Update appveyor.yml

Update CMakeLists.txt
2025-12-25 08:18:05 +01:00 · 2023-01-12 20:38:54 +02:00 · 2023-01-12 15:18:11 +02:00 · 2023-01-12 10:37:55 +02:00 · 2023-01-12 10:36:56 +02:00 · 2023-01-12 05:45:30 +02:00
43 changed files with 2774 additions and 302 deletions
--- a/.drone.jsonnet
+++ b/.drone.jsonnet
@@ -0,0 +1,319 @@
+# Copyright 2022 Peter Dimov
+# Distributed under the Boost Software License, Version 1.0.
+# https://www.boost.org/LICENSE_1_0.txt
+
+local library = "system";
+
+local triggers =
+{
+    branch: [ "master", "develop", "feature/*" ]
+};
+
+local ubsan = { UBSAN: '1', UBSAN_OPTIONS: 'print_stacktrace=1' };
+local asan = { ASAN: '1' };
+
+local linux_pipeline(name, image, environment, packages = "", sources = [], arch = "amd64") =
+{
+    name: name,
+    kind: "pipeline",
+    type: "docker",
+    trigger: triggers,
+    platform:
+    {
+        os: "linux",
+        arch: arch
+    },
+    steps:
+    [
+        {
+            name: "everything",
+            image: image,
+            environment: environment,
+            commands:
+            [
+                'set -e',
+                'wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | apt-key add -',
+            ] +
+            (if sources != [] then [ ('apt-add-repository "' + source + '"') for source in sources ] else []) +
+            (if packages != "" then [ 'apt-get update', 'apt-get -y install ' + packages ] else []) +
+            [
+                'export LIBRARY=' + library,
+                './.drone/drone.sh',
+            ]
+        }
+    ]
+};
+
+local macos_pipeline(name, environment, xcode_version = "12.2", osx_version = "catalina", arch = "amd64") =
+{
+    name: name,
+    kind: "pipeline",
+    type: "exec",
+    trigger: triggers,
+    platform: {
+        "os": "darwin",
+        "arch": arch
+    },
+    node: {
+        "os": osx_version
+    },
+    steps: [
+        {
+            name: "everything",
+            environment: environment + { "DEVELOPER_DIR": "/Applications/Xcode-" + xcode_version + ".app/Contents/Developer" },
+            commands:
+            [
+                'export LIBRARY=' + library,
+                './.drone/drone.sh',
+            ]
+        }
+    ]
+};
+
+local windows_pipeline(name, image, environment, arch = "amd64") =
+{
+    name: name,
+    kind: "pipeline",
+    type: "docker",
+    trigger: triggers,
+    platform:
+    {
+        os: "windows",
+        arch: arch
+    },
+    "steps":
+    [
+        {
+            name: "everything",
+            image: image,
+            environment: environment,
+            commands:
+            [
+                'cmd /C .drone\\\\drone.bat ' + library,
+            ]
+        }
+    ]
+};
+
+[
+    linux_pipeline(
+        "Linux 14.04 GCC 4.4",
+        "cppalliance/droneubuntu1404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-4.4', CXXSTD: '98,0x' },
+        "g++-4.4",
+        [ "ppa:ubuntu-toolchain-r/test" ],
+    ),
+
+    linux_pipeline(
+        "Linux 14.04 GCC 4.6",
+        "cppalliance/droneubuntu1404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-4.6', CXXSTD: '98,0x' },
+        "g++-4.6",
+        [ "ppa:ubuntu-toolchain-r/test" ],
+    ),
+
+    linux_pipeline(
+        "Linux 14.04 GCC 4.7",
+        "cppalliance/droneubuntu1404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-4.7', CXXSTD: '98,0x' },
+        "g++-4.7",
+        [ "ppa:ubuntu-toolchain-r/test" ],
+    ),
+
+    linux_pipeline(
+        "Linux 14.04 GCC 4.8*",
+        "cppalliance/droneubuntu1404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11' },
+    ),
+
+    linux_pipeline(
+        "Linux 14.04 GCC 4.9",
+        "cppalliance/droneubuntu1404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-4.9', CXXSTD: '03,11' },
+        "g++-4.9",
+        [ "ppa:ubuntu-toolchain-r/test" ],
+    ),
+
+    linux_pipeline(
+        "Linux 16.04 GCC 5*",
+        "cppalliance/droneubuntu1604:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14' },
+    ),
+
+    linux_pipeline(
+        "Linux 18.04 GCC 6",
+        "cppalliance/droneubuntu1804:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-6', CXXSTD: '03,11,14' },
+        "g++-6",
+    ),
+
+    linux_pipeline(
+        "Linux 18.04 GCC 7* 32/64",
+        "cppalliance/droneubuntu1804:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17', ADDRMD: '32,64' },
+    ),
+
+    linux_pipeline(
+        "Linux 18.04 GCC 8",
+        "cppalliance/droneubuntu1804:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-8', CXXSTD: '03,11,14,17' },
+        "g++-8",
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 GCC 9* 32",
+        "cppalliance/droneubuntu2004:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17,2a', ADDRMD: '32' },
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 GCC 9* 64",
+        "cppalliance/droneubuntu2004:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17,2a', ADDRMD: '64' },
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 GCC 9* ARM64",
+        "cppalliance/droneubuntu2004:multiarch",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17,2a' },
+        arch="arm64",
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 GCC 9* S390x",
+        "cppalliance/droneubuntu2004:multiarch",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17,2a' },
+        arch="s390x",
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 GCC 10 32",
+        "cppalliance/droneubuntu2004:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-10', CXXSTD: '03,11,14,17,20', ADDRMD: '32' },
+        "g++-10-multilib",
+    ),
+
+    linux_pipeline(
+        "Linux 20.04 GCC 10 64",
+        "cppalliance/droneubuntu2004:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-10', CXXSTD: '03,11,14,17,20', ADDRMD: '64' },
+        "g++-10-multilib",
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 GCC 11* 32",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17,2a', ADDRMD: '32' },
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 GCC 11* 64",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++', CXXSTD: '03,11,14,17,2a', ADDRMD: '64' },
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 GCC 12 32 ASAN",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '32' } + asan,
+        "g++-12-multilib",
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 GCC 12 64 ASAN",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '03,11,14,17,20,2b', ADDRMD: '64' } + asan,
+        "g++-12-multilib",
+    ),
+
+    linux_pipeline(
+        "Linux 16.04 Clang 3.5",
+        "cppalliance/droneubuntu1604:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-3.5', CXXSTD: '03,11' },
+        "clang-3.5",
+    ),
+
+    linux_pipeline(
+        "Linux 16.04 Clang 3.6",
+        "cppalliance/droneubuntu1604:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-3.6', CXXSTD: '03,11,14' },
+        "clang-3.6",
+    ),
+
+    linux_pipeline(
+        "Linux 16.04 Clang 3.7",
