec) );
-  BOOST_TEST( ec < error_code( 1, system_category ) );
-  BOOST_TEST( !(error_code( 1, system_category ) < ec) );
+  BOOST_TEST( !(ec < error_code( 0, system_category() )) );
+  BOOST_TEST( !(error_code( 0, system_category() ) < ec) );
+  BOOST_TEST( ec < error_code( 1, system_category() ) );
+  BOOST_TEST( !(error_code( 1, system_category() ) < ec) );
 
-  error_code ec_0_system( 0, system_category );
+  error_code ec_0_system( 0, system_category() );
   BOOST_TEST( !ec_0_system );
   BOOST_TEST( ec_0_system.value() == 0 );
-  dec = ec_0_system.default_error_condition();
-  BOOST_TEST( dec.value() == 0 );
-  BOOST_TEST( dec.category() == posix_category );
-  BOOST_TEST( ec_0_system == posix::success );
-  BOOST_TEST( ec_0_system.category() == system_category );
+  econd = ec_0_system.default_error_condition();
+  BOOST_TEST( econd.value() == 0 );
+  BOOST_TEST( econd.category() == generic_category() );
+  BOOST_TEST( ec_0_system == errc::success );
+  BOOST_TEST( ec_0_system.category() == system_category() );
   BOOST_TEST( std::strcmp( ec_0_system.category().name(), "system") == 0 );
   check_ostream( ec_0_system, "system:0" );
 
   BOOST_TEST( ec_0_system == ec );
 
-  error_code ec_1_system( 1, system_category );
+  error_code ec_1_system( 1, system_category() );
   BOOST_TEST( ec_1_system );
   BOOST_TEST( ec_1_system.value() == 1 );
   BOOST_TEST( ec_1_system.value() != 0 );
@@ -112,41 +159,44 @@ int main( int, char ** )
   BOOST_TEST( ec_0_system != ec_1_system );
   check_ostream( ec_1_system, "system:1" );
 
-  ec = error_code( BOOST_ACCESS_ERROR_MACRO, system_category );
+  ec = error_code( BOOST_ACCESS_ERROR_MACRO, system_category() );
   BOOST_TEST( ec );
   BOOST_TEST( ec.value() == BOOST_ACCESS_ERROR_MACRO );
-  dec = ec.default_error_condition();
-  BOOST_TEST( dec.value() == static_cast<int>(posix::permission_denied) );
-  BOOST_TEST( dec.category() == posix_category );
-  BOOST_TEST( dec == error_condition( posix::permission_denied, posix_category ) );
-  BOOST_TEST( dec == posix::permission_denied );
-  BOOST_TEST( posix::permission_denied == dec );
-  BOOST_TEST( ec == posix::permission_denied );
-  BOOST_TEST( ec.category() == system_category );
+  econd = ec.default_error_condition();
+  BOOST_TEST( econd.value() == static_cast<int>(errc::permission_denied) );
+  BOOST_TEST( econd.category() == generic_category() );
+  BOOST_TEST( econd == error_condition( errc::permission_denied, generic_category() ) );
+  BOOST_TEST( econd == errc::permission_denied );
+  BOOST_TEST( errc::permission_denied == econd );
+  BOOST_TEST( ec == errc::permission_denied );
+  BOOST_TEST( ec.category() == system_category() );
   BOOST_TEST( std::strcmp( ec.category().name(), "system") == 0 );
 
-  // test the explicit make_error_code conversion for posix
-  ec = make_error_code( posix::bad_message );
+  // test the explicit make_error_code conversion for errc
+  ec = make_error_code( errc::bad_message );
   BOOST_TEST( ec );
-  BOOST_TEST( ec == posix::bad_message );
-  BOOST_TEST( posix::bad_message == ec );
-  BOOST_TEST( ec != posix::permission_denied );
-  BOOST_TEST( posix::permission_denied != ec );
-  BOOST_TEST( ec.category() == posix_category );
+  BOOST_TEST( ec == errc::bad_message );
+  BOOST_TEST( errc::bad_message == ec );
+  BOOST_TEST( ec != errc::permission_denied );
+  BOOST_TEST( errc::permission_denied != ec );
+  BOOST_TEST( ec.category() == generic_category() );
 
-  // test the deprecated predefined error_category synonyms
-  BOOST_TEST( &system_category == &native_ecat );
-  BOOST_TEST( &posix_category == &errno_ecat );
-  BOOST_TEST( system_category == native_ecat );
-  BOOST_TEST( posix_category == errno_ecat );
+  //// test the deprecated predefined error_category synonyms
+  //BOOST_TEST( &system_category() == &native_ecat );
+  //BOOST_TEST( &generic_category() == &errno_ecat );
+  //BOOST_TEST( system_category() == native_ecat );
+  //BOOST_TEST( generic_category() == errno_ecat );
 
   // test error_code and error_condition message();
   // see Boost.Filesystem operations_test for code specific message() tests
-  ec = error_code( -1, system_category );
+  ec = error_code( -1, system_category() );
   std::cout << "error_code message for -1 is \"" << ec.message() << "\"\n";
+  std::cout << "error_code message for 0 is \"" << ec_0_system.message() << "\"\n";
 #if defined(BOOST_WINDOWS_API)
   // Borland appends newline, so just check text
   BOOST_TEST( ec.message().substr(0,13) == "Unknown error" );
+  // Fails when the language isn't US English
+  // BOOST_TEST( ec_0_system.message().substr(0,36) == "The operation completed successfully" );
 #elif  defined(linux) || defined(__linux) || defined(__linux__)
   // Linux appends value to message as unsigned, so it varies with # of bits
   BOOST_TEST( ec.message().substr(0,13) == "Unknown error" );
@@ -158,108 +208,91 @@ int main( int, char ** )
   BOOST_TEST( ec.message() == "error -1" );
 #endif
 
