Split reference into headers

Update copyright
Document comparisons as inline friends; use value() and category() instead of val_ and cat_; add subheadings
2025-12-25 08:18:05 +01:00 · 2021-06-13 06:58:48 +03:00 · 2021-06-13 05:59:04 +03:00 · 2021-06-13 05:58:16 +03:00 · 2021-06-13 05:24:30 +03:00 · 2021-06-13 04:47:19 +03:00
61 changed files with 3540 additions and 2339 deletions
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,217 @@
+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-4.7
+            cxxstd: "03,11"
+            os: ubuntu-16.04
+            install: g++-4.7
+          - toolset: gcc-4.8
+            cxxstd: "03,11"
+            os: ubuntu-16.04
+            install: g++-4.8
+          - toolset: gcc-4.9
+            cxxstd: "03,11"
+            os: ubuntu-16.04
+            install: g++-4.9
+          - toolset: gcc-5
+            cxxstd: "03,11,14,1z"
+            os: ubuntu-16.04
+          - toolset: gcc-6
+            cxxstd: "03,11,14,1z"
+            os: ubuntu-16.04
+            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-18.04
+          - toolset: gcc-10
+            cxxstd: "03,11,14,17,2a"
+            os: ubuntu-18.04
+          - toolset: gcc-11
+            cxxstd: "03,11,14,17,2a"
+            os: ubuntu-18.04
+            install: g++-11
+          - toolset: clang
+            compiler: clang++-3.5
+            cxxstd: "03,11"
+            os: ubuntu-16.04
+            install: clang-3.5
+          - toolset: clang
+            compiler: clang++-3.6
+            cxxstd: "03,11,14"
+            os: ubuntu-16.04
+            install: clang-3.6
+          - toolset: clang
+            compiler: clang++-3.7
+            cxxstd: "03,11,14"
+            os: ubuntu-16.04
+            install: clang-3.7
+          - toolset: clang
+            compiler: clang++-3.8
+            cxxstd: "03,11,14"
+            os: ubuntu-16.04
+            install: clang-3.8
+          - toolset: clang
+            compiler: clang++-3.9
+            cxxstd: "03,11,14"
+            os: ubuntu-16.04
+            install: clang-3.9
+          - toolset: clang
+            compiler: clang++-4.0
+            cxxstd: "03,11,14"
+            os: ubuntu-16.04
+            install: clang-4.0
+          - toolset: clang
+            compiler: clang++-5.0
+            cxxstd: "03,11,14,1z"
+            os: ubuntu-16.04
+            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: "03,11,14,17,2a"
+            os: ubuntu-20.04
+          - 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-14.1
+            cxxstd: "14,17,latest"
+            addrmd: 32,64
+            os: windows-2016
+          - toolset: msvc-14.2
+            cxxstd: "14,17,latest"
+            addrmd: 32,64
+            os: windows-2019
+          - 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
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,8 +4,6 @@

 language: cpp

-sudo: false
-
 dist: xenial

 branches:
@@ -26,7 +24,26 @@ matrix:
  include:
    - os: linux
      compiler: g++
-      env: TOOLSET=gcc COMPILER=g++ CXXSTD=03,11
+      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
@@ -48,109 +65,16 @@ matrix:
          sources:
            - ubuntu-toolchain-r-test

-    - os: linux
-      compiler: g++-4.7
-      env: TOOLSET=gcc COMPILER=g++-4.7 CXXSTD=03,11
-      addons:
-        apt:
-          packages:
-            - g++-4.7
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      compiler: g++-4.8
-      env: TOOLSET=gcc COMPILER=g++-4.8 CXXSTD=03,11
-      addons:
-        apt:
-          packages:
-            - g++-4.8
-          sources:
-            - ubuntu-toolchain-r-test
-    - os: linux
-      compiler: g++-4.9
-      env: TOOLSET=gcc COMPILER=g++-4.9 CXXSTD=03,11
-      addons:
-        apt:
-          packages:
-            - g++-4.9
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      compiler: g++-5
-      env: TOOLSET=gcc COMPILER=g++-5 CXXSTD=03,11,14,1z
-      addons:
-        apt:
-          packages:
-            - g++-5
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      compiler: g++-6
-      env: TOOLSET=gcc COMPILER=g++-6 CXXSTD=03,11,14,1z
-      addons:
-        apt:
-          packages:
-            - g++-6
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      compiler: g++-7
-      env: TOOLSET=gcc COMPILER=g++-7 CXXSTD=03,11,14,17
-      addons:
-        apt:
-          packages:
-            - g++-7
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      compiler: g++-8
-      env: TOOLSET=gcc COMPILER=g++-8 CXXSTD=03,11,14,17,2a
-      addons:
-        apt:
-          packages:
-            - g++-8
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      compiler: g++-9
-      env: TOOLSET=gcc COMPILER=g++-9 CXXSTD=03,11,14,17,2a
-      addons:
-        apt:
-          packages:
-            - g++-9
-          sources:
-            - ubuntu-toolchain-r-test
-
    - os: linux
      dist: bionic
      compiler: g++-10
-      env: TOOLSET=gcc COMPILER=g++-10 CXXSTD=03,11,14,17,2a
+      env: UBSAN=1 TOOLSET=gcc COMPILER=g++-10 CXXSTD=03,11,14,17,20 UBSAN_OPTIONS=print_stacktrace=1 LINKFLAGS=-fuse-ld=gold
      addons:
        apt:
          packages:
            - g++-10
          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      compiler: g++-9
-      env: UBSAN=1 TOOLSET=gcc COMPILER=g++-9 CXXSTD=03,11,14,17,2a UBSAN_OPTIONS=print_stacktrace=1 LINKFLAGS=-fuse-ld=gold
-      addons:
-        apt:
-          packages:
-            - g++-9
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      compiler: clang++
-      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11
+            - sourceline: "ppa:ubuntu-toolchain-r/test"

    - os: linux
      dist: trusty
@@ -171,189 +95,75 @@ matrix:
            - clang-3.4

    - os: linux
-      dist: trusty
-      compiler: clang++-3.5
-      env: TOOLSET=clang COMPILER=clang++-3.5 CXXSTD=03,11,14,1z
+      compiler: clang++-11
+      env: UBSAN=1 TOOLSET=clang COMPILER=clang++-11 CXXSTD=03,11,14,17,20 UBSAN_OPTIONS=print_stacktrace=1
      addons:
        apt:
          packages:
-            - clang-3.5
+            - clang-11
          sources:
            - ubuntu-toolchain-r-test
-
-    - os: linux
-      compiler: clang++-3.6
-      env: TOOLSET=clang COMPILER=clang++-3.6 CXXSTD=03,11,14,1z
-      addons:
-        apt:
-          packages:
-            - clang-3.6
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      compiler: clang++-3.7
-      env: TOOLSET=clang COMPILER=clang++-3.7 CXXSTD=03,11,14,1z
-      addons:
-        apt:
-          packages:
-            - clang-3.7
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      compiler: clang++-3.8
-      env: TOOLSET=clang COMPILER=clang++-3.8 CXXSTD=03,11,14,1z
-      addons:
-        apt:
-          packages:
-            - clang-3.8
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      compiler: clang++-3.9
-      env: TOOLSET=clang COMPILER=clang++-3.9 CXXSTD=03,11,14,1z
-      addons:
-        apt:
-          packages:
-            - clang-3.9
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      compiler: clang++-4.0
-      env: TOOLSET=clang COMPILER=clang++-4.0 CXXSTD=03,11,14,1z
-      addons:
-        apt:
-          packages:
-            - clang-4.0
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      compiler: clang++-5.0
-      env: TOOLSET=clang COMPILER=clang++-5.0 CXXSTD=03,11,14,1z
-      addons:
-        apt:
-          packages:
-            - clang-5.0
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      compiler: clang++-6.0
-      env: TOOLSET=clang COMPILER=clang++-6.0 CXXSTD=03,11,14,17
-      addons:
-        apt:
-          packages:
-            - clang-6.0
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      compiler: clang++-7
-      env: TOOLSET=clang COMPILER=clang++-7 CXXSTD=03,11,14,17,2a
-      addons:
-        apt:
-          packages:
-            - clang-7
-          sources:
-            - ubuntu-toolchain-r-test
-            - llvm-toolchain-xenial-7
-
-    - os: linux
-      compiler: clang++-8
-      env: TOOLSET=clang COMPILER=clang++-8 CXXSTD=03,11,14,17,2a
-      addons:
-        apt:
-          packages:
-            - clang-8
-          sources:
-            - ubuntu-toolchain-r-test
-            - llvm-toolchain-xenial-8
-
-    - os: linux
-      compiler: clang++-9
-      env: TOOLSET=clang COMPILER=clang++-9 CXXSTD=03,11,14,17,2a
-      addons:
-        apt:
-          packages:
-            - clang-9
-          sources:
-            - ubuntu-toolchain-r-test
-            - sourceline: 'deb https://apt.llvm.org/xenial/ llvm-toolchain-xenial-9 main'
+            - sourceline: 'deb https://apt.llvm.org/xenial/ llvm-toolchain-xenial-11 main'
              key_url: 'https://apt.llvm.org/llvm-snapshot.gpg.key'

    - os: linux
-      dist: xenial
-      compiler: clang++-10
-      env: TOOLSET=clang COMPILER=clang++-10 CXXSTD=03,11,14,17,2a
-      addons:
-        apt:
-          packages:
-            - clang-10
-          sources:
-            - ubuntu-toolchain-r-test
-            - sourceline: 'deb https://apt.llvm.org/xenial/ llvm-toolchain-xenial-10 main'
-              key_url: 'https://apt.llvm.org/llvm-snapshot.gpg.key'
-
-    - os: linux
-      dist: xenial
-      compiler: clang++-10
-      env: UBSAN=1 TOOLSET=clang COMPILER=clang++-10 CXXSTD=03,11,14,17,2a UBSAN_OPTIONS=print_stacktrace=1
-      addons:
-        apt:
-          packages:
-            - clang-10
-          sources:
-            - ubuntu-toolchain-r-test
-            - sourceline: 'deb https://apt.llvm.org/xenial/ llvm-toolchain-xenial-10 main'
-              key_url: 'https://apt.llvm.org/llvm-snapshot.gpg.key'
-
-    - os: linux
-      dist: trusty
+      dist: bionic
      compiler: clang++-libc++
-      env: TOOLSET=clang COMPILER=clang++-libc++ CXXSTD=03,11,14,1z
+      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: linux
-      dist: trusty
-      compiler: clang++-libc++
-      env: UBSAN=1 TOOLSET=clang COMPILER=clang++-libc++ CXXSTD=03,11,14,1z UBSAN_OPTIONS=print_stacktrace=1
-      addons:
-        apt:
-          packages:
-            - libc++-dev
-
-    - os: osx
-      compiler: clang++
-      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z
-
-    - os: osx
-      compiler: clang++
-      env: UBSAN=1 TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z UBSAN_OPTIONS=print_stacktrace=1
-
    - 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_ENABLE_CMAKE=1 -DBoost_VERBOSE=1 -DBOOST_INCLUDE_LIBRARIES=system -DBUILD_TESTING=ON ..
-        - ctest --output-on-failure -R boost_system
+        - 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 -DBOOST_ENABLE_CMAKE=1 -DBoost_VERBOSE=1 -DBUILD_SHARED_LIBS=ON -DBOOST_INCLUDE_LIBRARIES=system -DBUILD_TESTING=ON ..
-        - ctest --output-on-failure -R boost_system
+        - 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
@@ -375,7 +185,7 @@ matrix:
      script:
        - pip install --user cmake
        - mkdir __build__ && cd __build__
-        - cmake -DBOOST_ENABLE_CMAKE=1 -DBoost_VERBOSE=1 -DBOOST_INCLUDE_LIBRARIES="system;core" -DBUILD_TESTING=OFF -DCMAKE_INSTALL_PREFIX=~/.local ..
+        - 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 ..
@@ -396,7 +206,7 @@ install:
 script:
  - |-
    echo "using $TOOLSET : : $COMPILER ;" > ~/user-config.jam
-  - ./b2 -j3 libs/system/test toolset=$TOOLSET cxxstd=$CXXSTD variant=debug,release ${UBSAN:+cxxflags=-fsanitize=undefined cxxflags=-fno-sanitize-recover=undefined linkflags=-fsanitize=undefined define=UBSAN=1 debug-symbols=on} ${LINKFLAGS:+linkflags=$LINKFLAGS}
+  - ./b2 -j3 libs/system/test toolset=$TOOLSET cxxstd=$CXXSTD variant=debug,release ${ADDRMD:+address-model=$ADDRMD} ${UBSAN:+undefined-sanitizer=norecover define=UBSAN=1 debug-symbols=on} ${LINKFLAGS:+linkflags=$LINKFLAGS}

 notifications:
  email:
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -16,6 +16,7 @@ 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
--- a/doc/system.adoc
+++ b/doc/system.adoc
@@ -10,7 +10,7 @@ http://www.boost.org/LICENSE_1_0.txt
 # Boost.System: Extensible Error Reporting
 Beman Dawes, Christopher Kohlhoff, Peter Dimov
 :toc: left
-:toclevels: 3
+:toclevels: 4
 :idprefix:
 :docinfo: private-footer

--- a/doc/system/changes.adoc
+++ b/doc/system/changes.adoc
@@ -1,5 +1,5 @@
 ////
-Copyright 2018 Peter Dimov
+Copyright 2018-2021 Peter Dimov

 Distributed under the Boost Software License, Version 1.0.