+        "cppalliance/droneubuntu1604:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-3.7', CXXSTD: '03,11,14' },
+        "clang-3.7",
+    ),
+
+    linux_pipeline(
+        "Linux 16.04 Clang 3.8",
+        "cppalliance/droneubuntu1604:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-3.8', CXXSTD: '03,11,14' },
+        "clang-3.8",
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 Clang 13",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-13', CXXSTD: '03,11,14,17,20' },
+        "clang-13",
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 Clang 14 UBSAN",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-14', CXXSTD: '03,11,14,17,20' } + ubsan,
+        "clang-14",
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 Clang 14 ASAN",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-14', CXXSTD: '03,11,14,17,20' } + asan,
+        "clang-14",
+    ),
+
+    linux_pipeline(
+        "Linux 22.04 Clang 15",
+        "cppalliance/droneubuntu2204:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-15', CXXSTD: '03,11,14,17,20,2b' },
+        "clang-15",
+        ["deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-15 main"],
+    ),
+
+    macos_pipeline(
+        "MacOS 10.15 Xcode 12.2 UBSAN",
+        { TOOLSET: 'clang', COMPILER: 'clang++', CXXSTD: '03,11,14,1z' } + ubsan,
+    ),
+
+    macos_pipeline(
+        "MacOS 10.15 Xcode 12.2 ASAN",
+        { TOOLSET: 'clang', COMPILER: 'clang++', CXXSTD: '03,11,14,1z' } + asan,
+    ),
+
+    windows_pipeline(
+        "Windows VS2015 msvc-14.0",
+        "cppalliance/dronevs2015",
+        { TOOLSET: 'msvc-14.0', CXXSTD: '14,latest' },
+    ),
+
+    windows_pipeline(
+        "Windows VS2017 msvc-14.1",
+        "cppalliance/dronevs2017",
+        { TOOLSET: 'msvc-14.1', CXXSTD: '14,17,latest' },
+    ),
+
+    windows_pipeline(
+        "Windows VS2019 msvc-14.2",
+        "cppalliance/dronevs2019",
+        { TOOLSET: 'msvc-14.2', CXXSTD: '14,17,20,latest' },
+    ),
+
+    windows_pipeline(
+        "Windows VS2022 msvc-14.3",
+        "cppalliance/dronevs2022:1",
+        { TOOLSET: 'msvc-14.3', CXXSTD: '14,17,20,latest' },
+    ),
+]
--- a/.drone.star
+++ b/.drone.star
@@ -1,32 +0,0 @@
-# Copyright 2020 Rene Rivera
-# Copyright 2022 Peter Dimov
-# Distributed under the Boost Software License, Version 1.0.
-# https://www.boost.org/LICENSE_1_0.txt
-
-globalenv={ 'UBSAN_OPTIONS': 'print_stacktrace=1' }
-
-def main(ctx):
-  return [
-  linux_cxx("GCC 4.4 14.04", "", packages="g++-4.4", buildscript="drone", image="cppalliance/droneubuntu1404:1", environment={'TOOLSET': 'gcc', 'COMPILER': 'g++-4.4', 'CXXSTD': '98,0x'}, globalenv=globalenv),
-  linux_cxx("GCC 4.6 14.04", "", packages="g++-4.6", buildscript="drone", image="cppalliance/droneubuntu1404:1", environment={'TOOLSET': 'gcc', 'COMPILER': 'g++-4.6', 'CXXSTD': '03,0x'}, globalenv=globalenv),
-  linux_cxx("GCC 4.8* 14.04", "", packages="g++-multilib", buildscript="drone", image="cppalliance/droneubuntu1404:1", environment={'TOOLSET': 'gcc', 'COMPILER': 'g++', 'CXXSTD': '03,11', 'ADDRMD': '32,64'}, globalenv=globalenv),
-  linux_cxx("GCC 4.9 14.04", "", packages="g++-4.9", buildscript="drone", image="cppalliance/droneubuntu1404:1", environment={'TOOLSET': 'gcc', 'COMPILER': 'g++-4.9', 'CXXSTD': '03,11'}, globalenv=globalenv),
-  linux_cxx("GCC 5* 16.04", "", packages="g++-multilib", buildscript="drone", image="cppalliance/droneubuntu1604:1", environment={'TOOLSET': 'gcc', 'COMPILER': 'g++', 'CXXSTD': '03,11,14', 'ADDRMD': '32,64'}, globalenv=globalenv),
-  linux_cxx("GCC 6 16.04", "", packages="g++-6", buildscript="drone", image="cppalliance/droneubuntu1604:1", environment={'TOOLSET': 'gcc', 'COMPILER': 'g++-6', 'CXXSTD': '03,11'}, globalenv=globalenv),
-  linux_cxx("GCC 7* 18.04", "", packages="g++-multilib", buildscript="drone", image="cppalliance/droneubuntu1804:1", environment={'TOOLSET': 'gcc', 'COMPILER': 'g++', 'CXXSTD': '03,11,14,1z', 'ADDRMD': '32,64'}, globalenv=globalenv),
-  #linux_cxx("GCC 8 18.04", "", packages="g++-8", buildscript="drone", image="cppalliance/droneubuntu1804:1", environment={'TOOLSET': 'gcc', 'COMPILER': 'g++-8', 'CXXSTD': '03,11,14,1z', 'ADDRMD': '32,64'}, globalenv=globalenv),
-  linux_cxx("GCC 9* 20.04", "", packages="g++-multilib", buildscript="drone", image="cppalliance/droneubuntu2004:1", environment={'TOOLSET': 'gcc', 'COMPILER': 'g++', 'CXXSTD': '03,11,14,17,2a', 'ADDRMD': '32,64'}, globalenv=globalenv),
-  linux_cxx("GCC 9* 20.04 UBSAN", "", packages="", buildscript="drone", image="cppalliance/droneubuntu2004:1", environment={'UBSAN': 1, 'TOOLSET': 'gcc', 'COMPILER': 'g++', 'CXXSTD': '03,11,14,17,2a', 'LINKFLAGS': '-fuse-ld=gold'}, globalenv=globalenv),
-  linux_cxx("GCC 9* 20.04 ARM64", "", packages="", buildscript="drone", image="cppalliance/droneubuntu2004:multiarch", arch="arm64", environment={'TOOLSET': 'gcc', 'COMPILER': 'g++', 'CXXSTD': '03,11,14,17,2a', 'ADDRMD': '32,64'}, globalenv=globalenv),
-  linux_cxx("Clang 3.4 14.04", "", packages="clang-3.4", buildscript="drone", image="cppalliance/droneubuntu1404:1", environment={'TOOLSET': 'clang', 'COMPILER': '/usr/bin/clang++', 'CXXSTD': '03,11'}, globalenv=globalenv),
-  linux_cxx("Clang 13 20.04 UBSAN", "", packages="clang-13", llvm_os="focal", llvm_ver="13", buildscript="drone", image="cppalliance/droneubuntu2004:1", environment={'UBSAN': '1', 'TOOLSET': 'clang', 'COMPILER': 'clang++-13', 'CXXSTD': '03,11,14,17,20'}, globalenv=globalenv),
-  linux_cxx("Clang 14 20.04 UBSAN", "", packages="clang-14", llvm_os="focal", llvm_ver="14", buildscript="drone", image="cppalliance/droneubuntu2004:1", environment={'UBSAN': '1', 'TOOLSET': 'clang', 'COMPILER': 'clang++-14', 'CXXSTD': '03,11,14,17,20'}, globalenv=globalenv),
-  osx_cxx("Xcode 12.2 UBSAN", "", packages="", buildtype="boost", buildscript="drone", xcode_version="12.2", environment={'UBSAN': '1', 'TOOLSET': 'clang', 'COMPILER': 'clang++', 'CXXSTD': '03,11,14,1z'}, globalenv=globalenv),
-  windows_cxx("msvc-14.0", "", image="cppalliance/dronevs2015", buildscript="drone", environment={"TOOLSET": "msvc-14.0", "CXXSTD": "14,latest"}, globalenv=globalenv),
-  windows_cxx("msvc-14.1", "", image="cppalliance/dronevs2017", buildscript="drone", environment={"TOOLSET": "msvc-14.1", "CXXSTD": "14,17,latest"}, globalenv=globalenv),
-  windows_cxx("msvc-14.2", "", image="cppalliance/dronevs2019", buildscript="drone", environment={"TOOLSET": "msvc-14.2", "CXXSTD": "14,17,20,latest"}, globalenv=globalenv),
-  windows_cxx("msvc-14.3", "", image="cppalliance/dronevs2022:1", buildscript="drone", environment={"TOOLSET": "msvc-14.3", "CXXSTD": "14,17,20,latest"}, globalenv=globalenv)
-    ]
-
-# from https://github.com/boostorg/boost-ci
-load("@boost_ci//ci/drone/:functions.star", "linux_cxx", "windows_cxx", "osx_cxx")
--- a/.drone/drone.bat
+++ b/.drone/drone.bat
@@ -1,24 +1,23 @@
+@REM Copyright 2022 Peter Dimov
+@REM Distributed under the Boost Software License, Version 1.0.
+@REM https://www.boost.org/LICENSE_1_0.txt
+
@ECHO ON