-  ec = error_code( BOOST_ACCESS_ERROR_MACRO, system_category );
+  ec = error_code( BOOST_ACCESS_ERROR_MACRO, system_category() );
   BOOST_TEST( ec.message() != "" );
   BOOST_TEST( ec.message().substr( 0, 13) != "Unknown error" );
 
-  dec = error_condition( -1, posix_category );
-  std::cout << "error_condition message for -1 is \"" << dec.message() << "\"\n";
+  econd = error_condition( -1, generic_category() );
+  error_condition econd_ok;
+  std::cout << "error_condition message for -1 is \"" << econd.message() << "\"\n";
+  std::cout << "error_condition message for 0 is \"" << econd_ok.message() << "\"\n";
 #if defined(BOOST_WINDOWS_API)
   // Borland appends newline, so just check text
-  BOOST_TEST( dec.message().substr(0,13) == "Unknown error" );
+  BOOST_TEST( econd.message().substr(0,13) == "Unknown error" );
+  BOOST_TEST( econd_ok.message().substr(0,8) == "No error" );
 #elif  defined(linux) || defined(__linux) || defined(__linux__)
   // Linux appends value to message as unsigned, so it varies with # of bits
-  BOOST_TEST( dec.message().substr(0,13) == "Unknown error" );
+  BOOST_TEST( econd.message().substr(0,13) == "Unknown error" );
 #elif defined(__hpux)
-  BOOST_TEST( dec.message() == "" );
+  BOOST_TEST( econd.message() == "" );
 #elif defined(__osf__)
-  BOOST_TEST( dec.message() == "Error -1 occurred." );
+  BOOST_TEST( econd.message() == "Error -1 occurred." );
 #elif defined(__vms)
-  BOOST_TEST( dec.message() == "error -1" );
+  BOOST_TEST( econd.message() == "error -1" );
 #endif
 
-  dec = error_condition( BOOST_ACCESS_ERROR_MACRO, posix_category );
-  BOOST_TEST( dec.message() != "" );
-  BOOST_TEST( dec.message().substr( 0, 13) != "Unknown error" );
+  econd = error_condition( BOOST_ACCESS_ERROR_MACRO, generic_category() );
+  BOOST_TEST( econd.message() != "" );
+  BOOST_TEST( econd.message().substr( 0, 13) != "Unknown error" );
+
+  test_throws_usage();
 
 #ifdef BOOST_WINDOWS_API
   std::cout << "Windows tests...\n";
-  // these tests probe the Windows posix decoder
+  // these tests probe the Windows errc decoder
   //   test the first entry in the decoder table:
-  ec = error_code( ERROR_ACCESS_DENIED, system_category );
+  ec = error_code( ERROR_ACCESS_DENIED, system_category() );
   BOOST_TEST( ec.value() == ERROR_ACCESS_DENIED );
-  BOOST_TEST( ec == posix::permission_denied );
-  BOOST_TEST( ec.default_error_condition().value() == posix::permission_denied );
-  BOOST_TEST( ec.default_error_condition().category() == posix_category );
+  BOOST_TEST( ec == errc::permission_denied );
+  BOOST_TEST( ec.default_error_condition().value() == errc::permission_denied );
+  BOOST_TEST( ec.default_error_condition().category() == generic_category() );
 
   //   test the second entry in the decoder table:
-  ec = error_code( ERROR_ALREADY_EXISTS, system_category );
+  ec = error_code( ERROR_ALREADY_EXISTS, system_category() );
   BOOST_TEST( ec.value() == ERROR_ALREADY_EXISTS );
-  BOOST_TEST( ec == posix::file_exists );
-  BOOST_TEST( ec.default_error_condition().value() == posix::file_exists );
-  BOOST_TEST( ec.default_error_condition().category() == posix_category );
+  BOOST_TEST( ec == errc::file_exists );
+  BOOST_TEST( ec.default_error_condition().value() == errc::file_exists );
+  BOOST_TEST( ec.default_error_condition().category() == generic_category() );
 
   //   test the third entry in the decoder table:
-  ec = error_code( ERROR_BAD_UNIT, system_category );
+  ec = error_code( ERROR_BAD_UNIT, system_category() );
   BOOST_TEST( ec.value() == ERROR_BAD_UNIT );
-  BOOST_TEST( ec == posix::no_such_device );
-  BOOST_TEST( ec.default_error_condition().value() == posix::no_such_device );
-  BOOST_TEST( ec.default_error_condition().category() == posix_category );
+  BOOST_TEST( ec == errc::no_such_device );
+  BOOST_TEST( ec.default_error_condition().value() == errc::no_such_device );
+  BOOST_TEST( ec.default_error_condition().category() == generic_category() );
 
   //   test the last non-Winsock entry in the decoder table:
-  ec = error_code( ERROR_WRITE_PROTECT, system_category );
+  ec = error_code( ERROR_WRITE_PROTECT, system_category() );
   BOOST_TEST( ec.value() == ERROR_WRITE_PROTECT );
-  BOOST_TEST( ec == posix::permission_denied );
-  BOOST_TEST( ec.default_error_condition().value() == posix::permission_denied );
-  BOOST_TEST( ec.default_error_condition().category() == posix_category );
+  BOOST_TEST( ec == errc::permission_denied );
+  BOOST_TEST( ec.default_error_condition().value() == errc::permission_denied );
+  BOOST_TEST( ec.default_error_condition().category() == generic_category() );
 
   //   test the last Winsock entry in the decoder table:
-  ec = error_code( WSAEWOULDBLOCK, system_category );
+  ec = error_code( WSAEWOULDBLOCK, system_category() );
   BOOST_TEST( ec.value() == WSAEWOULDBLOCK );
-  BOOST_TEST( ec == posix::operation_would_block );
-  BOOST_TEST( ec.default_error_condition().value() == posix::operation_would_block );
-  BOOST_TEST( ec.default_error_condition().category() == posix_category );
+  BOOST_TEST( ec == errc::operation_would_block );
+  BOOST_TEST( ec.default_error_condition().value() == errc::operation_would_block );
+  BOOST_TEST( ec.default_error_condition().category() == generic_category() );
 