@@ -11,6 +11,44 @@ http://www.boost.org/LICENSE_1_0.txt
 # Revision History
 :idprefix:

+## 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.
+
+## 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`.
--- a/doc/system/copyright.adoc
+++ b/doc/system/copyright.adoc
@@ -1,5 +1,5 @@
 ////
-Copyright 2018 Peter Dimov
+Copyright 2018-2021 Peter Dimov

 Distributed under the Boost Software License, Version 1.0.

@@ -14,6 +14,6 @@ http://www.boost.org/LICENSE_1_0.txt
 This documentation is

 * Copyright 2003-2017 Beman Dawes
-* Copyright 2018 Peter Dimov
+* Copyright 2018-2021 Peter Dimov

 and is distributed under the http://www.boost.org/LICENSE_1_0.txt[Boost Software License, Version 1.0].
--- a/doc/system/reference.adoc
+++ b/doc/system/reference.adoc
@@ -1,6 +1,6 @@
 ////
 Copyright 2003-2017 Beman Dawes
-Copyright 2018 Peter Dimov
+Copyright 2018-2021 Peter Dimov

 Distributed under the Boost Software License, Version 1.0.

@@ -48,31 +48,53 @@ the old names, but will provide them when the macro `BOOST_SYSTEM_ENABLE_DEPRECA
 |`native_ecat`|`system_category()`
 |===

-## <boost/system/error_code.hpp>
+## <boost/system/{zwsp}is_error_code_enum.hpp>

-### Synopsis
+### is_error_code_enum

 ```
 namespace boost {
  namespace system {

-    class error_category;
-
-    constexpr const error_category & system_category() noexcept;
-    constexpr const error_category & generic_category() noexcept;
-
-    class error_code;
-    class error_condition;
-
-    // "Concept" helpers
-
    template<class T>
      struct is_error_code_enum { static const bool value = false; };

+  } // namespace system
+} // namespace boost
+```
+
+Users may specialize `is_error_code_enum` for their error enumeration
+types to indicate that they should be eligible for automatic conversions
+to `error_code`. This conversion calls `make_error_code(e)`, which should
+be provided in the same namespace as the enumeration type.
+
+## <boost/system/{zwsp}is_error_condition_enum.hpp>
+
+### is_error_condition_enum
+
+```
+namespace boost {
+  namespace system {
+
    template<class T>
      struct is_error_condition_enum { static const bool value = false; };

-    // generic error conditions
+  } // namespace system
+} // namespace boost
+```
+
+Users may specialize `is_error_condition_enum` for their error enumeration
+types to indicate that they should be eligible for automatic conversions
+to `error_condition`. This conversion calls `make_error_condition(e)`, which
+should be provided in the same namespace as the enumeration type.
+
+## <boost/system/{zwsp}errc.hpp>
+
+### errc
+
+```
+namespace boost {
+  namespace system {

    namespace errc {
      enum errc_t
@@ -163,52 +185,80 @@ namespace boost {
    template<> struct is_error_condition_enum<errc::errc_t>
      { static const bool value = true; };

-    // non-member functions
-
-    constexpr bool operator==( const error_code & lhs,
-      const error_code & rhs ) noexcept;
-    bool operator==( const error_code & code,
-      const error_condition & condition ) noexcept;
-    bool operator==( const error_condition & condition,
-      const error_code & code ) noexcept;
-    constexpr bool operator==( const error_condition & lhs,
-      const error_condition & rhs ) noexcept;
-
-    constexpr bool operator!=( const error_code & lhs,
-      const error_code & rhs ) noexcept;
-    bool operator!=( const error_code & code,
-      const error_condition & condition ) noexcept;
-    bool operator!=( const error_condition & condition,
-      const error_code & code ) noexcept;
-    constexpr bool operator!=( const error_condition & lhs,
-      const error_condition & rhs ) noexcept;
-
-    constexpr bool operator<( const error_code & lhs,
-      const error_code & rhs ) noexcept;
-    constexpr bool operator<( const error_condition & lhs,
-      const error_condition & rhs ) noexcept;
-
    constexpr error_code make_error_code( errc::errc_t e ) noexcept;
    constexpr error_condition make_error_condition( errc::errc_t e ) noexcept;

-    template <class charT, class traits>
-      std::basic_ostream<charT, traits>&
-        operator<<( basic_ostream<charT, traits>& os, const error_code & ec );
-
-    std::size_t hash_value( const error_code & ec );
-
  } // namespace system
 } // namespace boost
 ```

-The value of each `errc_t` constant is the same as the value of the `<cerrno>`
-macro shown in the above synopsis.
+The predefined enumeration type `errc::errc_t` provides named constants
+corresponding to the values of the `<cerrno>` macros.

-Users may specialize `is_error_code_enum` and `is_error_condition_enum`
-templates to indicate that a type is eligible for class `error_code` and
-`error_condition` automatic conversions respectively.
+```
+constexpr error_condition make_error_condition( errc::errc_t e ) noexcept;
+```
+[none]
+* {blank}
+
+Returns: :: `error_condition( e, generic_category() )`.

-### Class error_category
+Since `errc::errc_t` provides a specialization of `is_error_condition_enum`
+and an overload of `make_error_condition`, it can be converted implicitly to
+an `error_condition`. This is typically useful when comparing `error_code`
+values returned from APIs to a portable condition, as in the below example:
+* {blank}
+
+```
+void api_function( boost::system::error_code& ec );
+
+void my_function()
+{
+    boost::system::error_code ec;
+    api_function( ec );
+
+    if( ec == boost::system::errc::no_such_file_or_directory )
+    {
+        // an entity wasn't found (ENOENT)
+        // handle this condition
+    }
+}
+```
+
+```
+constexpr error_code make_error_code( errc::errc_t e ) noexcept;
+```
+[none]
+* {blank}
+
+Returns: :: `error_code( e, generic_category() )`.
+
+In addition to `make_error_condition`, `errc::errc_t` provides an overload of
+`make_error_code`. This allows the creation of generic error codes, an
+operation typically useful when a function needs to signal a generic failure
+that does not come from an underlying API, such as for instance an out of
+memory condition:
+* {blank}
+
+```
+void my_api_function( boost::system::error_code& ec )
+{
+    void* p = std::malloc( 16 );
+
+    if( p == 0 )
+    {
+        // return ENOMEM
+        ec = make_error_code( boost::system::errc::out_of_memory );
+        return;
+    }
+
+    // use p
+}
+```
+
+## <boost/system/{zwsp}error_category.hpp>
+
+### error_category

 The class `error_category` defines the base class for types used
 to identify the source and encoding of a particular category of error code.
@@ -251,9 +301,13 @@ namespace boost {

      virtual bool failed( int ev ) const noexcept;

-      constexpr bool operator==( const error_category & rhs ) const noexcept;
-      constexpr bool operator!=( const error_category & rhs ) const noexcept;
-      constexpr bool operator< ( const error_category & rhs ) const noexcept;
+      friend constexpr bool operator==( const error_category & lhs,
+        const error_category & rhs ) noexcept;
+      friend constexpr bool operator!=( const error_category & lhs,
+        const error_category & rhs ) noexcept;
+
+      friend constexpr bool operator< ( const error_category & lhs,
+        const error_category & rhs ) noexcept;

      operator std::error_category const & () const;

@@ -397,37 +451,42 @@ Returns: ::
 Remarks: ::
  All calls to this function with the same `ev` must return the same value.

-#### Nonvirtuals
+#### Comparisons

 ```
-constexpr bool operator==( const error_category & rhs ) const noexcept;
+friend constexpr bool operator==( const error_category & lhs,
+  const error_category & rhs ) noexcept;
 ```
 [none]
 * {blank}
 +
-Returns: :: `rhs.id_ == 0? this == &rhs: id_ == rhs.id_`.
-Remarks: :: Two category objects are considered equivalent when they have matching
-  nonzero identifiers, or are the same object.
+Returns: :: `rhs.id_ == 0? &lhs == &rhs: lhs.id_ == rhs.id_`.
+Remarks: :: Two category objects are considered equivalent when they have
+  matching nonzero identifiers, or are the same object.

 ```
-constexpr bool operator!=( const error_category & rhs ) const noexcept;
+friend constexpr bool operator!=( const error_category & lhs,
+  const error_category & rhs ) noexcept;
 ```
 [none]
 * {blank}
 +
-Returns: :: `!( *this == rhs )`.
+Returns: :: `!( lhs == rhs )`.

 ```
-constexpr bool operator< ( const error_category & rhs ) const noexcept;
+constexpr bool operator< ( const error_category & lhs,
+  const error_category & rhs ) const noexcept;
 ```
 [none]
 * {blank}
 +
 Returns: ::
-** If `id_ < rhs.id_`, `true`;
-** Otherwise, if `id_ > rhs.id_`, `false`;
+** If `lhs.id_ < rhs.id_`, `true`;
+** Otherwise, if `lhs.id_ > rhs.id_`, `false`;
 ** Otherwise, if `rhs.id_ != 0`, `false`;
-** Otherwise, `std::less<error_category const *>()( this, &rhs )`.
+** Otherwise, `std::less<error_category const *>()( &lhs, &rhs )`.
+
+#### Conversions

 ```
 operator std::error_category const & () const;
@@ -438,7 +497,19 @@ operator std::error_category const & () const;
 Returns: :: A reference to an `std::error_category` object corresponding
  to `*this`.

-### Predefined Categories
+## <boost/system/{zwsp}system_category.hpp>
+
+### system_category
+
+```
+namespace boost {
+  namespace system {
+
+    constexpr const error_category & system_category() noexcept;
+
+  } // namespace system
+} // namespace boost
+```