+set LIBRARY=%1
 set DRONE_BUILD_DIR=%CD%

-IF "%DRONE_BRANCH%" == "" (
-  for /F %%i in ("%GITHUB_REF%") do @set DRONE_BRANCH=%%~nxi
-)
-
-for /F %%i in ("%DRONE_REPO%") do @set SELF=%%~nxi
-
 set BOOST_BRANCH=develop
 if "%DRONE_BRANCH%" == "master" set BOOST_BRANCH=master
 cd ..
 git clone -b %BOOST_BRANCH% --depth 1 https://github.com/boostorg/boost.git boost-root
 cd boost-root
 git submodule update --init tools/boostdep
-xcopy /s /e /q %DRONE_BUILD_DIR% libs\%SELF%\
-python tools/boostdep/depinst/depinst.py %SELF%
+xcopy /s /e /q %DRONE_BUILD_DIR% libs\%LIBRARY%\
+python tools/boostdep/depinst/depinst.py %LIBRARY%
 cmd /c bootstrap
 b2 -d0 headers

 if not "%CXXSTD%" == "" set CXXSTD=cxxstd=%CXXSTD%
 if not "%ADDRMD%" == "" set ADDRMD=address-model=%ADDRMD%
-b2 -j3 libs/%SELF%/test toolset=%TOOLSET% %CXXSTD% %ADDRMD% variant=debug,release embed-manifest-via=linker
+b2 -j3 libs/%LIBRARY%/test toolset=%TOOLSET% %CXXSTD% %ADDRMD% variant=debug,release embed-manifest-via=linker
--- a/.drone/drone.sh
+++ b/.drone/drone.sh
@@ -1,31 +1,24 @@
 #!/bin/bash

-# Copyright 2020 Rene Rivera, Sam Darwin
+# Copyright 2022 Peter Dimov
 # Distributed under the Boost Software License, Version 1.0.
-# (See accompanying file LICENSE.txt or copy at http://boost.org/LICENSE_1_0.txt)
+# https://www.boost.org/LICENSE_1_0.txt

-set -e
-export TRAVIS_BUILD_DIR=$(pwd)
-export DRONE_BUILD_DIR=$(pwd)
-export TRAVIS_BRANCH=$DRONE_BRANCH
-export VCS_COMMIT_ID=$DRONE_COMMIT
-export GIT_COMMIT=$DRONE_COMMIT
-export REPO_NAME=$DRONE_REPO
-export PATH=~/.local/bin:/usr/local/bin:$PATH
+set -ex

-echo '==================================> INSTALL'
+DRONE_BUILD_DIR=$(pwd)
+
+BOOST_BRANCH=develop
+if [ "$DRONE_BRANCH" = "master" ]; then BOOST_BRANCH=master; fi

-BOOST_BRANCH=develop && [ "$TRAVIS_BRANCH" == "master" ] && BOOST_BRANCH=master || true
 cd ..
 git clone -b $BOOST_BRANCH --depth 1 https://github.com/boostorg/boost.git boost-root
 cd boost-root
 git submodule update --init tools/boostdep
-cp -r $TRAVIS_BUILD_DIR/* libs/system
-python tools/boostdep/depinst/depinst.py system
+cp -r $DRONE_BUILD_DIR/* libs/$LIBRARY
+python tools/boostdep/depinst/depinst.py $LIBRARY
 ./bootstrap.sh
 ./b2 -d0 headers