   //   test not-in-table condition:
-  ec = error_code( 1234567890, system_category );
+  ec = error_code( 1234567890, system_category() );
   BOOST_TEST( ec.value() == 1234567890 );
   BOOST_TEST( ec.default_error_condition().value() == 1234567890 );
-  BOOST_TEST( ec.default_error_condition().category() == system_category );
+  BOOST_TEST( ec.default_error_condition().category() == system_category() );
 
 #else // POSIX
 
   std::cout << "POSIX tests...\n";
-  ec = error_code( EACCES, system_category );
-  BOOST_TEST( ec == error_code( posix::permission_denied, system_category ) );
-  BOOST_TEST( error_code( posix::permission_denied, system_category ) == ec );
-  BOOST_TEST( ec == posix::permission_denied );
-  BOOST_TEST( posix::permission_denied == ec );
-  BOOST_TEST( ec.default_error_condition().value() == posix::permission_denied );
-  BOOST_TEST( ec.default_error_condition().category() == posix_category );
-
-# ifdef __CYGWIN__
-
-  std::cout << "Cygwin tests...\n";
-  ec = cygwin_error::no_package;
-  BOOST_TEST( ec == cygwin_error::no_package );
-  BOOST_TEST( ec == error_code( ENOPKG, system_category ) );
-  BOOST_TEST( ec == error_code( cygwin_error::no_package, system_category ) );
-  BOOST_TEST( ec.default_error_condition().category() == system_category );
-
-# elif defined(linux) || defined(__linux) || defined(__linux__)
-
-  std::cout << "Linux tests...\n";
-  ec = linux_error::dot_dot_error;
-  BOOST_TEST( ec == linux_error::dot_dot_error );
-  BOOST_TEST( ec == error_code( EDOTDOT, system_category ) );
-  BOOST_TEST( ec == error_code( linux_error::dot_dot_error, system_category ) );
-  BOOST_TEST( ec.default_error_condition().category() == system_category );
-
-# endif
+  ec = error_code( EACCES, system_category() );
+  BOOST_TEST( ec == error_code( errc::permission_denied, system_category() ) );
+  BOOST_TEST( error_code( errc::permission_denied, system_category() ) == ec );
+  BOOST_TEST( ec == errc::permission_denied );
+  BOOST_TEST( errc::permission_denied == ec );
+  BOOST_TEST( ec.default_error_condition().value() == errc::permission_denied );
+  BOOST_TEST( ec.default_error_condition().category() == generic_category() );
 
 #endif
   
   return ::boost::report_errors();
 }
-
-

test/error_code_test2.cpp

@@ -0,0 +1,94 @@
+// Copyright 2020, 2021 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/error_code.hpp>
+#include <boost/system/generic_category.hpp>
+#include <boost/system/system_category.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+namespace sys = boost::system;
+
+int main()
+{
+    char buffer[ 1024 ];
+
+    sys::error_code ec;
+
+    BOOST_TEST_EQ( ec.value(), 0 );
+    BOOST_TEST( ec.category() == sys::system_category() );
+    BOOST_TEST_EQ( ec.message(), ec.category().message( ec.value() ) );
+    BOOST_TEST_CSTR_EQ( ec.message( buffer, sizeof( buffer ) ), ec.category().message( ec.value(), buffer, sizeof( buffer ) ) );
+    BOOST_TEST( !ec.failed() );
+    BOOST_TEST( !ec );
+
+    BOOST_TEST_EQ( ec.to_string(), std::string( "system:0" ) );
+
+    {
+        sys::error_code ec2( ec );
+
+        BOOST_TEST_EQ( ec2.value(), 0 );
+        BOOST_TEST( ec2.category() == sys::system_category() );
+        BOOST_TEST_EQ( ec2.message(), ec2.category().message( ec2.value() ) );
+        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.category().message( ec2.value(), buffer, sizeof( buffer ) ) );
+        BOOST_TEST( !ec2.failed() );
+        BOOST_TEST( !ec2 );
+
+        BOOST_TEST_EQ( ec, ec2 );
+        BOOST_TEST_NOT( ec != ec2 );
+
+        BOOST_TEST_EQ( ec2.to_string(), std::string( "system:0" ) );
+    }
+
+    {
+        sys::error_code ec2( ec.value(), ec.category() );
+
+        BOOST_TEST_EQ( ec2.value(), 0 );
+        BOOST_TEST( ec2.category() == sys::system_category() );
+        BOOST_TEST_EQ( ec2.message(), ec2.category().message( ec2.value() ) );
+        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.category().message( ec2.value(), buffer, sizeof( buffer ) ) );
+        BOOST_TEST( !ec2.failed() );
+        BOOST_TEST( !ec2 );
+
+        BOOST_TEST_EQ( ec, ec2 );
+        BOOST_TEST_NOT( ec != ec2 );
+
+        BOOST_TEST_EQ( ec2.to_string(), std::string( "system:0" ) );
+    }
+
+    {
+        sys::error_code ec2( 5, sys::generic_category() );
+
+        BOOST_TEST_EQ( ec2.value(), 5 );
+        BOOST_TEST( ec2.category() == sys::generic_category() );
+        BOOST_TEST_EQ( ec2.message(), ec2.category().message( ec2.value() ) );
+        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.category().message( ec2.value(), buffer, sizeof( buffer ) ) );
+        BOOST_TEST( ec2.failed() );
+        BOOST_TEST( ec2 );
+        BOOST_TEST_NOT( !ec2 );
+
+        BOOST_TEST_NE( ec, ec2 );
+        BOOST_TEST_NOT( ec == ec2 );
+
+        BOOST_TEST_EQ( ec2.to_string(), std::string( "generic:5" ) );
+    }
+
+    {
+        sys::error_code ec2( 5, sys::system_category() );
+
+        BOOST_TEST_EQ( ec2.value(), 5 );
+        BOOST_TEST( ec2.category() == sys::system_category() );
+        BOOST_TEST_EQ( ec2.message(), ec2.category().message( ec2.value() ) );
+        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.category().message( ec2.value(), buffer, sizeof( buffer ) ) );
+        BOOST_TEST( ec2.failed() );
+        BOOST_TEST( ec2 );
+        BOOST_TEST_NOT( !ec2 );
+
+        BOOST_TEST_NE( ec, ec2 );
+        BOOST_TEST_NOT( ec == ec2 );
+
+        BOOST_TEST_EQ( ec2.to_string(), std::string( "system:5" ) );
+    }
+
+    return boost::report_errors();
+}