 ```
 constexpr const error_category & system_category() noexcept;
@@ -446,8 +517,22 @@ constexpr const error_category & system_category() noexcept;
 [none]
 * {blank}
 +
-Returns: :: A reference to an `error_category` object identifying errors
-  originating from the operating system.
+Returns: :: A reference to a predefined `error_category` object identifying
+  errors originating from the operating system.
+
+## <boost/system/{zwsp}generic_category.hpp>
+
+### generic_category
+
+```
+namespace boost {
+  namespace system {
+
+    constexpr const error_category & generic_category() noexcept;
+
+  } // namespace system
+} // namespace boost
+```

 ```
 constexpr const error_category & generic_category() noexcept;
@@ -455,10 +540,12 @@ constexpr const error_category & generic_category() noexcept;
 [none]
 * {blank}
 +
-Returns: :: A reference to an `error_category` object identifying portable
-  error conditions.
+Returns: :: A reference to a predefined `error_category` object identifying
+  portable error codes and conditions.

-### Class error_code
+## <boost/system/{zwsp}error_code.hpp>
+
+### error_code

 The class `error_code` describes an object used to hold error code
 values, such as those originating from the operating system or other
@@ -502,14 +589,39 @@ namespace boost {
      constexpr bool failed() const noexcept;
      constexpr explicit operator bool() const noexcept;

+      // comparisons:
+
+      friend constexpr bool operator==( const error_code & lhs,
+        const error_code & rhs ) noexcept;
+      friend constexpr bool operator!=( const error_code & lhs,
+        const error_code & rhs ) noexcept;
+
+      friend constexpr bool operator<( const error_code & lhs,
+        const error_code & rhs ) noexcept;
+
+      // conversions:
+
      operator std::error_code() const;
-
-    private: // exposition only
-
-      int val_;
-      const error_category * cat_;
-
    };
+
+    // non-member functions
+
+    bool operator==( const error_code & code,
+      const error_condition & condition ) noexcept;
+    bool operator==( const error_condition & condition,
+      const error_code & code ) noexcept;
+
+    bool operator!=( const error_code & code,
+      const error_condition & condition ) noexcept;
+    bool operator!=( const error_condition & condition,
+      const error_code & code ) noexcept;
+
+    template <class charT, class traits>
+      std::basic_ostream<charT, traits>&
+        operator<<( basic_ostream<charT, traits>& os, const error_code & ec );
+
+    std::size_t hash_value( const error_code & ec );
+
  }
 }
 ```
@@ -522,7 +634,7 @@ constexpr error_code() noexcept;
 [none]
 * {blank}
 +
-Ensures: :: `val_ == 0`; `*cat_ == system_category()`.
+Ensures: :: `value() == 0`; `category() == system_category()`.

 ```
 constexpr error_code( int val, const error_category & cat ) noexcept;
@@ -530,7 +642,7 @@ constexpr error_code( int val, const error_category & cat ) noexcept;
 [none]
 * {blank}
 +
-Ensures: :: `val_ == val`; `cat_ == &cat`.
+Ensures: :: `value() == val`; `category() == cat`.

 ```
 template <class ErrorCodeEnum>
@@ -550,7 +662,7 @@ constexpr void assign( int val, const error_category & cat ) noexcept;
 [none]
 * {blank}
 +
-Ensures: :: `val_ == val`; `cat_ == &cat`.
+Ensures: :: `value() == val`; `category() == cat`.

 ```
 template<typename ErrorCodeEnum>
@@ -569,7 +681,7 @@ constexpr void clear() noexcept;
 * {blank}
 +
 Ensures: ::
-  `val_ == 0`; `*cat_ == system_category()`.
+  `value() == 0`; `category() == system_category()`.

 #### Observers

@@ -579,7 +691,7 @@ constexpr int value() const noexcept;
 [none]
 * {blank}
 +
-Returns: :: `val_`.
+Returns: :: the error value.

 ```
 constexpr const error_category & category() const noexcept;
@@ -587,7 +699,7 @@ constexpr const error_category & category() const noexcept;
 [none]
 * {blank}
 +
-Returns: :: `*cat_`.
+Returns: :: the error category.

 ```
 error_condition default_error_condition() const noexcept;
@@ -595,7 +707,7 @@ error_condition default_error_condition() const noexcept;
 [none]
 * {blank}
 +
-Returns: :: `cat_\->default_error_condition( val_ )`.
+Returns: :: `category().default_error_condition( value() )`.

 ```
 std::string message() const;
@@ -603,7 +715,7 @@ std::string message() const;
 [none]
 * {blank}
 +
-Returns: :: `cat_\->message( val_ )`.
+Returns: :: `category().message( value() )`.

 ```
 char const * message( char * buffer, std::size_t len ) const noexcept;
@@ -611,7 +723,7 @@ char const * message( char * buffer, std::size_t len ) const noexcept;
 [none]
 * {blank}
 +
-Returns: :: `cat_\->message( val_, buffer, len )`.
+Returns: :: `category().message( value(), buffer, len )`.

 ```
 constexpr bool failed() const noexcept;
@@ -619,7 +731,7 @@ constexpr bool failed() const noexcept;
 [none]
 * {blank}
 +
-Returns: :: `cat_\->failed( val_ )`.
+Returns: :: `category().failed( value() )`.

 ```
 constexpr explicit operator bool() const noexcept;
@@ -627,7 +739,40 @@ constexpr explicit operator bool() const noexcept;
 [none]
 * {blank}
 +
-Returns: :: `failed()`.
+Returns: ::
+  `failed()`.
+
+#### Comparisons
+
+```
+friend constexpr bool operator==( const error_code & lhs,
+  const error_code & rhs ) noexcept;
+```
+[none]
+* {blank}
+
+Returns: :: `lhs.value() == rhs.value() && lhs.category() == rhs.category()`.
+
+```
+friend constexpr bool operator!=( const error_code & lhs,
+  const error_code & rhs ) noexcept;
+```
+[none]
+* {blank}
+
+Returns: :: `!( lhs == rhs )`.
+
+```
+friend constexpr bool operator<( const error_code & lhs,
+  const error_code & rhs ) noexcept;
+```
+[none]
+* {blank}
+
+Returns: ::
+  `lhs.category() < rhs.category() || (lhs.category() == rhs.category() && lhs.value() < rhs.value())`.
+
+#### Conversions

 ```
 operator std::error_code() const;
@@ -636,9 +781,55 @@ operator std::error_code() const;
 * {blank}
 +
 Returns: ::
-  `std::error_code( val_, *cat_ )`.
+  `std::error_code( value(), category() )`.

-### Class error_condition
+#### Nonmembers
+
+```
+bool operator==( const error_code & code,
+  const error_condition & condition ) noexcept;
+bool operator==( const error_condition & condition,
+  const error_code & code ) noexcept;
+```
+[none]
+* {blank}
+
+Returns: :: `code.category().equivalent(code.value(), condition) || condition.category().equivalent(code, condition.value())`.
+
+```
+bool operator!=( const error_code & code,
+  const error_condition & condition ) noexcept;
+bool operator!=( const error_condition & condition,
+  const error_code & code ) noexcept;
+```
+[none]
+* {blank}
+
+Returns: :: `!( lhs == rhs )`.
+
+```
+template <class charT, class traits>
+  std::basic_ostream<charT, traits>&
+    operator<<( basic_ostream<charT, traits>& os, const error_code & ec );
+```
+[none]
+* {blank}
+
+Effects: :: `os << ec.category().name() << ':' << ec.value()`.
+Returns: :: `os`.
+
+```
+std::size_t hash_value( const error_code & ec );
+```
+[none]
+* {blank}
+
+Returns: ::
+  A hash value representing `ec`.
+
+## <boost/system/{zwsp}error_condition.hpp>
+
+### error_condition

 ```
 namespace boost {
@@ -675,13 +866,19 @@ namespace boost {
      constexpr bool failed() const noexcept;
      constexpr explicit operator bool() const noexcept;

+      // comparisons:
+
+      friend constexpr bool operator==( const error_condition & lhs,
+        const error_condition & rhs ) noexcept;
+      friend constexpr bool operator!=( const error_condition & lhs,
+        const error_condition & rhs ) noexcept;
+
+      friend constexpr bool operator<( const error_condition & lhs,
+        const error_condition & rhs ) noexcept;
+
+      // conversions:
+
      operator std::error_condition() const;
-
-    private: // exposition only
-
-      int val_;
-      const error_category * cat_;
-
    };
  }
 }
@@ -695,7 +892,7 @@ constexpr error_condition() noexcept;
 [none]
 * {blank}
 +
-Ensures: :: `val_ == 0`; `*cat_ == generic_category()`.
+Ensures: :: `value() == 0`; `category() == generic_category()`.

 ```
 constexpr error_condition( int val, const error_category & cat ) noexcept;
@@ -703,7 +900,7 @@ constexpr error_condition( int val, const error_category & cat ) noexcept;
 [none]
 * {blank}
 +
-Ensures: :: `val_ == val`; `cat_ == &cat`.
+Ensures: :: `value() == val`; `category() == cat`.

 ```
 template <class ErrorConditionEnum>
@@ -724,7 +921,7 @@ constexpr void assign( int val, const error_category & cat ) noexcept;
 [none]
 * {blank}
 +
-Ensures: :: `val_ == val`; `cat_ == &cat`.
+Ensures: :: `value() == val`; `category() == cat`.

 ```
 template <class ErrorConditionEnum>
@@ -743,7 +940,7 @@ constexpr void clear() noexcept;
 * {blank}
 +
 Ensures: ::
-  `val_ == 0`; `*cat_ == generic_category()`.
+  `value() == 0`; `category() == generic_category()`.

 #### Observers

@@ -753,7 +950,7 @@ constexpr int value() const noexcept;
 [none]
 * {blank}
 +
-Returns: :: `val_`.
+Returns: :: the error value.

 ```
 constexpr const error_category & category() const noexcept;
@@ -761,7 +958,7 @@ constexpr const error_category & category() const noexcept;
 [none]
 * {blank}
 +
-Returns: :: `*cat_`.
+Returns: :: the error category.

 ```
 std::string message() const;
@@ -769,7 +966,7 @@ std::string message() const;
 [none]
 * {blank}
 +
-Returns: :: `cat_\->message( val_ )`.
+Returns: :: `category().message( value() )`.

 ```
 char const * message( char * buffer, std::size_t len ) const noexcept;
@@ -777,7 +974,7 @@ char const * message( char * buffer, std::size_t len ) const noexcept;
 [none]
 * {blank}
 +
-Returns: :: `cat_\->message( val_, buffer, len )`.
+Returns: :: `category().message( value(), buffer, len )`.

 ```
 constexpr bool failed() const noexcept;
@@ -785,7 +982,7 @@ constexpr bool failed() const noexcept;
 [none]
 * {blank}
 +
-Returns: :: `cat_\->failed( val_ )`.
+Returns: :: `category().failed( value() )`.

 ```
 constexpr explicit operator bool() const noexcept;
@@ -793,23 +990,13 @@ constexpr explicit operator bool() const noexcept;
 [none]
 * {blank}
 +
-Returns: :: `failed()`.
-
-```
-operator std::error_condition() const;
-```
-[none]
-* {blank}
-+
 Returns: ::
-  `std::error_condition( val_, *cat_ )`.
+  `failed()`.

-### Nonmember functions
+#### Comparisons

 ```
-constexpr bool operator==( const error_code & lhs,
-  const error_code & rhs ) noexcept;
-constexpr bool operator==( const error_condition & lhs,
+friend constexpr bool operator==( const error_condition & lhs,
  const error_condition & rhs ) noexcept;
 ```
 [none]
@@ -818,25 +1005,8 @@ constexpr bool operator==( const error_condition & lhs,
 Returns: :: `lhs.value() == rhs.value() && lhs.category() == rhs.category()`.

 ```
-bool operator==( const error_code & code,
-  const error_condition & condition ) noexcept;
-bool operator==( const error_condition & condition,
-  const error_code & code ) noexcept;
-```
-[none]
-* {blank}
-+
-Returns: :: `code.category().equivalent( code.value(), condition ) || condition.category().equivalent( code, condition.value() )`.
-
-```
-constexpr bool operator!=( const error_code & lhs,
-  const error_code & rhs ) noexcept;
-constexpr bool operator!=( const error_condition & lhs,
+friend constexpr bool operator!=( const error_condition & lhs,
  const error_condition & rhs ) noexcept;
-bool operator!=( const error_code & code,
-  const error_condition & condition ) noexcept;
-bool operator!=( const error_condition & condition,
-  const error_code & code ) noexcept;
 ```
 [none]
 * {blank}
@@ -844,53 +1014,27 @@ bool operator!=( const error_condition & condition,
 Returns: :: `!( lhs == rhs )`.