-echo '==================================> SCRIPT'
-
 echo "using $TOOLSET : : $COMPILER ;" > ~/user-config.jam
-./b2 -j3 libs/system/test toolset=$TOOLSET cxxstd=$CXXSTD variant=debug,release ${ADDRMD:+address-model=$ADDRMD} ${UBSAN:+cxxflags=-fsanitize=undefined cxxflags=-fno-sanitize-recover=undefined linkflags=-fsanitize=undefined define=UBSAN=1 debug-symbols=on} ${LINKFLAGS:+linkflags=$LINKFLAGS}
+./b2 -j3 libs/$LIBRARY/test toolset=$TOOLSET cxxstd=$CXXSTD variant=debug,release ${ADDRMD:+address-model=$ADDRMD} ${UBSAN:+undefined-sanitizer=norecover debug-symbols=on} ${ASAN:+address-sanitizer=norecover debug-symbols=on} ${LINKFLAGS:+linkflags=$LINKFLAGS}
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -19,22 +19,26 @@ jobs:
        include:
          - toolset: gcc-4.8
            cxxstd: "03,11"
-            os: ubuntu-18.04
+            os: ubuntu-latest
+            container: ubuntu:18.04
            install: g++-4.8
          - toolset: gcc-5
            cxxstd: "03,11,14,1z"
-            os: ubuntu-18.04
+            os: ubuntu-latest
+            container: ubuntu:18.04
            install: g++-5
          - toolset: gcc-6
            cxxstd: "03,11,14,1z"
-            os: ubuntu-18.04
+            os: ubuntu-latest
+            container: ubuntu:18.04
            install: g++-6
          - toolset: gcc-7
            cxxstd: "03,11,14,17"
-            os: ubuntu-18.04
+            os: ubuntu-latest
+            container: ubuntu:18.04
          - toolset: gcc-8
            cxxstd: "03,11,14,17,2a"
-            os: ubuntu-18.04
+            os: ubuntu-20.04
            install: g++-8
          - toolset: gcc-9
            cxxstd: "03,11,14,17,2a"
@@ -47,30 +51,37 @@ jobs:
            cxxstd: "03,11,14,17,2a"
            os: ubuntu-20.04
            install: g++-11
+          - toolset: gcc-12
+            cxxstd: "03,11,14,17,20,2b"
+            os: ubuntu-22.04
+            install: g++-12
          - toolset: clang
            compiler: clang++-3.9
            cxxstd: "03,11,14"
-            os: ubuntu-18.04
+            os: ubuntu-latest
+            container: ubuntu:18.04
            install: clang-3.9
          - toolset: clang
            compiler: clang++-4.0
            cxxstd: "03,11,14"
-            os: ubuntu-18.04
+            os: ubuntu-latest
+            container: ubuntu:18.04
            install: clang-4.0
          - toolset: clang
            compiler: clang++-5.0
            cxxstd: "03,11,14,1z"
-            os: ubuntu-18.04
+            os: ubuntu-latest
+            container: ubuntu:18.04
            install: clang-5.0
          - toolset: clang
            compiler: clang++-6.0
            cxxstd: "03,11,14,17"
-            os: ubuntu-18.04
+            os: ubuntu-20.04
            install: clang-6.0
          - toolset: clang
            compiler: clang++-7
            cxxstd: "03,11,14,17"
-            os: ubuntu-18.04
+            os: ubuntu-20.04
            install: clang-7
          - toolset: clang
            compiler: clang++-8
@@ -92,20 +103,44 @@ jobs:
            os: ubuntu-20.04
          - toolset: clang
            compiler: clang++-12
-            cxxstd: "03,11,14,17,2a"
+            cxxstd: "03,11,14,17,20"
            os: ubuntu-20.04
+          - toolset: clang
+            compiler: clang++-13
+            cxxstd: "03,11,14,17,20,2b"
+            os: ubuntu-22.04
+            install: clang-13
+          - toolset: clang
+            compiler: clang++-14
+            cxxstd: "03,11,14,17,20,2b"
+            os: ubuntu-22.04
+            install: clang-14
          - toolset: clang
            cxxstd: "03,11,14,17,2a"
-            os: macos-10.15
+            os: macos-11
+          - toolset: clang
+            cxxstd: "03,11,14,17,2a"
+            os: macos-12

    runs-on: ${{matrix.os}}
+    container: ${{matrix.container}}
+
+    defaults:
+      run:
+        shell: bash

    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
+
+      - name: Setup container environment
+        if: matrix.container
+        run: |
+          apt-get update
+          apt-get -y install sudo python git g++

      - name: Install packages
        if: matrix.install
-        run: sudo apt install ${{matrix.install}}
+        run: sudo apt-get -y install ${{matrix.install}}

      - name: Setup Boost
        run: |
@@ -148,10 +183,6 @@ jobs:
            cxxstd: "14"
            addrmd: 32,64
            os: windows-2019
-          - toolset: msvc-14.1
-            cxxstd: "14,17,latest"
-            addrmd: 32,64
-            os: windows-2016
          - toolset: msvc-14.2
            cxxstd: "14,17,20,latest"
            addrmd: 32,64
@@ -172,7 +203,7 @@ jobs:
    runs-on: ${{matrix.os}}

    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3

      - name: Setup Boost
        shell: cmd
@@ -207,18 +238,19 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - os: ubuntu-18.04
          - os: ubuntu-20.04
-          - os: macos-10.15
+          - os: ubuntu-22.04
+          - os: macos-11
+          - os: macos-12

    runs-on: ${{matrix.os}}

    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3

      - name: Install packages
        if: matrix.install
-        run: sudo apt install ${{matrix.install}}
+        run: sudo apt-get -y install ${{matrix.install}}

      - name: Setup Boost
        run: |
@@ -253,18 +285,19 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - os: ubuntu-18.04
          - os: ubuntu-20.04
-          - os: macos-10.15
+          - os: ubuntu-22.04
+          - os: macos-11
+          - os: macos-12

    runs-on: ${{matrix.os}}

    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3

      - name: Install packages
        if: matrix.install
-        run: sudo apt install ${{matrix.install}}
+        run: sudo apt-get -y install ${{matrix.install}}

      - name: Setup Boost
        run: |
@@ -309,18 +342,19 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - os: ubuntu-18.04
          - os: ubuntu-20.04
-          - os: macos-10.15
+          - os: ubuntu-22.04
+          - os: macos-11
+          - os: macos-12

    runs-on: ${{matrix.os}}

    steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3

      - name: Install packages
        if: matrix.install
-        run: sudo apt install ${{matrix.install}}
+        run: sudo apt-get -y install ${{matrix.install}}

      - name: Setup Boost
        run: |
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,7 +2,7 @@
 # Distributed under the Boost Software License, Version 1.0.
 # See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt

-cmake_minimum_required(VERSION 3.5...3.16)
+cmake_minimum_required(VERSION 3.5...3.20)

 project(boost_system VERSION "${BOOST_SUPERPROJECT_VERSION}" LANGUAGES CXX)

@@ -20,6 +20,15 @@ target_link_libraries(boost_system
    Boost::winapi
 )

+if(CMAKE_VERSION VERSION_GREATER 3.18 AND CMAKE_GENERATOR MATCHES "Visual Studio")
+
+  file(GLOB_RECURSE boost_system_IDEFILES CONFIGURE_DEPENDS include/*.hpp)
+  source_group(TREE ${PROJECT_SOURCE_DIR}/include FILES ${boost_system_IDEFILES} PREFIX "Header Files")
+  list(APPEND boost_system_IDEFILES extra/boost_system.natvis)
+  target_sources(boost_system PRIVATE ${boost_system_IDEFILES})
+
+endif()
+
 if(BUILD_TESTING)

  add_subdirectory(test)
--- a/README.md
+++ b/README.md
@@ -0,0 +1,25 @@
+# Boost.System
+
+The Boost.System library, part of [Boost C++ Libraries](https://boost.org),
+implements an extensible framework for error reporting in the form of an
+`error_code` class and supporting facilities.
+
+It has been proposed for the C++11 standard, has been accepted, and
+is now available as part of the standard library in the `<system_error>`
+header. However, the Boost implementation has continued to evolve and
+gain enhancements and additional functionality, such as support for
+attaching [source locations](https://www.boost.org/doc/libs/release/libs/assert/doc/html/assert.html#source_location_support)
+to `error_code`, and a `result<T>` class that can carry either a value
+or an error code.
+
+See [the documentation of System](http://boost.org/libs/system) for more
+information.
+
+Since `<system_error>` is a relatively undocumented portion of the C++
+standard library, the documentation of Boost.System may be useful to you
+even if you use the standard components.
+
+## License
+
+Distributed under the
+[Boost Software License, Version 1.0](http://boost.org/LICENSE_1_0.txt).
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -24,10 +24,6 @@ environment:
      TOOLSET: msvc-14.1
      CXXSTD: 14,17,latest
      ADDRMD: 32,64
-    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
-      TOOLSET: clang-win
-      CXXSTD: 14,17,latest
-      ADDRMD: 32,64
    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
      ADDPATH: C:\cygwin\bin;
      TOOLSET: gcc
@@ -44,6 +40,12 @@ environment:
      ADDPATH: C:\mingw-w64\x86_64-6.3.0-posix-seh-rt_v5-rev1\mingw64\bin;
      TOOLSET: gcc
      CXXSTD: 03,11,14,1z
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      CMAKE: 1
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
+      CMAKE_SUBDIR: 1
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+      CMAKE_INSTALL: 1

 install:
  - set BOOST_BRANCH=develop
@@ -63,4 +65,27 @@ test_script:
  - PATH=%ADDPATH%%PATH%
  - if not "%CXXSTD%" == "" set CXXSTD=cxxstd=%CXXSTD%
  - if not "%ADDRMD%" == "" set ADDRMD=address-model=%ADDRMD%
-  - b2 -j3 libs/system/test toolset=%TOOLSET% %CXXSTD% %ADDRMD% variant=debug,release embed-manifest-via=linker
+  - if "%CMAKE%%CMAKE_SUBDIR%%CMAKE_INSTALL%" == ""  b2 -j3 libs/system/test toolset=%TOOLSET% %CXXSTD% %ADDRMD% variant=debug,release embed-manifest-via=linker
+
+  - if not "%CMAKE%" == ""  mkdir __build__ && cd __build__
+  - if not "%CMAKE%" == ""  cmake -DBUILD_TESTING=ON -DBOOST_INCLUDE_LIBRARIES=system -DBoost_VERBOSE=ON ..
+  - if not "%CMAKE%" == ""  cmake --build . --target tests -j 3 --config Debug & ctest --output-on-failure --no-tests=error -j 3 -C Debug
+  - if not "%CMAKE%" == ""  cmake --build . --target tests -j 3 --config Release & ctest --output-on-failure --no-tests=error -j 3 -C Release
+  - if not "%CMAKE%" == ""  cmake --build . --target tests -j 3 --config MinSizeRel & ctest --output-on-failure --no-tests=error -j 3 -C MinSizeRel
+  - if not "%CMAKE%" == ""  cmake --build . --target tests -j 3 --config RelWithDebInfo & ctest --output-on-failure --no-tests=error -j 3 -C RelWithDebInfo
+
+  - if not "%CMAKE_SUBDIR%" == ""  cd libs/system/test/cmake_subdir_test && mkdir __build__ && cd __build__
+  - if not "%CMAKE_SUBDIR%" == ""  cmake ..
+  - if not "%CMAKE_SUBDIR%" == ""  cmake --build . --config Debug && cmake --build . --target check --config Debug
+  - if not "%CMAKE_SUBDIR%" == ""  cmake --build . --config Release && cmake --build . --target check --config Release
+  - if not "%CMAKE_SUBDIR%" == ""  cmake --build . --config MinSizeRel && cmake --build . --target check --config MinSizeRel
+  - if not "%CMAKE_SUBDIR%" == ""  cmake --build . --config RelWithDebInfo && cmake --build . --target check --config RelWithDebInfo
+
+  - if not "%CMAKE_INSTALL%" == ""  mkdir __build__ && cd __build__
+  - if not "%CMAKE_INSTALL%" == ""  cmake -DBOOST_INCLUDE_LIBRARIES=system -DCMAKE_INSTALL_PREFIX=C:/cmake-prefix ..
+  - if not "%CMAKE_INSTALL%" == ""  cmake --build . --target install --config Debug
+  - if not "%CMAKE_INSTALL%" == ""  cmake --build . --target install --config Release
+  - if not "%CMAKE_INSTALL%" == ""  cd ../libs/system/test/cmake_install_test && mkdir __build__ && cd __build__
+  - if not "%CMAKE_INSTALL%" == ""  cmake -DCMAKE_INSTALL_PREFIX=C:/cmake-prefix ..
+  - if not "%CMAKE_INSTALL%" == ""  cmake --build . --config Debug && cmake --build . --target check --config Debug
+  - if not "%CMAKE_INSTALL%" == ""  cmake --build . --config Release && cmake --build . --target check --config Release
--- a/doc/system/changes.adoc
+++ b/doc/system/changes.adoc
@@ -8,12 +8,32 @@ https://www.boost.org/LICENSE_1_0.txt
 # Revision History
 :idprefix:

+## Changes in Boost 1.81
+
+* The macro `BOOST_SYSTEM_DISABLE_THREADS` can now be defined to disable
+  the use of `<mutex>` (e.g. on single-threaded libstdc++).
+* Added `value_type`, `error_type`, `in_place_value`, `in_place_error`
+  to `result<>`.
+* Added `emplace` to `result<>`.
+
+## Changes in Boost 1.80
+
+* When an `error_code` is converted to `std::error_code` and then back
+  to `error_code`, the original is now restored, if possible.
+* Reworked the conversion from `error_category` to `std::error_category`
+  to avoid the one-time allocation that shows up on leak checkers.
+* Added a constructor that allows replacing the source location of an
+  `error_code`, and a corresponding `assign`.
+* Added a converting constructor to `result`.
+
 ## Changes in Boost 1.79

-* Added a `throw_exception_from_error` overload for `std::error_code`.
 * Added a `boost::source_location` parameter to `throw_exception_from_error`.
+* Added `throw_exception_from_error` overloads for `errc::errc_t`,
+  `std::error_code`, `std::errc`, `std::exception_ptr`.
 * `result<T>::value` now automatically supplies `BOOST_CURRENT_LOCATION` to
  `throw_exception_from_error` via a default argument.
+* Added an `errc::make_error_code` overload taking a source location.

 ## Changes in Boost 1.78

--- a/doc/system/reference.adoc
+++ b/doc/system/reference.adoc
@@ -29,6 +29,11 @@ When `BOOST_SYSTEM_USE_UTF8` is defined, on Windows the library returns
 UTF-8 messages using code page `CP_UTF8` instead of the default `CP_ACP`.
 This macro has no effect on POSIX.

+When `BOOST_SYSTEM_DISABLE_THREADS` is defined, the library assumes that
+the current platform doesn't support multiple threads and disables the use
+of the standard header `<mutex>`, eliminating the mutex locks. The single
+threaded `libstdc++` is one such platform.
+
 ## Deprecated Names

 In the process of adding Boost.System to the {cpp}11 standard library, the
@@ -185,9 +190,13 @@ namespace errc {
 template<> struct is_error_condition_enum<errc::errc_t>
  { static const bool value = true; };

-constexpr error_code make_error_code( errc::errc_t e ) noexcept;
 constexpr error_condition make_error_condition( errc::errc_t e ) noexcept;

+constexpr error_code make_error_code( errc::errc_t e ) noexcept;
+
+error_code make_error_code( errc::errc_t e,
+  boost::source_location const * loc ) noexcept;
+
 } // namespace system
 } // namespace boost
 ```
@@ -256,6 +265,38 @@ void my_api_function( boost::system::error_code& ec )
 }
 ```

+```
+constexpr error_code make_error_code( errc::errc_t e,
+  boost::source_location const * loc ) noexcept;
+```
+[none]
+* {blank}
+
+Returns: :: `error_code( e, generic_category(), loc )`.
+
+Same as the above overload, but takes a source location.
+* {blank}
+
+```
+void my_api_function( boost::system::error_code& ec )
+{
+    void* p = std::malloc( 16 );
+
+    if( p == 0 )
+    {
+        // return ENOMEM
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc =
+          BOOST_CURRENT_LOCATION;
+
+        ec = make_error_code( boost::system::errc::out_of_memory, &loc );
+        return;
+    }
+
+    // use p
+}
+```
+
 ## <boost/system/{zwsp}error_category.hpp>

 ### error_category
@@ -574,9 +615,8 @@ public:
    template<class ErrorCodeEnum>
      constexpr error_code( ErrorCodeEnum e ) noexcept;

-    template<class ErrorCodeEnum>
-      error_code( ErrorCodeEnum e, boost::source_location const * loc )
-        noexcept;
+    error_code( error_code const& ec,
+      boost::source_location const * loc ) noexcept;

    error_code( std::error_code const& ec ) noexcept;

@@ -590,9 +630,8 @@ public:
    template<class ErrorCodeEnum>
      constexpr error_code & operator=( ErrorCodeEnum e ) noexcept;

-    template<class ErrorCodeEnum>
-      void assign( ErrorCodeEnum e,
-        boost::source_location const * loc ) noexcept;
+    void assign( error_code const& ec,
+      boost::source_location const * loc ) noexcept;

    constexpr void clear() noexcept;

@@ -721,17 +760,17 @@ Ensures: :: `*this == make_error_code( e )`.
 Remarks: :: This constructor is only enabled when `is_error_code_enum<ErrorCodeEnum>::value` is `true`.

 ```
-template<class ErrorCodeEnum>
-  error_code( ErrorCodeEnum e, boost::source_location const * loc ) noexcept;
+error_code( error_code const& ec,
+  boost::source_location const * loc ) noexcept;
 ```
 [none]
 * {blank}
 +
-Requires: :: `loc` points to a valid `boost::source_location` object with static storage duration.
-Ensures: :: `*this == make_error_code( e )`.
-Remarks: :: This constructor is only enabled when `is_error_code_enum<ErrorCodeEnum>::value` is `true`.
-  When `make_error_code( e )` is not a default-constructed `error_code` and doesn't wrap a
-  `std::error_code`, `has_location()` is `true` and `&location()` is `loc`.
+Requires: :: `loc` points to a valid `boost::source_location` object with static storage duration, or is `nullptr`.
+Ensures: :: `*this == ec`.
+Remarks: :: When `ec` is a default-constructed `error_code` or wraps a `std::error_code`,
+  or when `loc` is `nullptr`, `*this` stores no location (`has_location()` is `false`).
+  Otherwise, `*this` stores `loc` (`has_location()` is `true` and `&location()` is `loc`.)

 ```
 error_code( std::error_code const & ec ) noexcept;
@@ -772,16 +811,13 @@ Ensures: :: `*this == make_error_code( e )`.
 Remarks: :: This operator is only enabled when `is_error_code_enum<ErrorCodeEnum>::value` is `true`.

 ```
-template<class ErrorCodeEnum>
-  void assign( ErrorCodeEnum e,
-    boost::source_location const * loc ) noexcept;
+void assign( error_code const& ec,
+  boost::source_location const * loc ) noexcept;
 ```
 [none]
 * {blank}
 +
-Requires: :: `loc` points to a valid `boost::source_location` object with static storage duration.
-Effects: :: `*this = error_code( e, loc )`.
-Remarks: :: This function is only enabled when `is_error_code_enum<ErrorCodeEnum>::value` is `true`.
+Effects: :: `*this = error_code( ec, loc )`.