test/error_code_user_test.cpp

@@ -18,7 +18,7 @@
 #include <boost/cerrno.hpp>
 #include <string>
 #include <cstdio>
-#include <boost/test/minimal.hpp>
+#include <boost/detail/lightweight_test.hpp>
 
 #ifdef BOOST_POSIX_API
 # include <sys/stat.h>
@@ -40,7 +40,7 @@ boost::system::error_code my_mkdir( const std::string & path )
 #   else
       ::CreateDirectoryA( path.c_str(), 0 ) != 0 ? 0 : ::GetLastError(),
 #   endif
-      boost::system::system_category );
+      boost::system::system_category() );
 }
 
 //  ------------------------------------------------------------------------  //
@@ -53,9 +53,9 @@ boost::system::error_code my_remove( const std::string & path )
 {
   return boost::system::error_code(
     std::remove( path.c_str() ) == 0 ? 0 : errno,
-    boost::system::posix_category ); // OK for both Windows and POSIX
-                                     // Alternatively, could use posix_category
-                                     // on Windows and system_category on
+    boost::system::generic_category() ); // OK for both Windows and POSIX
+                                     // Alternatively, could use generic_category()
+                                     // on Windows and system_category() on
                                      // POSIX-based systems.
 }
 
@@ -73,7 +73,7 @@ namespace boost
   namespace lib3
   {
     // lib3 has its own error_category:
-    const boost::system::error_category & get_lib3_error_category();
+    const boost::system::error_category & get_lib3_error_category() BOOST_SYSTEM_NOEXCEPT;
     const boost::system::error_category & lib3_error_category = get_lib3_error_category();
     
     enum error
@@ -108,16 +108,18 @@ namespace boost
     class lib3_error_category_imp : public boost::system::error_category
     {
     public:
-      const char * name() const
+      lib3_error_category_imp() : boost::system::error_category() { }
+
+      const char * name() const BOOST_SYSTEM_NOEXCEPT
       {
         return "lib3";
       }
 
-      boost::system::error_condition default_error_condition( int ev ) const
+      boost::system::error_condition default_error_condition( int ev ) const BOOST_SYSTEM_NOEXCEPT
       {
         return ev == boo_boo
-          ? boost::system::error_condition( boost::system::posix::io_error,
-              boost::system::posix_category )
+          ? boost::system::error_condition( boost::system::errc::io_error,
+              boost::system::generic_category() )
           : boost::system::error_condition( ev,
               boost::lib3::lib3_error_category );
       }
@@ -131,7 +133,7 @@ namespace boost
 
     };
 
-    const boost::system::error_category & get_lib3_error_category()
+    const boost::system::error_category & get_lib3_error_category() BOOST_SYSTEM_NOEXCEPT
     {
       static const lib3_error_category_imp l3ecat;
       return l3ecat;
@@ -152,7 +154,7 @@ namespace boost
 namespace lib4
 {
   // lib4 has its own error_category:
-  const boost::system::error_category & get_lib4_error_category();
+  const boost::system::error_category & get_lib4_error_category() BOOST_SYSTEM_NOEXCEPT;
   const boost::system::error_category & lib4_error_category = get_lib4_error_category();
   
   extern const boost::system::error_code boo_boo;
@@ -168,16 +170,18 @@ namespace lib4
   class lib4_error_category_imp : public boost::system::error_category
   {
   public:
-    const char * name() const
+    lib4_error_category_imp() : boost::system::error_category() { }
+
+    const char * name() const BOOST_SYSTEM_NOEXCEPT
     {
       return "lib4";
     }
 
-    boost::system::error_condition default_error_condition( int ev ) const
+    boost::system::error_condition default_error_condition( int ev ) const  BOOST_SYSTEM_NOEXCEPT
     {
       return ev == boo_boo.value()
-        ? boost::system::error_condition( boost::system::posix::io_error,
-            boost::system::posix_category )
+        ? boost::system::error_condition( boost::system::errc::io_error,
+            boost::system::generic_category() )
         : boost::system::error_condition( ev, lib4::lib4_error_category );
     }
     
@@ -189,7 +193,7 @@ namespace lib4
     }
   };
 