 ```
-constexpr bool operator<( const error_code & lhs,
-  const error_code & rhs ) noexcept;
-constexpr bool operator<( const error_condition & lhs,
+friend constexpr bool operator<( const error_condition & lhs,
  const error_condition & rhs ) noexcept;
 ```
 [none]
 * {blank}
 +
-Returns: :: `lhs.category() < rhs.category() || ( lhs.category() == rhs.category() && lhs.value() < rhs.value() )`.
+Returns: ::
+  `lhs.category() < rhs.category() || (lhs.category() == rhs.category() && lhs.value() < rhs.value())`.
+
+#### Conversions

 ```
-constexpr error_code make_error_code( errc::errc_t e ) noexcept;
-```
-[none]
-* {blank}
-+
-Returns: :: `error_code( e, generic_category() )`.
-
-```
-constexpr error_condition make_error_condition( errc::errc_t e ) noexcept;
-```
-[none]
-* {blank}
-+
-Returns: :: `error_condition( e, generic_category() )`.
-
-```
-template <class charT, class traits>
-  std::basic_ostream<charT, traits>&
-    operator<<( basic_ostream<charT, traits>& os, const error_code & ec );
-```
-[none]
-* {blank}
-+
-Effects: :: `os << ec.category().name() << ':' << ec.value()`.
-Returns: :: `os`.
-
-```
-std::size_t hash_value( const error_code & ec );
+operator std::error_condition() const;
 ```
 [none]
 * {blank}
 +
 Returns: ::
-  A hash value representing `ec`.
+  `std::error_condition( value(), category() )`.

-## <boost/system/system_error.hpp>
+## <boost/system/{zwsp}system_error.hpp>

 ### Class system_error

@@ -967,4 +1111,8 @@ const char * what() const noexcept;
 * {blank}
 +
 Returns: :: A null-terminated character string incorporating the arguments supplied
-  in the constructor, typically of the form `what_arg + ": " + code.message()`.
+  in the constructor, typically of the form `what_arg + ": " + code().message()`.
+
+## <boost/system.hpp>
+
+This convenience header includes all the headers previously described.
--- a/include/boost/cerrno.hpp
+++ b/include/boost/cerrno.hpp
@@ -7,325 +7,9 @@

 //  See library home page at http://www.boost.org/libs/system

-#ifndef BOOST_SYSTEM_CERRNO_HPP
-#define BOOST_SYSTEM_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
--- a/include/boost/system.hpp
+++ b/include/boost/system.hpp
@@ -0,0 +1,13 @@
+#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>
+
+#endif // #ifndef BOOST_SYSTEM_HPP_INCLUDED
--- a/include/boost/system/cygwin_error.hpp
+++ b/include/boost/system/cygwin_error.hpp
@@ -10,6 +10,13 @@
 #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.

--- a/include/boost/system/detail/cerrno.hpp
+++ b/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
--- a/include/boost/system/detail/config.hpp
+++ b/include/boost/system/detail/config.hpp
@@ -13,20 +13,10 @@

 // BOOST_SYSTEM_HAS_SYSTEM_ERROR

-#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR)
+#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR) && !defined(BOOST_NO_CXX11_HDR_ATOMIC)
 # define BOOST_SYSTEM_HAS_SYSTEM_ERROR
 #endif

-#if BOOST_WORKAROUND(BOOST_GCC, < 40600)
-// g++ 4.4's <map> is not good enough
-# undef BOOST_SYSTEM_HAS_SYSTEM_ERROR
-#endif
-
-#if defined(BOOST_NO_CXX11_HDR_MUTEX)
-// Required for thread-safe map manipulation
-# undef BOOST_SYSTEM_HAS_SYSTEM_ERROR
-#endif
-
 // BOOST_SYSTEM_NOEXCEPT
 // Retained for backward compatibility

@@ -48,4 +38,22 @@
 # 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
+
 #endif // BOOST_SYSTEM_DETAIL_CONFIG_HPP_INCLUDED
--- a/include/boost/system/detail/enable_if.hpp
+++ b/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
--- a/include/boost/system/detail/errc.hpp
+++ b/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
--- a/include/boost/system/detail/error_category.hpp
+++ b/include/boost/system/detail/error_category.hpp
@@ -0,0 +1,194 @@
+#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
+
+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 );
+
+#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_;
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    mutable std::atomic< boost::system::detail::std_category* > ps_;
+
+#else
+
+    boost::system::detail::std_category* ps_;
+
+#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 ), ps_()
+    {
+    }
+
+    explicit BOOST_SYSTEM_CONSTEXPR error_category( boost::ulong_long_type id ) BOOST_NOEXCEPT: id_( id ), ps_()
+    {
+    }
+
+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)
+# 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_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 ) + 0x257EDF0D;
+static const boost::ulong_long_type system_category_id = ( boost::ulong_long_type( 0x8FAFD21E ) << 32 ) + 0x25C5E09B;
+
+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
--- a/include/boost/system/detail/error_category_impl.hpp
+++ b/include/boost/system/detail/error_category_impl.hpp
@@ -0,0 +1,137 @@
+#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/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 *this == code.category() && code.value() == condition;
+}
+
+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( ... )
+    {
+        return "Message text unavailable";
+    }
+#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.hpp>
+
+inline boost::system::error_category::operator std::error_category const & () const
+{
+    if( id_ == boost::system::detail::system_category_id )
+    {
+        static const boost::system::detail::std_category system_instance( this, 0x1F4D7 );
+        return system_instance;
+    }
+
+    if( id_ == boost::system::detail::generic_category_id )
+    {
+        static const boost::system::detail::std_category generic_instance( this, 0x1F4D3 );
+        return generic_instance;
+    }
+
+    boost::system::detail::std_category* p = ps_.load( std::memory_order_acquire );
+
+    if( p != 0 )
+    {
+        return *p;
+    }
+
+    boost::system::detail::std_category* q = new detail::std_category( this, 0 );
+
+    if( ps_.compare_exchange_strong( p, q, std::memory_order_release, std::memory_order_acquire ) )
+    {
+        return *q;
+    }
+    else
+    {
+        delete q;
+        return *p;
+    }
+}
+
+#endif // #if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_ERROR_CATEGORY_IMPL_HPP_INCLUDED
--- a/include/boost/system/detail/error_code.hpp
+++ b/include/boost/system/detail/error_code.hpp
@@ -0,0 +1,215 @@
+#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, 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/system_category.hpp>
+#include <boost/system/detail/enable_if.hpp>
+#include <boost/system/is_error_code_enum.hpp>
+#include <boost/system/detail/config.hpp>
+#include <boost/cstdint.hpp>
+#include <boost/config.hpp>
+#include <ostream>
+
+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.
+
+class error_code
+{
+private:
+
+    int val_;
+    bool failed_;
+    const error_category * cat_;
+
+public:
+
+    // constructors:
+
+    BOOST_SYSTEM_CONSTEXPR error_code() BOOST_NOEXCEPT:
+        val_( 0 ), failed_( false ), cat_( &system_category() )
+    {
+    }
+
+    BOOST_SYSTEM_CONSTEXPR error_code( int val, const error_category & cat ) BOOST_NOEXCEPT:
+        val_( val ), failed_( detail::failed_impl( val, cat ) ), cat_( &cat )
+    {
+    }
+
+    template<class ErrorCodeEnum> BOOST_SYSTEM_CONSTEXPR error_code( ErrorCodeEnum e,
+        typename detail::enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type* = 0 ) BOOST_NOEXCEPT
+    {
+        *this = make_error_code( e );
+    }
+
+    // modifiers:
+
+    BOOST_SYSTEM_CONSTEXPR void assign( int val, const error_category & cat ) BOOST_NOEXCEPT
+    {
+        val_ = val;
+        failed_ = detail::failed_impl( val, cat );
+        cat_ = &cat;
+    }
+
+    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
+    {
+        val_ = 0;
+        failed_ = false;
+        cat_ = &system_category();
+    }
+
+    // observers:
+
+    BOOST_SYSTEM_CONSTEXPR int value() const BOOST_NOEXCEPT
+    {
+        return val_;
+    }
+
+    BOOST_SYSTEM_CONSTEXPR const error_category & category() const BOOST_NOEXCEPT
+    {
+        return *cat_;
+    }
+
+    error_condition default_error_condition() const BOOST_NOEXCEPT
+    {
+        return cat_->default_error_condition( value() );
+    }
+
+    std::string message() const
+    {
+        return cat_->message( value() );
+    }
+
+    char const * message( char * buffer, std::size_t len ) const BOOST_NOEXCEPT
+    {
+        return cat_->message( value(), buffer, len );
+    }
+
+    BOOST_SYSTEM_CONSTEXPR bool failed() const BOOST_NOEXCEPT
+    {
+        return failed_;
+    }
+
+#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_code & lhs, const error_code & rhs ) BOOST_NOEXCEPT
+    {
+        return lhs.val_ == rhs.val_ && *lhs.cat_ == *rhs.cat_;
+    }
+
+    BOOST_SYSTEM_CONSTEXPR inline friend bool operator<( const error_code & lhs, const error_code & rhs ) BOOST_NOEXCEPT
+    {
+        return *lhs.cat_ < *rhs.cat_ || ( *lhs.cat_ == *rhs.cat_ && lhs.val_ < rhs.val_ );
+    }
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    operator std::error_code () const
+    {
+        return std::error_code( value(), category() );
+    }
+
+#endif
+};
+
+BOOST_SYSTEM_CONSTEXPR inline bool operator!=( const error_code & lhs, const error_code & rhs ) BOOST_NOEXCEPT
+{
+    return !( lhs == rhs );
+}
+
+template<class Ch, class Tr>
+    inline std::basic_ostream<Ch, Tr>&
+    operator<< (std::basic_ostream<Ch, Tr>& os, error_code const & ec)
+{
+    os << ec.category().name() << ':' << ec.value();
+    return os;
+}
+
+inline std::size_t hash_value( error_code const & ec )
+{
+    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
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_ERROR_CODE_HPP_INCLUDED
--- a/include/boost/system/detail/error_condition.hpp
+++ b/include/boost/system/detail/error_condition.hpp
@@ -0,0 +1,212 @@
+#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, 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.hpp>
+#include <boost/system/detail/enable_if.hpp>
+#include <boost/system/detail/is_same.hpp>
+#include <boost/system/detail/errc.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_;
+
+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 generic_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 generic_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
+    {
+        return lhs.val_ == rhs.val_ && lhs.category() == rhs.category();
+    }
+
+    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
+    {
+        return std::error_condition( value(), category() );
+    }
+
+#endif
+};
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_ERROR_CONDITION_HPP_INCLUDED
--- a/include/boost/system/detail/generic_category.hpp
+++ b/include/boost/system/detail/generic_category.hpp
@@ -1,13 +1,19 @@
-// Implementation details of generic_error_category
-//
-// 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
+#ifndef BOOST_SYSTEM_DETAIL_GENERIC_CATEGORY_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_GENERIC_CATEGORY_HPP_INCLUDED

-#include <cstring>
+//  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
 {
@@ -18,84 +24,100 @@ namespace system
 namespace detail
 {

-#if defined(__GLIBC__)
+// generic_error_category

-// glibc has two incompatible strerror_r definitions
+#if ( defined( BOOST_GCC ) && BOOST_GCC >= 40600 ) || defined( BOOST_CLANG )
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
+#endif

-inline char const * strerror_r_helper( char const * r, char const * ) BOOST_NOEXCEPT
+class BOOST_SYMBOL_VISIBLE generic_error_category: public error_category
 {
-    return r;
-}
+public:

-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
-
-// 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 )
+    BOOST_SYSTEM_CONSTEXPR generic_error_category() BOOST_NOEXCEPT:
+        error_category( detail::generic_category_id )