 ```
 constexpr void clear() noexcept;
@@ -1460,6 +1496,15 @@ BOOST_NORETURN inline void throw_exception_from_error( error_code const & e,
 BOOST_NORETURN inline void throw_exception_from_error( std::error_code const & e,
  boost::source_location const & loc );

+BOOST_NORETURN inline void throw_exception_from_error( errc::errc_t const & e,
+  boost::source_location const & loc );
+
+BOOST_NORETURN inline void throw_exception_from_error( std::errc const & e,
+  boost::source_location const & loc );
+
+BOOST_NORETURN inline void throw_exception_from_error( std::exception_ptr & e,
+  boost::source_location const & loc );
+
 // in_place_*

 using in_place_value_t = /*unspecified*/;
@@ -1497,7 +1542,7 @@ BOOST_NORETURN inline void throw_exception_from_error( error_code const & e,
 * {blank}
 +
 Effects: ::
-  `boost::throw_exception( system_error( e ), loc )`.
+  `boost::throw_with_location( system_error( e ), loc )`.

 ```
 BOOST_NORETURN inline void throw_exception_from_error( std::error_code const & e,
@@ -1507,7 +1552,40 @@ BOOST_NORETURN inline void throw_exception_from_error( std::error_code const & e
 * {blank}
 +
 Effects: ::
-  `boost::throw_exception( std::system_error( e ), loc )`.
+  `boost::throw_with_location( std::system_error( e ), loc )`.
+
+```
+BOOST_NORETURN inline void throw_exception_from_error( errc::errc_t const & e,
+  boost::source_location const & loc );
+```
+[none]
+* {blank}
+
+Effects: ::
+  `boost::throw_with_location( system_error( make_error_code( e ) ), loc )`.
+
+```
+BOOST_NORETURN inline void throw_exception_from_error( std::errc const & e,
+  boost::source_location const & loc );
+```
+[none]
+* {blank}
+
+Effects: ::
+  `boost::throw_with_location( std::system_error( make_error_code( e ) ), loc )`.
+
+```
+BOOST_NORETURN inline void throw_exception_from_error( std::exception_ptr & e,
+  boost::source_location const & loc );
+```
+[none]
+* {blank}
+
+Effects: ::
+
+[disc]
+** If `e` isn't null, `std::rethrow_exception( e )`.
+** Otherwise, `boost::throw_with_location( std::bad_exception(), loc )`.

 ### result<T, E>

@@ -1522,6 +1600,12 @@ template<class T, class E = error_code> class result
 {
 public:

+    using value_type = T;
+    using error_type = E;
+
+    static constexpr in_place_value_t in_place_value{};
+    static constexpr in_place_error_t in_place_error{};
+
    // constructors

    constexpr result();
@@ -1535,6 +1619,12 @@ public:
    template<class... A>
      constexpr result( in_place_error_t, A&&... a );

+    template<class T2, class E2>
+      constexpr result( result<T2, E2> const& r2 );
+
+    template<class T2, class E2>
+      constexpr result( result<T2, E2>&& r2 );
+
    // queries

    constexpr bool has_value() const noexcept;
@@ -1569,6 +1659,11 @@ public:

    constexpr E error() const;

+    // emplace
+
+    template<class... A>
+      constexpr T& emplace( A&&... a );
+
    // swap

    constexpr void swap( result& r );
@@ -1643,6 +1738,30 @@ Ensures: ::
 Remarks: ::
  This constructor is only enabled when `std::is_constructible<E, A...>::value` is `true`.

+```
+template<class T2, class E2>
+  constexpr result( result<T2, E2> const& r2 );
+```
+[none]
+* {blank}
+
+Ensures: ::
+  If `r2.has_value()` is `true`, `*this` holds the value `T( *r2 )`, otherwise `*this` holds the value `E( r2.error() )`.
+Remarks: ::
+  This constructor is only enabled when `std::is_convertible<T2, T>::value && std::is_convertible<E2, E>::value` is `true`.
+
+```
+template<class T2, class E2>
+  constexpr result( result<T2, E2>&& r2 );
+```
+[none]
+* {blank}
+
+Ensures: ::
+  If `r2.has_value()` is `true`, `*this` holds the value `T( std::move( *r2 ) )`, otherwise `*this` holds the value `E( r2.error() )`.
+Remarks: ::
+  This constructor is only enabled when `std::is_convertible<T2, T>::value && std::is_convertible<E2, E>::value` is `true`.
+
 #### Queries

 ```
@@ -1740,6 +1859,20 @@ constexpr E error() const;
 Effects: ::
  If `*this` holds an error, returns it. Otherwise, returns `E()`.

+#### emplace
+
+```
+template<class... A>
+  constexpr T& emplace( A&&... a );
+```
+[none]
+* {blank}
+
+Ensures: ::
+  `*this` holds the value `T( std::forward<A>(a)... )`.
+Returns: ::
+  A reference to the contained value.
+
 #### swap

 ```
@@ -1808,6 +1941,12 @@ template<class E> class result<void, E>
 {
 public:

+    using value_type = void;
+    using error_type = E;
+
+    static constexpr in_place_value_t in_place_value{};
+    static constexpr in_place_error_t in_place_error{};
+
    // constructors

    constexpr result() noexcept;
@@ -1842,6 +1981,10 @@ public:

    constexpr E error() const;

+    // emplace
+
+    constexpr void emplace();
+
    // swap

    constexpr void swap( result& r );
@@ -1985,6 +2128,17 @@ constexpr E error() const;
 Effects: ::
  If `*this` holds an error, returns it. Otherwise, returns `E()`.

+#### emplace
+
+```
+constexpr void emplace();
+```
+[none]
+* {blank}
+
+Ensures: ::
+  `*this` holds an unspecified value.
+
 #### swap