-  const boost::system::error_category & get_lib4_error_category()
+  const boost::system::error_category & get_lib4_error_category() BOOST_SYSTEM_NOEXCEPT
   {
     static const lib4_error_category_imp l4ecat;
     return l4ecat;
@@ -233,15 +237,15 @@ namespace lib4
 //      switch (ev)
 //      {
 //        case user_success:
-//          return boost::system::error_code(boost::system::posix::success, boost::system::posix_category);
+//          return boost::system::error_code(boost::system::errc::success, boost::system::generic_category());
 //        case user_permission_denied:
-//          return boost::system::error_code(boost::system::posix::permission_denied, boost::system::posix_category);
+//          return boost::system::error_code(boost::system::errc::permission_denied, boost::system::generic_category());
 //        case user_out_of_memory:
-//          return boost::system::error_code(boost::system::posix::not_enough_memory, boost::system::posix_category);
+//          return boost::system::error_code(boost::system::errc::not_enough_memory, boost::system::generic_category());
 //        default:
 //          break;
 //      }
-//      return boost::system::error_code(boost::system::posix::no_posix_equivalent, boost::system::posix_category);
+//      return boost::system::error_code(boost::system::errc::no_posix_equivalent, boost::system::generic_category());
 //    }
 //    
 //  };
@@ -260,8 +264,8 @@ namespace lib4
 //
 //  void check_success(const boost::system::error_code& ec, bool expect)
 //  {
-//    BOOST_CHECK( (ec == boost::system::posix::success) == expect );
-//    if (ec == boost::system::posix::success)
+//    BOOST_TEST( (ec == boost::system::errc::success) == expect );
+//    if (ec == boost::system::errc::success)
 //      std::cout << "yes... " << (expect ? "ok" : "fail") << '\n';
 //    else
 //      std::cout << "no...  " << (expect ? "fail" : "ok") << '\n';
@@ -269,8 +273,8 @@ namespace lib4
 //
 //  void check_permission_denied(const boost::system::error_code& ec, bool expect)
 //  {
-//    BOOST_CHECK( (ec == boost::system::posix::permission_denied) == expect );
-//    if (ec ==  boost::system::posix::permission_denied)
+//    BOOST_TEST( (ec == boost::system::errc::permission_denied) == expect );
+//    if (ec ==  boost::system::errc::permission_denied)
 //      std::cout << "yes... " << (expect ? "ok" : "fail") << '\n';
 //    else
 //      std::cout << "no...  " << (expect ? "fail" : "ok") << '\n';
@@ -278,8 +282,8 @@ namespace lib4
 //
 //  void check_out_of_memory(const boost::system::error_code& ec, bool expect)
 //  {
-//    BOOST_CHECK( (ec == boost::system::posix::not_enough_memory) == expect );
-//    if (ec ==  boost::system::posix::not_enough_memory)
+//    BOOST_TEST( (ec == boost::system::errc::not_enough_memory) == expect );
+//    if (ec ==  boost::system::errc::not_enough_memory)
 //      std::cout << "yes... " << (expect ? "ok" : "fail") << '\n';
 //    else
 //      std::cout << "no...  " << (expect ? "fail" : "ok") << '\n';
@@ -291,23 +295,23 @@ namespace lib4
 //    printf("=====\n");
 //    boost::system::error_code ec;
 //    check_success(ec, true);
-//    check_success(boost::system::posix::success, true);
-//    check_success(boost::system::posix::permission_denied, false);
-//    check_success(boost::system::posix::not_enough_memory, false);
+//    check_success(boost::system::errc::success, true);
+//    check_success(boost::system::errc::permission_denied, false);
+//    check_success(boost::system::errc::not_enough_memory, false);
 //    check_success(user_success, true);
 //    check_success(user_permission_denied, false);
 //    check_success(user_out_of_memory, false);
 //    check_permission_denied(ec, false);
-//    check_permission_denied(boost::system::posix::success, false);
-//    check_permission_denied(boost::system::posix::permission_denied, true);
-//    check_permission_denied(boost::system::posix::not_enough_memory, false);
+//    check_permission_denied(boost::system::errc::success, false);
+//    check_permission_denied(boost::system::errc::permission_denied, true);
+//    check_permission_denied(boost::system::errc::not_enough_memory, false);
 //    check_permission_denied(user_success, false);
 //    check_permission_denied(user_permission_denied, true);
 //    check_permission_denied(user_out_of_memory, false);
 //    check_out_of_memory(ec, false);
-//    check_out_of_memory(boost::system::posix::success, false);
-//    check_out_of_memory(boost::system::posix::permission_denied, false);
-//    check_out_of_memory(boost::system::posix::not_enough_memory, true);
+//    check_out_of_memory(boost::system::errc::success, false);
+//    check_out_of_memory(boost::system::errc::permission_denied, false);
+//    check_out_of_memory(boost::system::errc::not_enough_memory, true);
 //    check_out_of_memory(user_success, false);
 //    check_out_of_memory(user_permission_denied, false);
 //    check_out_of_memory(user_out_of_memory, true);
@@ -333,7 +337,7 @@ namespace lib4
 
 //  ------------------------------------------------------------------------  //
 
-int test_main( int, char *[] )
+int main( int, char *[] )
 {
   boost::system::error_code ec;
 
@@ -342,35 +346,35 @@ int test_main( int, char *[] )
   ec = my_mkdir( "/no-such-file-or-directory/will-not-succeed" );
   std::cout << "ec.value() is " << ec.value() << '\n';
 
-  BOOST_CHECK( ec );
-  BOOST_CHECK( ec == boost::system::posix::no_such_file_or_directory );
-  BOOST_CHECK( ec.category() == boost::system::system_category );
+  BOOST_TEST( ec );
+  BOOST_TEST( ec == boost::system::errc::no_such_file_or_directory );
+  BOOST_TEST( ec.category() == boost::system::system_category() );
 
   // Library 2 tests:
 
   ec = my_remove( "/no-such-file-or-directory" );
   std::cout << "ec.value() is " << ec.value() << '\n';
 
-  BOOST_CHECK( ec );
-  BOOST_CHECK( ec == boost::system::posix::no_such_file_or_directory );
-  BOOST_CHECK( ec.category() == boost::system::posix_category );
+  BOOST_TEST( ec );
+  BOOST_TEST( ec == boost::system::errc::no_such_file_or_directory );
+  BOOST_TEST( ec.category() == boost::system::generic_category() );
 
   // Library 3 tests:
 
   ec = boost::lib3::boo_boo;
   std::cout << "ec.value() is " << ec.value() << '\n';
 
-  BOOST_CHECK( ec );
-  BOOST_CHECK( ec == boost::lib3::boo_boo );
-  BOOST_CHECK( ec.value() == boost::lib3::boo_boo );
-  BOOST_CHECK( ec.category() == boost::lib3::lib3_error_category );
+  BOOST_TEST( ec );
+  BOOST_TEST( ec == boost::lib3::boo_boo );
+  BOOST_TEST( ec.value() == boost::lib3::boo_boo );
+  BOOST_TEST( ec.category() == boost::lib3::lib3_error_category );
 