    {
-        return buffer;
    }

-    if( len == 1 )
+    const char * name() const BOOST_NOEXCEPT BOOST_OVERRIDE
    {
-        buffer[0] = 0;
-        return buffer;
+        return "generic";
    }

-    char const * m = std::strerror( ev );
+    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( m == 0 ) return "Unknown error";
+#if ( defined( BOOST_GCC ) && BOOST_GCC >= 40600 ) || defined( BOOST_CLANG )
+#pragma GCC diagnostic pop
+#endif

-    std::strncpy( buffer, m, len - 1 );
-    buffer[ len-1 ] = 0;
+// generic_error_category::message

-    return buffer;
+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 );
 }

-# if defined( BOOST_MSVC )
-#  pragma warning( pop )
-# elif defined(__clang__) && defined(__has_warning)
-#  pragma clang diagnostic pop
-# endif
+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
--- a/include/boost/system/detail/generic_category_message.hpp
+++ b/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
--- a/include/boost/system/detail/is_same.hpp
+++ b/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
--- a/include/boost/system/detail/std_interoperability.hpp
+++ b/include/boost/system/detail/std_interoperability.hpp
@@ -1,16 +1,20 @@
+#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 Peter Dimov
+// 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 <boost/system/detail/error_condition.hpp>
+#include <boost/system/detail/error_code.hpp>
+#include <boost/system/detail/generic_category.hpp>
 #include <system_error>
-#include <map>
-#include <memory>
-#include <mutex>

 //

@@ -66,54 +70,6 @@ public:
    bool equivalent( const std::error_code & code, int condition ) const BOOST_NOEXCEPT BOOST_OVERRIDE;
 };

-#if !defined(__SUNPRO_CC) // trailing __global is not supported
-inline std::error_category const & to_std_category( boost::system::error_category const & cat ) BOOST_SYMBOL_VISIBLE;
-#endif
-
-struct cat_ptr_less
-{
-    bool operator()( boost::system::error_category const * p1, boost::system::error_category const * p2 ) const BOOST_NOEXCEPT
-    {
-        return *p1 < *p2;
-    }
-};
-
-inline std::error_category const & to_std_category( boost::system::error_category const & cat )
-{
-    if( cat == boost::system::system_category() )
-    {
-        static const std_category system_instance( &cat, 0x1F4D7 );
-        return system_instance;
-    }
-    else if( cat == boost::system::generic_category() )
-    {
-        static const std_category generic_instance( &cat, 0x1F4D3 );
-        return generic_instance;
-    }
-    else
-    {
-        typedef std::map< boost::system::error_category const *, std::unique_ptr<std_category>, cat_ptr_less > map_type;
-
-        static map_type map_;
-        static std::mutex map_mx_;
-
-        std::lock_guard<std::mutex> guard( map_mx_ );
-
-        map_type::iterator i = map_.find( &cat );
-
-        if( i == map_.end() )
-        {
-            std::unique_ptr<std_category> p( new std_category( &cat, 0 ) );
-
-            std::pair<map_type::iterator, bool> r = map_.insert( map_type::value_type( &cat, std::move( p ) ) );
-
-            i = r.first;
-        }
-
-        return *i->second;
-    }
-}
-
 inline bool std_category::equivalent( int code, const std::error_condition & condition ) const BOOST_NOEXCEPT
 {
    if( condition.category() == *this )
@@ -163,6 +119,7 @@ inline bool std_category::equivalent( const std::error_code & code, int conditio
        boost::system::error_code bc( code.value(), *pc2->pc_ );
        return pc_->equivalent( bc, condition );
    }
+
 #endif

    else if( *pc_ == boost::system::generic_category() )
@@ -180,3 +137,5 @@ inline bool std_category::equivalent( const std::error_code & code, int conditio
 } // namespace system

 } // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_STD_CATEGORY_HPP_INCLUDED
--- a/include/boost/system/detail/system_category.hpp
+++ b/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
--- a/include/boost/system/detail/system_category_condition_win32.hpp
+++ b/include/boost/system/detail/system_category_condition_win32.hpp
@@ -0,0 +1,147 @@
+#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_UNIT_: return no_such_device;
+    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 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_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
--- a/include/boost/system/detail/system_category_impl.hpp
+++ b/include/boost/system/detail/system_category_impl.hpp
@@ -0,0 +1,73 @@
+#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/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_message_win32.hpp>
+#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 ) );
+    }
+}
+
+inline std::string boost::system::detail::system_error_category::message( int ev ) const
+{
+    return system_category_message_win32( ev );
+}
+
+inline char const * boost::system::detail::system_error_category::message( int ev, char * buffer, std::size_t len ) const BOOST_NOEXCEPT
+{
+    return system_category_message_win32( ev, buffer, len );
+}
+
+#else // #if defined(BOOST_WINDOWS_API)
+
+#include <boost/system/detail/generic_category_message.hpp>
+
+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 ) );
+}
+
+inline std::string boost::system::detail::system_error_category::message( int ev ) const
+{
+    return generic_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 generic_error_category_message( ev, buffer, len );
+}
+
+#endif // #if defined(BOOST_WINDOWS_API)
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_SYSTEM_CATEGORY_IMPL_HPP_INCLUDED
--- a/include/boost/system/detail/system_category_message_win32.hpp
+++ b/include/boost/system/detail/system_category_message_win32.hpp
@@ -0,0 +1,233 @@
+#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/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
+{
+
+#if ( defined(_MSC_VER) && _MSC_VER < 1900 ) || ( defined(__MINGW32__) && !defined(__MINGW64_VERSION_MAJOR) )
+
+inline char const * unknown_message_win32( int ev, char * buffer, std::size_t len )
+{
+# if defined( BOOST_MSVC )
+#  pragma warning( push )
+#  pragma warning( disable: 4996 )
+# endif
+
+    _snprintf( buffer, len - 1, "Unknown error (%d)", ev );
+
+    buffer[ len - 1 ] = 0;
+    return buffer;
+
+# if defined( BOOST_MSVC )
+#  pragma warning( pop )
+# endif
+}
+
+#else
+
+inline char const * unknown_message_win32( int ev, char * buffer, std::size_t len )
+{
+    std::snprintf( buffer, len, "Unknown error (%d)", ev );
+    return buffer;
+}
+
+#endif
+
+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
--- a/include/boost/system/detail/system_category_posix.hpp
+++ b/include/boost/system/detail/system_category_posix.hpp
@@ -1,132 +0,0 @@
-// POSIX-specific implementation details of system_error_category
-//
-// 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
-
-namespace boost
-{
-
-namespace system
-{
-
-namespace detail
-{
-
-inline bool is_generic_value( int ev ) BOOST_NOEXCEPT
-{
-    using namespace errc;
-
-    static int const gen[] =
-    {
-        success,
-        address_family_not_supported,
-        address_in_use,
-        address_not_available,
-        already_connected,
-        argument_list_too_long,
-        argument_out_of_domain,
-        bad_address,
-        bad_file_descriptor,
-        bad_message,
-        broken_pipe,
-        connection_aborted,
-        connection_already_in_progress,
-        connection_refused,
-        connection_reset,
-        cross_device_link,
-        destination_address_required,
-        device_or_resource_busy,
-        directory_not_empty,
-        executable_format_error,
-        file_exists,
-        file_too_large,
-        filename_too_long,
-        function_not_supported,
-        host_unreachable,
-        identifier_removed,
-        illegal_byte_sequence,
-        inappropriate_io_control_operation,
-        interrupted,
-        invalid_argument,
-        invalid_seek,
-        io_error,
-        is_a_directory,
-        message_size,
-        network_down,
-        network_reset,
-        network_unreachable,
-        no_buffer_space,
-        no_child_process,
-        no_link,
-        no_lock_available,
-        no_message_available,
-        no_message,
-        no_protocol_option,
-        no_space_on_device,
-        no_stream_resources,
-        no_such_device_or_address,
-        no_such_device,
-        no_such_file_or_directory,
-        no_such_process,
-        not_a_directory,
-        not_a_socket,
-        not_a_stream,
-        not_connected,
-        not_enough_memory,
-        not_supported,
-        operation_canceled,
-        operation_in_progress,
-        operation_not_permitted,
-        operation_not_supported,
-        operation_would_block,
-        owner_dead,
-        permission_denied,
-        protocol_error,
-        protocol_not_supported,
-        read_only_file_system,
-        resource_deadlock_would_occur,
-        resource_unavailable_try_again,
-        result_out_of_range,
-        state_not_recoverable,
-        stream_timeout,
-        text_file_busy,
-        timed_out,
-        too_many_files_open_in_system,
-        too_many_files_open,
-        too_many_links,
-        too_many_symbolic_link_levels,
-        value_too_large,
-        wrong_protocol_type
-    };
-
-    int const n = sizeof( gen ) / sizeof( gen[0] );
-
-    for( int i = 0; i < n; ++i )
-    {
-        if( ev == gen[ i ] ) return true;
-    }
-
-    return false;
-}
-
-inline error_condition system_category_default_error_condition_posix( int ev ) BOOST_NOEXCEPT
-{
-    if( is_generic_value( ev ) )
-    {
-        return error_condition( ev, generic_category() );
-    }
-    else
-    {
-        return error_condition( ev, system_category() );
-    }
-}
-
-} // namespace detail
-
-} // namespace system
-
-} // namespace boost
--- a/include/boost/system/detail/system_category_win32.hpp
+++ b/include/boost/system/detail/system_category_win32.hpp
@@ -1,341 +0,0 @@
-// Windows implementation of system_error_category
-//
-// 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/winapi/error_codes.hpp>
-#include <boost/winapi/error_handling.hpp>
-#include <boost/winapi/character_code_conversion.hpp>
-#include <boost/winapi/local_memory.hpp>
-#include <cstdio>
-
-//
-
-namespace boost
-{
-
-namespace system
-{
-
-namespace detail
-{
-
-#if ( defined(_MSC_VER) && _MSC_VER < 1900 ) || ( defined(__MINGW32__) && !defined(__MINGW64_VERSION_MAJOR) )
-
-inline char const * unknown_message_win32( int ev, char * buffer, std::size_t len )
-{
-# if defined( BOOST_MSVC )
-#  pragma warning( push )
-#  pragma warning( disable: 4996 )
-# endif
-
-    _snprintf( buffer, len - 1, "Unknown error (%d)", ev );
-
-    buffer[ len - 1 ] = 0;
-    return buffer;
-
-# if defined( BOOST_MSVC )
-#  pragma warning( pop )
-# endif
-}
-
-#else
-
-inline char const * unknown_message_win32( int ev, char * buffer, std::size_t len )
-{
-    std::snprintf( buffer, len, "Unknown error (%d)", ev );
-    return buffer;
-}
-
-#endif
-
-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;
-}
-
-inline error_condition system_category_default_error_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 make_error_condition( success );
-
-    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_CONNECTION_ABORTED_: return make_error_condition( connection_aborted );
-    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 );
-
-    default: return error_condition( ev, system_category() );
-    }
-}
-
-} // namespace detail
-
-} // namespace system
-
-} // namespace boost
--- a/include/boost/system/detail/throws.hpp
+++ b/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
--- a/include/boost/system/errc.hpp
+++ b/include/boost/system/errc.hpp
@@ -0,0 +1,50 @@
+#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/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() );
+}
+
+// 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
--- a/include/boost/system/error_category.hpp
+++ b/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
--- a/include/boost/system/error_code.hpp
+++ b/include/boost/system/error_code.hpp
@@ -10,25 +10,14 @@
 //
 //  See library home page at http://www.boost.org/libs/system

-#include <boost/system/api_config.hpp>
-#include <boost/system/detail/config.hpp>
-#include <boost/cstdint.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>
 #include <boost/config.hpp>
-#include <ostream>
-#include <string>
-#include <functional>
-#include <cstring>
-
-// TODO: undef these macros if not already defined
-#include <boost/cerrno.hpp>
-
-#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
-# include <system_error>
-#endif
-
-#if !defined(BOOST_POSIX_API) && !defined(BOOST_WINDOWS_API)
-#  error BOOST_POSIX_API or BOOST_WINDOWS_API must be defined
-#endif

 namespace boost
 {
@@ -36,722 +25,8 @@ namespace boost
 namespace system
 {

-class error_code;         // values defined by the operating system
-class error_condition;    // portable generic values defined below, but ultimately
-                          // based on the POSIX standard
-
-// "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_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;
-};
-
-// class error_category
-#if ( defined( BOOST_GCC ) && BOOST_GCC >= 40600 ) || defined( BOOST_CLANG )
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
-#endif
-
-#ifdef BOOST_MSVC
-#pragma warning( push )
-// 'this' : used in base member initializer list
-#pragma warning( disable: 4355 )
-#endif
-
-std::size_t hash_value( error_code const & ec );
-
-class BOOST_SYMBOL_VISIBLE error_category
-{
-private:
-
-    friend std::size_t hash_value( error_code const & ec );
-
-#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_;
-
-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 )
-    {
-    }
-
-    explicit BOOST_SYSTEM_CONSTEXPR error_category( boost::ulong_long_type id ) BOOST_NOEXCEPT: id_( id )
-    {
-    }
-
-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;
-
-    BOOST_SYSTEM_CONSTEXPR bool operator==( const error_category & rhs ) const BOOST_NOEXCEPT
-    {
-        return rhs.id_ == 0? this == &rhs: id_ == rhs.id_;
-    }
-
-    BOOST_SYSTEM_CONSTEXPR bool operator!=( const error_category & rhs ) const BOOST_NOEXCEPT
-    {
-        return !( *this == rhs );
-    }
-
-    BOOST_SYSTEM_CONSTEXPR bool operator<( const error_category & rhs ) const BOOST_NOEXCEPT
-    {
-        if( id_ < rhs.id_ )
-        {
-            return true;
-        }
-
-        if( id_ > rhs.id_ )
-        {
-            return false;
-        }
-
-        if( rhs.id_ != 0 )
-        {
-            return false; // equal
-        }
-
-        return std::less<error_category const *>()( this, &rhs );
-    }
-
-#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
-
-    operator std::error_category const & () const;
-
-#endif
-};
-
-#ifdef BOOST_MSVC
-#pragma warning( pop )
-#endif
-
-// predefined error categories
-
-namespace detail
-{
-
-class BOOST_SYMBOL_VISIBLE generic_error_category: public error_category
-{
-public:
-
-    // clang++ 3.8 and below: initialization of const object
-    // requires a user-provided default constructor
-    BOOST_SYSTEM_CONSTEXPR generic_error_category() BOOST_NOEXCEPT:
-        error_category( ( boost::ulong_long_type( 0xB2AB117A ) << 32 ) + 0x257EDF0D )
-    {
-    }
-
-    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;
-};
-
-class BOOST_SYMBOL_VISIBLE system_error_category: public error_category
-{
-public:
-
-    BOOST_SYSTEM_CONSTEXPR system_error_category() BOOST_NOEXCEPT:
-        error_category( ( boost::ulong_long_type( 0x8FAFD21E ) << 32 ) + 0x25C5E09B )
-    {
-    }
-
-    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;
-};
-
-} // namespace detail
-
-#if ( defined( BOOST_GCC ) && BOOST_GCC >= 40600 ) || defined( BOOST_CLANG )
-#pragma GCC diagnostic pop
-#endif
-
-// generic_category(), system_category()
-
-#if defined(BOOST_SYSTEM_HAS_CONSTEXPR)
-
-namespace detail
-{
-
-template<class T> struct BOOST_SYMBOL_VISIBLE cat_holder
-{
-    static constexpr system_error_category system_category_instance{};
-    static constexpr generic_error_category generic_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 cat_holder<T>::system_category_instance;
-template<class T> constexpr generic_error_category cat_holder<T>::generic_category_instance;
-#endif
-
-} // namespace detail
-
-constexpr error_category const & system_category() BOOST_NOEXCEPT
-{
-    return detail::cat_holder<void>::system_category_instance;
-}
-
-constexpr error_category const & generic_category() BOOST_NOEXCEPT
-{
-    return detail::cat_holder<void>::generic_category_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;
-inline error_category const & generic_category() BOOST_NOEXCEPT BOOST_SYMBOL_VISIBLE;
-#endif
-
-inline error_category const & system_category() BOOST_NOEXCEPT
-{
-    static const detail::system_error_category system_category_instance;
-    return system_category_instance;
-}
-
-inline error_category const & generic_category() BOOST_NOEXCEPT
-{
-    static const detail::generic_error_category generic_category_instance;
-    return generic_category_instance;
-}
-
-#endif // #if defined(BOOST_SYSTEM_HAS_CONSTEXPR)
-
-// deprecated synonyms
-
-#ifdef BOOST_SYSTEM_ENABLE_DEPRECATED
-
-inline const error_category & get_system_category() { return system_category(); }
-inline const error_category & get_generic_category() { return generic_category(); }
-inline const error_category & get_posix_category() { return generic_category(); }
-static const error_category & posix_category BOOST_ATTRIBUTE_UNUSED = generic_category();
-static const error_category & errno_ecat BOOST_ATTRIBUTE_UNUSED = generic_category();
-static const error_category & native_ecat BOOST_ATTRIBUTE_UNUSED = system_category();
-
-#endif
-
-// enable_if
-
-namespace detail
-{
-
-template<bool C, class T = void> struct enable_if
-{
-    typedef T type;
-};
-
-template<class T> struct enable_if<false, T>
-{
-};
-
-// failed_impl
-
-#if !defined(BOOST_SYSTEM_HAS_CONSTEXPR)
-
-inline bool failed_impl( int ev, error_category const & cat )
-{
-    return cat.failed( ev );
-}
-
-#else
-
-BOOST_SYSTEM_CONSTEXPR inline bool failed_impl( int ev, error_category const & cat )
-{
-    if( cat == system_category() || cat == generic_category() )
-    {
-        return ev != 0;
-    }
-    else
-    {
-        return cat.failed( ev );
-    }
-}
-
-#endif
-
-} // namespace detail
-
-// class error_condition
-
-// error_conditions are portable, error_codes are system or library specific
-
-class error_condition
-{
-private:
-
-    int val_;
-    bool failed_;
-    error_category const * cat_;
-
-public:
-
-    // constructors:
-
-    BOOST_SYSTEM_CONSTEXPR error_condition() BOOST_NOEXCEPT:
-        val_( 0 ), failed_( false ), cat_( &generic_category() )
-    {
-    }
-
-    BOOST_SYSTEM_CONSTEXPR error_condition( int val, const error_category & cat ) BOOST_NOEXCEPT:
-        val_( val ), failed_( detail::failed_impl( val, cat ) ), cat_( &cat )
-    {
-    }
-
-    template<class ErrorConditionEnum> BOOST_SYSTEM_CONSTEXPR error_condition( ErrorConditionEnum e,
-        typename detail::enable_if<is_error_condition_enum<ErrorConditionEnum>::value>::type* = 0) BOOST_NOEXCEPT
-    {
-        *this = make_error_condition( e );
-    }
-
-    // modifiers:
-
-    BOOST_SYSTEM_CONSTEXPR void assign( int val, const error_category & cat ) BOOST_NOEXCEPT
-    {
-        val_ = val;
-        failed_ = detail::failed_impl( val, cat );
-        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 = make_error_condition( val );
-        return *this;
-    }
-
-    BOOST_SYSTEM_CONSTEXPR void clear() BOOST_NOEXCEPT
-    {
-        val_ = 0;
-        failed_ = false;
-        cat_ = &generic_category();
-    }
-
-    // observers:
-
-    BOOST_SYSTEM_CONSTEXPR int value() const BOOST_NOEXCEPT
-    {
-        return val_;
-    }
-
-    BOOST_SYSTEM_CONSTEXPR const error_category & category() const BOOST_NOEXCEPT
-    {
-        return *cat_;
-    }
-
-    std::string message() const
-    {
-        return cat_->message( value() );
-    }
-
-    char const * message( char * buffer, std::size_t len ) const BOOST_NOEXCEPT
-    {
-        return cat_->message( value(), buffer, len );
-    }
-
-    BOOST_SYSTEM_CONSTEXPR bool failed() const BOOST_NOEXCEPT
-    {
-        return failed_;
-    }
-
-#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
-    {
-        return lhs.val_ == rhs.val_ && *lhs.cat_ == *rhs.cat_;
-    }
-
-    BOOST_SYSTEM_CONSTEXPR inline friend bool operator<( const error_condition & lhs, const error_condition & rhs ) BOOST_NOEXCEPT
-    {
-        return *lhs.cat_ < *rhs.cat_ || ( *lhs.cat_ == *rhs.cat_ && lhs.val_ < rhs.val_ );
-    }
-
-#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
-
-    operator std::error_condition () const
-    {
-        return std::error_condition( value(), category() );
-    }
-
-#endif
-};
-
-//  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
-{
-private:
-
-    int val_;
-    bool failed_;
-    const error_category * cat_;
-
-public:
-
-    // constructors:
-
-    BOOST_SYSTEM_CONSTEXPR error_code() BOOST_NOEXCEPT:
-        val_( 0 ), failed_( false ), cat_( &system_category() )
-    {
-    }
-
-    BOOST_SYSTEM_CONSTEXPR error_code( int val, const error_category & cat ) BOOST_NOEXCEPT:
-        val_( val ), failed_( detail::failed_impl( val, cat ) ), cat_( &cat )
-    {
-    }
-
-    template<class ErrorCodeEnum> BOOST_SYSTEM_CONSTEXPR error_code( ErrorCodeEnum e,
-        typename detail::enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type* = 0 ) BOOST_NOEXCEPT
-    {
-        *this = make_error_code( e );
-    }
-
-    // modifiers:
-
-    BOOST_SYSTEM_CONSTEXPR void assign( int val, const error_category & cat ) BOOST_NOEXCEPT
-    {
-        val_ = val;
-        failed_ = detail::failed_impl( val, cat );
-        cat_ = &cat;
-    }
-
-    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
-    {
-        val_ = 0;
-        failed_ = false;
-        cat_ = &system_category();
-    }
-
-    // observers:
-
-    BOOST_SYSTEM_CONSTEXPR int value() const BOOST_NOEXCEPT
-    {
-        return val_;
-    }
-
-    BOOST_SYSTEM_CONSTEXPR const error_category & category() const BOOST_NOEXCEPT
-    {
-        return *cat_;
-    }
-
-    error_condition default_error_condition() const BOOST_NOEXCEPT
-    {
-        return cat_->default_error_condition( value() );
-    }
-
-    std::string message() const
-    {
-        return cat_->message( value() );
-    }
-
-    char const * message( char * buffer, std::size_t len ) const BOOST_NOEXCEPT
-    {
-        return cat_->message( value(), buffer, len );
-    }
-
-    BOOST_SYSTEM_CONSTEXPR bool failed() const BOOST_NOEXCEPT
-    {
-        return failed_;
-    }
-
-#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_code & lhs, const error_code & rhs ) BOOST_NOEXCEPT
-    {
-        return lhs.val_ == rhs.val_ && *lhs.cat_ == *rhs.cat_;
-    }
-
-    BOOST_SYSTEM_CONSTEXPR inline friend bool operator<( const error_code & lhs, const error_code & rhs ) BOOST_NOEXCEPT
-    {
-        return *lhs.cat_ < *rhs.cat_ || ( *lhs.cat_ == *rhs.cat_ && lhs.val_ < rhs.val_ );
-    }
-
-#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
-
-    operator std::error_code () const
-    {
-        return std::error_code( value(), category() );
-    }
-
-#endif
-};
-
-}  // 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();