-  BOOST_CHECK( ec == boost::system::posix::io_error );
+  BOOST_TEST( ec == boost::system::errc::io_error );
 
   boost::system::error_code ec3( boost::lib3::boo_boo+100,
     boost::lib3::lib3_error_category );
-  BOOST_CHECK( ec3.category() == boost::lib3::lib3_error_category );
-  BOOST_CHECK( ec3.default_error_condition().category()
+  BOOST_TEST( ec3.category() == boost::lib3::lib3_error_category );
+  BOOST_TEST( ec3.default_error_condition().category()
     == boost::lib3::lib3_error_category );
 
   // Library 4 tests:
@@ -378,21 +382,21 @@ int test_main( int, char *[] )
   ec = lib4::boo_boo;
   std::cout << "ec.value() is " << ec.value() << '\n';
 
-  BOOST_CHECK( ec );
-  BOOST_CHECK( ec == lib4::boo_boo );
-  BOOST_CHECK( ec.value() == lib4::boo_boo.value() );
-  BOOST_CHECK( ec.category() == lib4::lib4_error_category );
+  BOOST_TEST( ec );
+  BOOST_TEST( ec == lib4::boo_boo );
+  BOOST_TEST( ec.value() == lib4::boo_boo.value() );
+  BOOST_TEST( ec.category() == lib4::lib4_error_category );
 
-  BOOST_CHECK( ec == boost::system::posix::io_error );
+  BOOST_TEST( ec == boost::system::errc::io_error );
 
   boost::system::error_code ec4( lib4::boo_boo.value()+100,
     lib4::lib4_error_category );
-  BOOST_CHECK( ec4.default_error_condition().category()
+  BOOST_TEST( ec4.default_error_condition().category()
     == lib4::lib4_error_category );
 
   // Test 3
 
   //test3::run();
 
-  return 0;
+  return ::boost::report_errors();
 }

test/error_condition_test.cpp

@@ -0,0 +1,31 @@
+// Copyright 2020 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/error_condition.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+namespace sys = boost::system;
+
+int main()
+{
+    sys::error_condition en;
+
+    BOOST_TEST_EQ( en.value(), 0 );
+    BOOST_TEST( !en );
+
+    sys::error_condition en2( en );
+
+    BOOST_TEST( en == en2 );
+    BOOST_TEST_NOT( en != en2 );
+
+    en2.assign( 1, en.category() );
+
+    BOOST_TEST_EQ( en2.value(), 1 );
+    BOOST_TEST( en2 );
+
+    BOOST_TEST_NOT( en == en2 );
+    BOOST_TEST( en != en2 );
+
+    return boost::report_errors();
+}

test/error_condition_test2.cpp

@@ -0,0 +1,25 @@
+// Copyright 2020 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/error_condition.hpp>
+#include <boost/system/errc.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+namespace sys = boost::system;
+
+int main()
+{
+    sys::error_condition en( sys::errc::no_such_file_or_directory );
+
+    BOOST_TEST_EQ( en.value(), ENOENT );
+
+    BOOST_TEST( en );
+    BOOST_TEST( !!en );
+
+    BOOST_TEST( en == make_error_condition( sys::errc::no_such_file_or_directory ) );
+
+    BOOST_TEST( en.category() == sys::error_condition().category() );
+
+    return boost::report_errors();
+}

test/error_condition_test3.cpp

@@ -0,0 +1,94 @@
+// Copyright 2020, 2021 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/error_condition.hpp>
+#include <boost/system/generic_category.hpp>
+#include <boost/system/system_category.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+namespace sys = boost::system;
+
+int main()
+{
+    char buffer[ 1024 ];
+
+    sys::error_condition en;
+
+    BOOST_TEST_EQ( en.value(), 0 );
+    BOOST_TEST( en.category() == sys::generic_category() );
+    BOOST_TEST_EQ( en.message(), en.category().message( en.value() ) );
+    BOOST_TEST_CSTR_EQ( en.message( buffer, sizeof( buffer ) ), en.category().message( en.value(), buffer, sizeof( buffer ) ) );
+    BOOST_TEST( !en.failed() );
+    BOOST_TEST( !en );
+
+    BOOST_TEST_EQ( en.to_string(), std::string( "cond:generic:0" ) );
+
+    {
+        sys::error_condition en2( en );
+
+        BOOST_TEST_EQ( en2.value(), 0 );
+        BOOST_TEST( en2.category() == sys::generic_category() );
+        BOOST_TEST_EQ( en2.message(), en2.category().message( en2.value() ) );
+        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.category().message( en2.value(), buffer, sizeof( buffer ) ) );
+        BOOST_TEST( !en2.failed() );
+        BOOST_TEST( !en2 );
+
+        BOOST_TEST_EQ( en, en2 );
+        BOOST_TEST_NOT( en != en2 );
+
+        BOOST_TEST_EQ( en2.to_string(), std::string( "cond:generic:0" ) );
+    }
+
+    {
+        sys::error_condition en2( en.value(), en.category() );
+
+        BOOST_TEST_EQ( en2.value(), 0 );
+        BOOST_TEST( en2.category() == sys::generic_category() );
+        BOOST_TEST_EQ( en2.message(), en2.category().message( en2.value() ) );
+        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.category().message( en2.value(), buffer, sizeof( buffer ) ) );
+        BOOST_TEST( !en2.failed() );
+        BOOST_TEST( !en2 );
+
+        BOOST_TEST_EQ( en, en2 );
+        BOOST_TEST_NOT( en != en2 );
+
+        BOOST_TEST_EQ( en2.to_string(), std::string( "cond:generic:0" ) );
+    }
+
+    {
+        sys::error_condition en2( 5, sys::generic_category() );
+
+        BOOST_TEST_EQ( en2.value(), 5 );
+        BOOST_TEST( en2.category() == sys::generic_category() );
+        BOOST_TEST_EQ( en2.message(), en2.category().message( en2.value() ) );
+        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.category().message( en2.value(), buffer, sizeof( buffer ) ) );
+        BOOST_TEST( en2.failed() );
+        BOOST_TEST( en2 );
+        BOOST_TEST_NOT( !en2 );
+
+        BOOST_TEST_NE( en, en2 );
+        BOOST_TEST_NOT( en == en2 );
+
+        BOOST_TEST_EQ( en2.to_string(), std::string( "cond:generic:5" ) );
+    }
+
+    {
+        sys::error_condition en2( 5, sys::system_category() );
+
+        BOOST_TEST_EQ( en2.value(), 5 );
+        BOOST_TEST( en2.category() == sys::system_category() );
+        BOOST_TEST_EQ( en2.message(), en2.category().message( en2.value() ) );
+        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.category().message( en2.value(), buffer, sizeof( buffer ) ) );
+        BOOST_TEST( en2.failed() );
+        BOOST_TEST( en2 );
+        BOOST_TEST_NOT( !en2 );
+
+        BOOST_TEST_NE( en, en2 );
+        BOOST_TEST_NOT( en == en2 );
+
+        BOOST_TEST_EQ( en2.to_string(), std::string( "cond:system:5" ) );
+    }
+
+    return boost::report_errors();
+}