-}
-
 // non-member functions of error_code and error_condition

-namespace system
-{
-
-BOOST_SYSTEM_CONSTEXPR inline bool operator!=( const error_code & lhs, const error_code & rhs ) BOOST_NOEXCEPT
-{
-    return !( lhs == rhs );
-}
-
-BOOST_SYSTEM_CONSTEXPR inline bool operator!=( const error_condition & lhs, const error_condition & rhs ) BOOST_NOEXCEPT
-{
-    return !( lhs == rhs );
-}
-
 inline bool operator==( const error_code & code, const error_condition & condition ) BOOST_NOEXCEPT
 {
    return code.category().equivalent( code.value(), condition ) || condition.category().equivalent( code, condition.value() );
@@ -772,201 +47,8 @@ inline bool operator!=( const error_condition & lhs, const error_code & rhs ) BO
    return !( lhs == rhs );
 }

-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( error_code const & ec )
-{
-    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 );
-}
-
-// 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() );
-}
-
-// implicit conversion:
-BOOST_SYSTEM_CONSTEXPR inline error_condition make_error_condition( errc_t e ) BOOST_NOEXCEPT
-{
-    return error_condition( e, generic_category() );
-}
-
-} // namespace errc
-
-// 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 *this == code.category() && code.value() == condition;
-}
-
-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( ... )
-    {
-        return "Message text unavailable";
-    }
-#endif
-}
-
-inline bool error_category::failed( int ev ) const BOOST_NOEXCEPT
-{
-    return ev != 0;
-}
-
 } // namespace system

 } // namespace boost

-// generic_error_category implementation
-
-#include <boost/system/detail/generic_category.hpp>
-
-inline std::string boost::system::detail::generic_error_category::message( int ev ) const
-{
-    return generic_error_category_message( ev );
-}
-
-inline char const * boost::system::detail::generic_error_category::message( int ev, char * buffer, std::size_t len ) const BOOST_NOEXCEPT
-{
-    return generic_error_category_message( ev, buffer, len );
-}
-
-// system_error_category implementation
-
-#if defined(BOOST_WINDOWS_API)
-
-#include <boost/system/detail/system_category_win32.hpp>
-
-inline boost::system::error_condition boost::system::detail::system_error_category::default_error_condition( int ev ) const BOOST_NOEXCEPT
-{
-    return system_category_default_error_condition_win32( ev );
-}
-
-inline std::string boost::system::detail::system_error_category::message( int ev ) const
-{
-    return system_category_message_win32( ev );
-}
-
-inline char const * boost::system::detail::system_error_category::message( int ev, char * buffer, std::size_t len ) const BOOST_NOEXCEPT
-{
-    return system_category_message_win32( ev, buffer, len );
-}
-
-#else // #if defined(BOOST_WINDOWS_API)
-
-#include <boost/system/detail/system_category_posix.hpp>
-
-inline boost::system::error_condition boost::system::detail::system_error_category::default_error_condition( int ev ) const BOOST_NOEXCEPT
-{
-    return system_category_default_error_condition_posix( ev );
-}
-
-inline std::string boost::system::detail::system_error_category::message( int ev ) const
-{
-    return generic_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 generic_error_category_message( ev, buffer, len );
-}
-
-#endif // #if defined(BOOST_WINDOWS_API)
-
-// interoperability with std::error_code, std::error_condition
-
-#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
-
-#include <boost/system/detail/std_interoperability.hpp>
-
-inline boost::system::error_category::operator std::error_category const & () const
-{
-    return boost::system::detail::to_std_category( *this );
-}
-
-#endif // #if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
-
 #endif // BOOST_SYSTEM_ERROR_CODE_HPP_INCLUDED
--- a/include/boost/system/error_condition.hpp
+++ b/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
--- a/include/boost/system/generic_category.hpp
+++ b/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
--- a/include/boost/system/is_error_code_enum.hpp
+++ b/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
--- a/include/boost/system/is_error_condition_enum.hpp
+++ b/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
--- a/include/boost/system/linux_error.hpp
+++ b/include/boost/system/linux_error.hpp
@@ -10,6 +10,13 @@
 #ifndef BOOST_SYSTEM_LINUX_ERROR_HPP
 #define BOOST_SYSTEM_LINUX_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.

--- a/include/boost/system/system_category.hpp
+++ b/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
--- a/include/boost/system/windows_error.hpp
+++ b/include/boost/system/windows_error.hpp
@@ -18,16 +18,6 @@
 #ifdef BOOST_WINDOWS_API

 #include <boost/system/error_code.hpp>
-
-//// 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
-
 #include <boost/winapi/error_codes.hpp>

 namespace boost
@@ -82,7 +72,8 @@ namespace boost
        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_,
+        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_,
@@ -94,7 +85,7 @@ namespace boost
        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_,
+        disk_full = boost::winapi::ERROR_DISK_FULL_,
        // ...
        lock_failed = boost::winapi::ERROR_LOCK_FAILED_,
        busy = boost::winapi::ERROR_BUSY_,
--- a/meta/libraries.json
+++ b/meta/libraries.json
@@ -7,5 +7,6 @@
    "description": "Operating system support, including the diagnostics support that will be part of the C++0x standard library.",
    "category": [
        "System"
-    ]
+    ],
+    "cxxstd": "03"
 }
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -56,7 +56,7 @@ 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 ;
+compile failed_constexpr_test.cpp : <toolset>gcc,<undefined-sanitizer>norecover:<build>no ;

 # Quick (CI) test
 run quick.cpp ;
@@ -73,3 +73,19 @@ lib std_single_instance_lib2 : std_single_instance_2.cpp : <link>shared:<define>
 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 ;
--- a/test/cmake_install_test/CMakeLists.txt
+++ b/test/cmake_install_test/CMakeLists.txt
@@ -7,12 +7,11 @@ cmake_minimum_required(VERSION 3.5...3.16)
 project(cmake_install_test LANGUAGES CXX)

 find_package(boost_system REQUIRED)
-find_package(boost_core REQUIRED)

-add_executable(quick ../quick.cpp)
-target_link_libraries(quick Boost::system Boost::core)
+add_executable(main main.cpp)
+target_link_libraries(main Boost::system)

 enable_testing()
-add_test(quick quick)
+add_test(main main)

 add_custom_target(check COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure -C $<CONFIG>)
--- a/test/cmake_install_test/main.cpp
+++ b/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.message() );
+}
--- a/test/cygwin_error_test.cpp
+++ b/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
--- a/test/errc_test.cpp
+++ b/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();
+}
--- a/test/errc_test2.cpp
+++ b/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();
+}
--- a/test/error_category_test2.cpp
+++ b/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();
+}
--- a/test/error_code_test.cpp
+++ b/test/error_code_test.cpp
@@ -11,11 +11,8 @@

 #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>
@@ -294,29 +291,7 @@ int main( int, char ** )
  BOOST_TEST( ec.default_error_condition().value() == errc::permission_denied );
  BOOST_TEST( ec.default_error_condition().category() == generic_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
-
 #endif
  
  return ::boost::report_errors();
 }
-
-
--- a/test/error_condition_test.cpp
+++ b/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();
+}
--- a/test/error_condition_test2.cpp
+++ b/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();
+}
--- a/test/failed_constexpr_test.cpp
+++ b/test/failed_constexpr_test.cpp
@@ -35,16 +35,28 @@ BOOST_STATIC_ASSERT( !ec3 );

 constexpr error_condition en1( 1, system_category() );

+#if __GNUC__ == 7 && __cplusplus == 201703L
+// `cat_ != 0` is not a constant expression
+#else
+
 BOOST_STATIC_ASSERT( en1.failed() );
 BOOST_STATIC_ASSERT( en1 );
 BOOST_STATIC_ASSERT( !!en1 );

+#endif
+
 constexpr error_condition en2( 2, generic_category() );

+#if __GNUC__ == 7 && __cplusplus == 201703L
+// `cat_ != 0` is not a constant expression
+#else
+
 BOOST_STATIC_ASSERT( en2.failed() );
 BOOST_STATIC_ASSERT( en2 );
 BOOST_STATIC_ASSERT( !!en2 );

+#endif
+
 constexpr error_condition en3;

 BOOST_STATIC_ASSERT( !en3.failed() );
--- a/test/failed_test.cpp
+++ b/test/failed_test.cpp
@@ -120,18 +120,30 @@ template<class Ec> void test()
        ec.assign( 0, generic_category() );
        TEST_NOT_FAILED( ec );
    }
+}

-    {
-        Ec ec( 0, http_category() );
-        TEST_FAILED( ec );
+template<class Ec> void test2()
+{
+    Ec ec( 0, http_category() );
+    TEST_FAILED( ec );

-        ec.assign( 200, http_category() );
-        TEST_NOT_FAILED( ec );
+    ec.assign( 200, http_category() );
+    TEST_NOT_FAILED( ec );

-        ec = Ec( 404, http_category() );
-        TEST_FAILED( ec );
-    }
+    ec = Ec( 404, http_category() );
+    TEST_FAILED( ec );
+}

+template<class Ec> void test3()
+{
+    Ec ec( 0, http_category() );
+    BOOST_TEST( ec.failed() );
+
+    ec.assign( 200, http_category() );
+    BOOST_TEST( !ec.failed() );
+
+    ec = Ec( 404, http_category() );
+    BOOST_TEST( ec.failed() );
 }

 int main()
@@ -147,7 +159,9 @@ int main()
    BOOST_TEST( http_category().failed( 404 ) );

    test<error_code>();
+    test2<error_code>();
    test<error_condition>();
+    test3<error_condition>();

    {
        error_condition ec( errc::success );
--- a/test/generic_category_test2.cpp
+++ b/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();
+}
--- a/test/generic_category_test3.cpp
+++ b/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();
+}
--- a/test/is_error_code_enum_test.cpp
+++ b/test/is_error_code_enum_test.cpp
@@ -0,0 +1,41 @@
+// Copyright 2020 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/is_error_code_enum.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+enum error
+{
+    success = 0,
+    e1,
+    e2,
+    e3
+};
+
+namespace boost
+{
+namespace system
+{
+
+template<> struct is_error_code_enum< ::error >
+{
+    static const bool value = true;
+};
+
+}
+}
+
+boost::system::error_code make_error_code( ::error e );
+
+enum not_error
+{
+};
+
+int main()
+{
+    BOOST_TEST( boost::system::is_error_code_enum< ::error >::value );
+    BOOST_TEST( !boost::system::is_error_code_enum< ::not_error >::value );
+
+    return boost::report_errors();
+}
--- a/test/is_error_condition_enum_test.cpp
+++ b/test/is_error_condition_enum_test.cpp
@@ -0,0 +1,40 @@
+// Copyright 2020 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/is_error_condition_enum.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+enum condition
+{
+    c1 = 1,
+    c2,
+    c3
+};
+
+namespace boost
+{
+namespace system
+{
+
+template<> struct is_error_condition_enum< ::condition >
+{
+    static const bool value = true;
+};
+
+}
+}
+
+boost::system::error_condition make_error_condition( ::condition e );
+
+enum not_condition
+{
+};
+
+int main()
+{
+    BOOST_TEST( boost::system::is_error_condition_enum< ::condition >::value );
+    BOOST_TEST( !boost::system::is_error_condition_enum< ::not_condition >::value );
+
+    return boost::report_errors();
+}
--- a/test/linux_error_test.cpp
+++ b/test/linux_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/linux_error.hpp>
+#include <boost/config/pragma_message.hpp>
+
+#if !defined(__linux__)
+
+BOOST_PRAGMA_MESSAGE( "Skipping test, __linux__ is not defined" )
+int main() {}
+
+#else
+
+#include <boost/core/lightweight_test.hpp>
+
+int main()
+{
+    namespace sys = boost::system;
+
+    sys::error_code ec = sys::linux_error::dot_dot_error;