test/failed_constexpr_test.cpp

@@ -0,0 +1,66 @@
+
+// Copyright 2018 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+
+#include <boost/system/error_code.hpp>
+#include <boost/config/pragma_message.hpp>
+#include <boost/static_assert.hpp>
+
+#if !defined(BOOST_SYSTEM_HAS_CONSTEXPR)
+
+BOOST_PRAGMA_MESSAGE("Skipping constexpr test, BOOST_SYSTEM_HAS_CONSTEXPR isn't defined")
+int main() {}
+
+#else
+
+using namespace boost::system;
+
+constexpr error_code ec1( 1, system_category() );
+
+BOOST_STATIC_ASSERT( ec1.failed() );
+BOOST_STATIC_ASSERT( ec1 );
+BOOST_STATIC_ASSERT( !!ec1 );
+
+constexpr error_code ec2( 2, generic_category() );
+
+BOOST_STATIC_ASSERT( ec2.failed() );
+BOOST_STATIC_ASSERT( ec2 );
+BOOST_STATIC_ASSERT( !!ec2 );
+
+constexpr error_code ec3;
+
+BOOST_STATIC_ASSERT( !ec3.failed() );
+BOOST_STATIC_ASSERT( ec3? false: true );
+BOOST_STATIC_ASSERT( !ec3 );
+
+#if defined(__GNUC__) && __GNUC__ == 7 && __cplusplus == 201703L
+
+// 'cat_' is not a constant expression
+
+#else
+
+constexpr error_condition en1( 1, system_category() );
+
+BOOST_STATIC_ASSERT( en1.failed() );
+BOOST_STATIC_ASSERT( en1 );
+BOOST_STATIC_ASSERT( !!en1 );
+
+constexpr error_condition en2( 2, generic_category() );
+
+BOOST_STATIC_ASSERT( en2.failed() );
+BOOST_STATIC_ASSERT( en2 );
+BOOST_STATIC_ASSERT( !!en2 );
+
+constexpr error_condition en3;
+
+BOOST_STATIC_ASSERT( !en3.failed() );
+BOOST_STATIC_ASSERT( en3? false: true );
+BOOST_STATIC_ASSERT( !en3 );
+
+#endif
+
+int main()
+{
+}
+
+#endif

test/failed_test.cpp

@@ -0,0 +1,185 @@
+
+// Copyright 2018 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+
+// Avoid spurious VC++ warnings
+#define _CRT_SECURE_NO_WARNINGS
+
+#include <boost/system/error_code.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cstdio>
+
+using namespace boost::system;
+
+struct http_category_impl: public error_category
+{
+    // clang++ 3.8 and below: initialization of const object
+    // requires a user-provided default constructor
+    BOOST_SYSTEM_CONSTEXPR http_category_impl() BOOST_NOEXCEPT
+    {
+    }
+
+    char const * name() const BOOST_NOEXCEPT
+    {
+        return "http";
+    }
+
+    std::string message( int ev ) const
+    {
+        char buffer[ 32 ];
+
+        std::sprintf( buffer, "HTTP/1.0 %d", ev );
+        return buffer;
+    }
+
+    bool failed( int ev ) const BOOST_NOEXCEPT
+    {
+        return !( ev >= 200 && ev < 300 );
+    }
+};
+
+error_category const & http_category()
+{
+    static const http_category_impl instance;
+    return instance;
+}
+
+#define TEST_NOT_FAILED(ec) BOOST_TEST( !ec.failed() ); BOOST_TEST( ec? false: true ); BOOST_TEST( !ec );
+#define TEST_FAILED(ec) BOOST_TEST( ec.failed() ); BOOST_TEST( ec ); BOOST_TEST( !!ec );
+
+template<class Ec> void test()
+{
+    {
+        Ec ec;
+        TEST_NOT_FAILED( ec );
+
+        ec.assign( 1, generic_category() );
+        TEST_FAILED( ec );
+
+        ec.clear();
+        TEST_NOT_FAILED( ec );
+
+        ec = Ec( 1, generic_category() );
+        TEST_FAILED( ec );
+
+        ec = Ec();
+        TEST_NOT_FAILED( ec );
+    }
+
+    {
+        Ec ec;
+        TEST_NOT_FAILED( ec );
+
+        ec.assign( 1, system_category() );
+        TEST_FAILED( ec );
+
+        ec.clear();
+        TEST_NOT_FAILED( ec );
+
+        ec = Ec( 1, system_category() );
+        TEST_FAILED( ec );
+
+        ec = Ec();
+        TEST_NOT_FAILED( ec );
+    }
+
+    {
+        Ec ec( 0, generic_category() );
+        TEST_NOT_FAILED( ec );
+
+        ec.assign( 1, system_category() );
+        TEST_FAILED( ec );
+
+        ec = Ec( 0, system_category() );
+        TEST_NOT_FAILED( ec );
+    }
+
+    {
+        Ec ec( 1, generic_category() );
+        TEST_FAILED( ec );
+
+        ec.assign( 0, system_category() );
+        TEST_NOT_FAILED( ec );
+    }
+
+    {
+        Ec ec( 0, system_category() );
+        TEST_NOT_FAILED( ec );
+
+        ec.assign( 1, generic_category() );
+        TEST_FAILED( ec );
+
+        ec = Ec( 0, generic_category() );
+        TEST_NOT_FAILED( ec );
+    }
+
+    {
+        Ec ec( 1, system_category() );
+        TEST_FAILED( ec );
+
+        ec.assign( 0, generic_category() );
+        TEST_NOT_FAILED( ec );
+    }
+
+    {
+        Ec ec( 0, http_category() );
+        TEST_FAILED( ec );
+
+        ec.assign( 200, http_category() );
+        TEST_NOT_FAILED( ec );
+
+        ec = Ec( 404, http_category() );
+        TEST_FAILED( ec );
+    }
+
+}
+
+int main()
+{
+    BOOST_TEST( !generic_category().failed( 0 ) );
+    BOOST_TEST( generic_category().failed( 7 ) );
+
+    BOOST_TEST( !system_category().failed( 0 ) );
+    BOOST_TEST( system_category().failed( 7 ) );
+
+    BOOST_TEST( http_category().failed( 0 ) );
+    BOOST_TEST( !http_category().failed( 200 ) );
+    BOOST_TEST( http_category().failed( 404 ) );
+
+    test<error_code>();
+    test<error_condition>();
+
+    {
+        error_condition ec( errc::success );
+        TEST_NOT_FAILED( ec );
+
+        ec = errc::address_family_not_supported;
+        TEST_FAILED( ec );
+    }
+
+    {
+        error_condition ec( errc::address_family_not_supported );
+        TEST_FAILED( ec );
+
+        ec = errc::success;
+        TEST_NOT_FAILED( ec );
+    }
+
+    {
+        error_code ec( make_error_code( errc::success ) );
+        TEST_NOT_FAILED( ec );
+
+        ec = make_error_code( errc::address_family_not_supported );
+        TEST_FAILED( ec );
+    }
+
+    {
+        error_code ec( make_error_code( errc::address_family_not_supported ) );
+        TEST_FAILED( ec );
+
+        ec = make_error_code( errc::success );
+        TEST_NOT_FAILED( ec );
+    }
+
+    return boost::report_errors();
+}

test/generic_category_test.cpp

@@ -0,0 +1,41 @@
+
+// Copyright 2018 Peter Dimov.
+//
+// Distributed under the Boost Software License, Version 1.0.
+//
+// See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt
+
+// See library home page at http://www.boost.org/libs/system
+
+// Avoid spurious VC++ warnings
+# define _CRT_SECURE_NO_WARNINGS
+
+#include <boost/system/error_code.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cstring>
+
+//
+
+namespace sys = boost::system;
+
+int main()
+{
+    sys::error_category const & cat = sys::generic_category();
+
+    // message
+
+    for( int i = -2; i < 1024; ++i )
+    {
+        {
+            BOOST_TEST_CSTR_EQ( cat.message( i ).c_str(), std::strerror( i ) );
+        }
+
+        {
+            char buffer[ 256 ];
+            BOOST_TEST_CSTR_EQ( cat.message( i, buffer, sizeof( buffer ) ), std::strerror( i ) );
+        }
+    }
+
+    return boost::report_errors();
+}

test/generic_category_test2.cpp

@@ -0,0 +1,20 @@
+// Copyright 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/generic_category.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+// Tests whether generic_category() is functional when only
+// generic_category.hpp is included
+
+namespace sys = boost::system;
+
+int main()
+{
+    sys::error_category const & cat = sys::generic_category();
+
+    BOOST_TEST_CSTR_EQ( cat.name(), "generic" );
+
+    return boost::report_errors();
+}

test/generic_category_test3.cpp

@@ -0,0 +1,30 @@
+// Copyright 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/generic_category.hpp>
+#include <boost/system/error_condition.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cerrno>
+
+namespace sys = boost::system;
+
+int main()
+{
+    sys::error_category const & cat = sys::generic_category();
+
+    // name
+    BOOST_TEST_CSTR_EQ( cat.name(), "generic" );
+
+    // default_error_condition
+    BOOST_TEST( cat.default_error_condition( 0 ) == sys::error_condition( 0, cat ) );
+    BOOST_TEST( cat.default_error_condition( ENOENT ) == sys::error_condition( ENOENT, cat ) );
+    BOOST_TEST( cat.default_error_condition( -1 ) == sys::error_condition( -1, cat ) );
+
+    // failed
+    BOOST_TEST( !cat.failed( 0 ) );
+    BOOST_TEST( cat.failed( ENOENT ) );
+    BOOST_TEST( cat.failed( -1 ) );
+
+    return boost::report_errors();
+}

test/header_only_test.cpp

@@ -1,4 +1,4 @@
-//  error_code_test.cpp  -----------------------------------------------------//
+//  header_only_test.cpp  -----------------------------------------------------//
 
 //  Copyright Beman Dawes 2007
 
@@ -13,12 +13,13 @@
 
 #define BOOST_ERROR_CODE_HEADER_ONLY
 
-#include <boost/test/minimal.hpp>
-
+#include <boost/detail/lightweight_test.hpp>
 #include <boost/system/error_code.hpp>
 
-int test_main( int, char*[] )
+int main()
 {
-  boost::system::error_code ec( 0, boost::system::system_category );
-  return 0;
+    boost::system::error_code ec( 0, boost::system::system_category() );
+    (void)ec;
+
+    return ::boost::report_errors();
 }