+
+    BOOST_TEST_EQ( ec, sys::linux_error::dot_dot_error );
+    BOOST_TEST_EQ( ec, sys::error_code( EDOTDOT, sys::system_category() ) );
+
+    return boost::report_errors();
+}
+
+#endif
--- a/test/quick.cpp
+++ b/test/quick.cpp
@@ -1,15 +1,10 @@
-
-// Copyright 2017 Peter Dimov.
-//
+// Copyright 2017, 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
+// https://www.boost.org/LICENSE_1_0.txt

 // See library home page at http://www.boost.org/libs/system

-#include <boost/system/system_error.hpp>
-#include <boost/system/error_code.hpp>
+#include <boost/system.hpp>
 #include <boost/core/lightweight_test.hpp>
 #include <cerrno>

@@ -33,6 +28,12 @@ int main()

    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 );
--- a/test/system_category_test2.cpp
+++ b/test/system_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/system_category.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+// Tests whether system_category() is functional when only
+// system_category.hpp is included
+
+namespace sys = boost::system;
+
+int main()
+{
+    sys::error_category const & cat = sys::system_category();
+
+    BOOST_TEST_CSTR_EQ( cat.name(), "system" );
+
+    return boost::report_errors();
+}
--- a/test/system_category_test3.cpp
+++ b/test/system_category_test3.cpp
@@ -0,0 +1,41 @@
+// Copyright 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/system_category.hpp>
+#include <boost/system/generic_category.hpp>
+#include <boost/system/error_condition.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+namespace sys = boost::system;
+
+int main()
+{
+    sys::error_category const & cat = sys::system_category();
+
+    // name
+    BOOST_TEST_CSTR_EQ( cat.name(), "system" );
+
+    // default_error_condition
+    BOOST_TEST( cat.default_error_condition( 0 ) == sys::error_condition() );
+
+    // No longer holds; returns a generic condition
+    // BOOST_TEST( cat.default_error_condition( -1 ) == sys::error_condition( -1, cat ) );
+
+#if defined(BOOST_WINDOWS_API)
+
+    BOOST_TEST( cat.default_error_condition( 5 ) == sys::error_condition( EACCES, sys::generic_category() ) );
+
+#else
+
+    BOOST_TEST( cat.default_error_condition( EACCES ) == sys::error_condition( EACCES, sys::generic_category() ) );
+
+#endif
+
+    // failed
+    BOOST_TEST( !cat.failed( 0 ) );
+    BOOST_TEST( cat.failed( 5 ) );
+    BOOST_TEST( cat.failed( -1 ) );
+
+    return boost::report_errors();
+}
--- a/test/windows_error_test.cpp
+++ b/test/windows_error_test.cpp
@@ -0,0 +1,31 @@
+// Copyright 2020 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/windows_error.hpp>
+#include <boost/config/pragma_message.hpp>
+
+#if !defined(BOOST_WINDOWS_API)
+
+BOOST_PRAGMA_MESSAGE( "Skipping test, BOOST_WINDOWS_API is not defined" )
+int main() {}
+
+#else
+
+#include <boost/core/lightweight_test.hpp>
+#include <windows.h>
+
+int main()
+{
+    namespace sys = boost::system;
+
+    sys::error_code ec = sys::windows_error::invalid_function;
+
+    BOOST_TEST_EQ( ec, sys::windows_error::invalid_function );
+    BOOST_TEST_EQ( ec, sys::error_code( ERROR_INVALID_FUNCTION, sys::system_category() ) );
+    BOOST_TEST( ec == make_error_condition( sys::errc::function_not_supported ) );
+
+    return boost::report_errors();
+}
+
+#endif
Author	SHA1	Message	Date
Peter Dimov	1caaacff57	Split reference into headers	2021-06-13 06:58:48 +03:00
Peter Dimov	75d5287558	Update copyright	2021-06-13 05:59:04 +03:00
Peter Dimov	25eaf0fdae	Document comparisons as inline friends; use value() and category() instead of val_ and cat_; add subheadings	2021-06-13 05:58:16 +03:00
Peter Dimov	f43293f451	Increase ToC levels	2021-06-13 05:24:30 +03:00
Peter Dimov	88f7c2bf53	Revert "Update documentation" This reverts commit `8962c9101a`.	2021-06-13 04:47:19 +03:00
Peter Dimov	723daf5d57	Update changelog	2021-06-13 04:39:39 +03:00
Peter Dimov	3d4c31c213	Update test/Jamfile	2021-06-13 01:13:48 +03:00
Peter Dimov	c069ae048f	Update Travis to use undefined-sanitizer; disable failed_constexpr_test	2021-06-13 01:08:54 +03:00
Peter Dimov	28e1b919ac	Disable failing test	2021-06-12 22:36:12 +03:00
Peter Dimov	b20191f8d7	Disable failing tests on g++-7/c++17	2021-06-12 22:20:38 +03:00
Peter Dimov	d019c1cdae	Remove detail/is_generic_value.hpp	2021-06-12 22:01:16 +03:00
Peter Dimov	ff77d4c094	Do not call generic_category() in system_error_category	2021-06-12 21:59:22 +03:00
Peter Dimov	a21a3050a5	Use nullptr for &generic_category() in error_condition	2021-06-12 21:51:51 +03:00
Peter Dimov	08d62ac444	Restore Sun workaround	2021-06-12 05:42:03 +03:00
Peter Dimov	45e9dfeba9	Declare operator std::error_category as BOOST_SYMBOL_VISIBLE	2021-06-12 05:12:58 +03:00
Peter Dimov	7d9eb384c6	Make error_category comparisons inline friends, to avoid clang 'member call on mutable' constexpr errors	2021-06-12 04:52:21 +03:00
Peter Dimov	04bfb05b19	Improve the implementation of the std::category conversion	2021-06-12 04:29:13 +03:00
Peter Dimov	a650f5d676	Remove cmake_install_test dependency on Boost::core	2021-06-12 00:18:26 +03:00
Peter Dimov	6ab5fd9dac	Update ci.yml	2021-06-11 22:15:46 +03:00
Peter Dimov	ed14d74323	Update .travis.yml	2021-06-11 22:12:35 +03:00
Peter Dimov	ff9bca96e3	Add boost/system.hpp	2021-06-11 21:15:17 +03:00
Peter Dimov	8560290b71	Merge pull request #67 from Lastique/feature/add_win32_error_not_supported Add support for Windows error code ERROR_NOT_SUPPORTED	2021-05-29 03:36:51 +03:00
Peter Dimov	8b41ff22a6	Update ci.yml	2021-05-29 02:41:45 +03:00
Peter Dimov	79f9a297cd	Update ci.yml	2021-05-29 01:15:51 +03:00
Andrey Semashev	344ea58a77	Added support for Windows error code ERROR_NOT_SUPPORTED. The error code description reads as "The request is not supported," which is close to POSIX ENOTSUP "Not supported" and matches MSVC standard library implementation.	2021-05-29 00:55:40 +03:00
Peter Dimov	5eae4824ab	Update .github/workflows	2021-04-19 21:29:14 +03:00
Peter Dimov	f502e6cda4	Update .github/workflows	2021-04-19 20:30:50 +03:00
Peter Dimov	69bc20fb15	Merge pull request #66 from vahtis/vahtis-patch-1 Define BOOST_SYSTEM_DEPRECATED for Oracle Developer Studio	2021-03-22 17:23:49 +02:00
vahtis	fbf7f4a417	Define BOOST_SYSTEM_DEPRECATED for Oracle Developer Studio Added Oracle Developer Studio specific define.	2021-03-22 15:38:27 +02:00
Peter Dimov	689e09e86f	Merge pull request #65 from eldiener/develop [skip ci] Add "cxxstd" json field	2021-01-21 18:58:57 +02:00
Edward Diener	b92035d4d2	[skip ci] Add "cxxstd" json field. The "cxxstd" json field is being added to each Boost library's meta json information for libraries in order to specify the minumum C++ standard compilation level. The value of this field matches one of the values for 'cxxstd' in Boost.Build. The purpose of doing this is to provide information for the Boost website documentation for each library which will specify the minimum C++ standard compilation that an end-user must employ in order to use the particular library. This will aid end-users who want to know if they can successfully use a Boost library based on their C++ compiler's compilation level, without having to search the library's documentation to find this out.	2021-01-21 11:11:01 -05:00
Peter Dimov	63a32cea9a	Remove deprecation message from windows_error.hpp (closes #57 )	2021-01-02 22:16:39 +02:00
Peter Dimov	3e2cb8975f	Update .travis.yml	2021-01-02 16:19:54 +02:00
Peter Dimov	4e7c88779b	Merge branch 'patch-1' of https://github.com/tanzislam/system into feature/pr-56	2020-12-24 02:11:38 +02:00
Peter Dimov	3ee8200e75	Add .github/workflows	2020-12-24 02:10:50 +02:00
Tanzinul Islam	516484a821	Define BOOST_SYSTEM_DEPRECATED for other compilers Currently compilation fails with Oracle Developer Studio 12.6, for example: $ ./b2 toolset=sun threading=multi variant=debug link=static cxxflags=-std=c++11 --with-system ... "./boost/system/detail/error_condition.hpp", line 96: Error: BOOST_SYSTEM_DEPRECATED is not defined. "./boost/system/detail/error_condition.hpp", line 96: Error: No direct declarator preceding ""this function is slated for removal"". "./boost/system/detail/error_condition.hpp", line 96: Error: No direct declarator preceding "(".	2020-12-23 23:57:18 +00:00
Peter Dimov	39bd8ba98f	Use address-model=32 for msvc-9.0, 10.0, 11.0	2020-10-06 13:29:14 +03:00
Peter Dimov	f1c0a52426	Fix typo	2020-10-06 04:44:07 +03:00
Peter Dimov	8962c9101a	Update documentation	2020-10-06 04:26:02 +03:00
Peter Dimov	329e72fb92	Mark error_condition::failed, error_condition::message as deprecated; revert op bool	2020-10-06 04:03:13 +03:00
Peter Dimov	6758690d2f	Add BOOST_SYSTEM_DEPRECATED; mark deprecated categories	2020-10-06 03:42:00 +03:00
Peter Dimov	8f32183b63	Mark platform-specific error headers as deprecated; split tests	2020-10-06 03:21:38 +03:00
Peter Dimov	99db03ee96	Remove tab	2020-09-04 17:02:14 +03:00
Peter Dimov	2e1ae5bc7a	Remove unnecessary includes	2020-08-28 15:20:13 +03:00
Peter Dimov	7236be0c58	Add errc_test2	2020-08-28 02:00:20 +03:00
Peter Dimov	776834b723	Rename std_interoperability.hpp to to_std_category.hpp, make it self-contained	2020-08-28 01:03:15 +03:00
Peter Dimov	7d6da0ad91	Add tests for failed()	2020-08-27 17:49:20 +03:00
Peter Dimov	999cf08bf5	Add system_category_test3	2020-08-27 17:47:06 +03:00
Peter Dimov	96418c1531	Add generic_category_test3	2020-08-27 17:41:33 +03:00
Peter Dimov	717867cf4e	Remove unnecessary includes	2020-08-27 17:40:27 +03:00
Peter Dimov	7e2a02b16d	Rename system_category_posix.hpp to is_generic_value.hpp	2020-08-27 17:31:52 +03:00
Peter Dimov	b7e3be2798	Add system_category.hpp	2020-08-27 17:22:24 +03:00
Peter Dimov	e919caa2b4	Add generic_category.hpp	2020-08-27 16:35:32 +03:00
Peter Dimov	b951517625	Move system_category implementation to system_category_impl.hpp	2020-08-27 16:25:34 +03:00
Peter Dimov	ff18f28684	Move make_ functions for errc to errc.hpp	2020-08-27 16:15:10 +03:00
Peter Dimov	96321beb88	Add error_condition.hpp	2020-08-27 15:45:07 +03:00
Peter Dimov	313982fa52	Move interoperability support to error_category_impl.hpp	2020-08-27 15:14:17 +03:00
Peter Dimov	cc2b081a9e	Add boost/system/error_category.hpp	2020-08-27 03:38:30 +03:00
Peter Dimov	a93572ab16	Extract error_category implementation into its own header	2020-08-27 03:23:00 +03:00
Peter Dimov	cc49bc4457	Extract `throws` into its own header	2020-08-27 03:06:14 +03:00
Peter Dimov	6bc7edbfa8	Rename generic_category_impl.hpp to generic_category_message.hpp	2020-08-27 02:59:30 +03:00
Peter Dimov	c345b86b0a	Restore generic_category_impl.hpp; functions are needed by system_category	2020-08-27 02:56:18 +03:00
Peter Dimov	13bac420ab	Move op!= for error_condition	2020-08-27 02:26:32 +03:00
Peter Dimov	abc94afdb2	Extract error_code into its own header	2020-08-27 02:23:50 +03:00
Peter Dimov	867ac5b446	Move generic_category(), system_category() to their respective headers; extract error_condition into its own header	2020-08-27 02:07:22 +03:00
Peter Dimov	d50db54c44	Move failed_impl into error_category.hpp	2020-08-27 01:36:44 +03:00
Peter Dimov	72ea1ef846	Extract enable_if into its own header	2020-08-27 01:21:56 +03:00
Peter Dimov	d581eb203e	Extract system_error_category into its own header	2020-08-27 01:15:28 +03:00
Peter Dimov	3047581c75	Remove generic_category_impl.hpp	2020-08-27 01:06:54 +03:00
Peter Dimov	ddd679e6d7	Extract generic_error_category into its own header	2020-08-27 01:06:07 +03:00
Peter Dimov	4ec6c99148	Rename detail/generic_category.hpp	2020-08-27 00:51:03 +03:00
Peter Dimov	7b56fd9acf	Extract error_category into its own header	2020-08-27 00:47:48 +03:00
Peter Dimov	b6a447cdde	Extract errc into its own header	2020-08-27 00:31:45 +03:00
Peter Dimov	83019b5822	Extract is_error_code_enum, is_error_condition_enum into their own headers	2020-08-26 22:46:27 +03:00