 ```
--- a/extra/boost_system.natvis
+++ b/extra/boost_system.natvis
@@ -0,0 +1,53 @@
+<?xml version="1.0" encoding="utf-8"?>
+<AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+
+    <Type Name="boost::system::error_category">
+        <DisplayString Condition="id_ == 0xb2ab117a257edfd0">[generic]</DisplayString>
+        <DisplayString Condition="id_ == 0xb2ab117a257edfd1">[system]</DisplayString>
+        <DisplayString Condition="id_ == 0xb2ab117a257edfd2">[interop]</DisplayString>
+        <DisplayString Condition="id_ != 0">[{id_,x}]</DisplayString>
+        <DisplayString>@{((uintptr_t)this),x}</DisplayString>
+    </Type>
+
+    <Type Name="boost::system::error_code">
+        <DisplayString Condition="lc_flags_ == 0">{d1_.val_} [system] ✓</DisplayString>
+
+        <DisplayString Condition="lc_flags_ == 1 &amp;&amp; ((std::error_code*)d2_)->_Mycat->_Addr==1">{((std::error_code*)d2_)->_Myval} [std:future]</DisplayString>
+        <DisplayString Condition="lc_flags_ == 1 &amp;&amp; ((std::error_code*)d2_)->_Mycat->_Addr==3">{((std::error_code*)d2_)->_Myval} [std:generic]</DisplayString>
+        <DisplayString Condition="lc_flags_ == 1 &amp;&amp; ((std::error_code*)d2_)->_Mycat->_Addr==5">{((std::error_code*)d2_)->_Myval} [std:iostream]</DisplayString>
+        <DisplayString Condition="lc_flags_ == 1 &amp;&amp; ((std::error_code*)d2_)->_Mycat->_Addr==7">{((std::error_code*)d2_)->_Myval} [std:system]</DisplayString>
+        <DisplayString Condition="lc_flags_ == 1">{((std::error_code*)d2_)->_Myval} std@{((uintptr_t)((std::error_code*)d2_)->_Mycat),x}</DisplayString>
+
+        <DisplayString Condition="d1_.cat_->id_ == 0xb2ab117a257edfd0 &amp;&amp;
+            (lc_flags_ == 2 || (lc_flags_ &gt; 3 &amp;&amp; ( lc_flags_ % 2 == 0 )))">{d1_.val_} [generic] ✓</DisplayString>
+        <DisplayString Condition="d1_.cat_->id_ == 0xb2ab117a257edfd1 &amp;&amp;
+            (lc_flags_ == 2 || (lc_flags_ &gt; 3 &amp;&amp; ( lc_flags_ % 2 == 0 )))">{d1_.val_} [system] ✓</DisplayString>
+        <DisplayString Condition="d1_.cat_->id_ == 0xb2ab117a257edfd2 &amp;&amp;
+            (lc_flags_ == 2 || (lc_flags_ &gt; 3 &amp;&amp; ( lc_flags_ % 2 == 0 )))">{d1_.val_} [interop] ✓</DisplayString>
+        <DisplayString Condition="d1_.cat_->id_ != 0 &amp;&amp;
+            (lc_flags_ == 2 || (lc_flags_ &gt; 3 &amp;&amp; ( lc_flags_ % 2 == 0 )))">{d1_.val_} [{d1_.cat_->id_,x}] ✓</DisplayString>
+        <DisplayString Condition=
+            "lc_flags_ == 2 || (lc_flags_ &gt; 3 &amp;&amp; ( lc_flags_ % 2 == 0 ))">{d1_.val_} @{((uintptr_t)d1_.cat_),x} ✓</DisplayString>
+
+        <DisplayString Condition="d1_.cat_->id_ == 0xb2ab117a257edfd0 &amp;&amp;
+            (lc_flags_ &gt;= 3 &amp;&amp; ( lc_flags_ % 2 == 1 ))">{d1_.val_} [generic]</DisplayString>
+        <DisplayString Condition="d1_.cat_->id_ == 0xb2ab117a257edfd1 &amp;&amp;
+            (lc_flags_ &gt;= 3 &amp;&amp; ( lc_flags_ % 2 == 1 ))">{d1_.val_} [system]</DisplayString>
+        <DisplayString Condition="d1_.cat_->id_ == 0xb2ab117a257edfd2 &amp;&amp;
+            (lc_flags_ &gt;= 3 &amp;&amp; ( lc_flags_ % 2 == 1 ))">{d1_.val_} [interop]</DisplayString>
+        <DisplayString Condition="d1_.cat_->id_ != 0 &amp;&amp;
+            (lc_flags_ &gt;= 3 &amp;&amp; ( lc_flags_ % 2 == 1 ))">{d1_.val_} [{d1_.cat_->id_,x}]</DisplayString>
+        <DisplayString Condition=
+            "lc_flags_ &gt;= 3 &amp;&amp; ( lc_flags_ % 2 == 1 )">{d1_.val_} @{((uintptr_t)d1_.cat_),x}</DisplayString>
+
+        <Expand>
+            <Item Name="std::error_code" Condition="lc_flags_ == 1">(std::error_code*)d2_</Item>
+            <Item Name="[location]" Condition="lc_flags_ &gt; 3">*((boost::source_location*)(lc_flags_ &amp; ~1))</Item>
+        </Expand>
+    </Type>
+
+    <Type Name="boost::system::result&lt;*,*&gt;">
+        <DisplayString>{v_}</DisplayString>
+    </Type>
+
+</AutoVisualizer>
--- a/include/boost/system.hpp
+++ b/include/boost/system.hpp
@@ -9,8 +9,9 @@

 #include <boost/system/error_code.hpp>
 #include <boost/system/system_error.hpp>
+#include <boost/config.hpp>

-#if (__cplusplus >= 201103L) || (defined(_MSC_VER) && _MSC_VER >= 1900)
+#if (__cplusplus >= 201103L) && !(defined(BOOST_GCC) && BOOST_GCC < 40800) || (defined(_MSC_VER) && _MSC_VER >= 1900)
 # include <boost/system/result.hpp>
 #endif

--- a/include/boost/system/detail/config.hpp
+++ b/include/boost/system/detail/config.hpp
@@ -12,8 +12,14 @@
 #include <boost/config/workaround.hpp>

 // BOOST_SYSTEM_HAS_SYSTEM_ERROR
+//
+// The macro BOOST_SYSTEM_DISABLE_THREADS can be defined on configurations
+// that provide <system_error> and <atomic>, but not <mutex>, such as the
+// single-threaded libstdc++.
+//
+// https://github.com/boostorg/system/issues/92

-#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR) && !defined(BOOST_NO_CXX11_HDR_ATOMIC)
+#if !defined(BOOST_NO_CXX11_HDR_SYSTEM_ERROR) && !defined(BOOST_NO_CXX11_HDR_ATOMIC) && ( !defined(BOOST_NO_CXX11_HDR_MUTEX) || defined(BOOST_SYSTEM_DISABLE_THREADS) )
 # define BOOST_SYSTEM_HAS_SYSTEM_ERROR
 #endif

@@ -58,7 +64,9 @@

 // BOOST_SYSTEM_CLANG_6

-#if defined(__clang__) && (__clang_major__ < 7 || (defined(__APPLE__) && __clang_major__ < 11))
+// Android NDK r18b has Clang 7.0.2 that still needs the workaround
+// https://github.com/boostorg/system/issues/100
+#if defined(__clang__) && (__clang_major__ < 7 || (defined(__APPLE__) && __clang_major__ < 11) || (defined(__ANDROID__) && __clang_major__ == 7))
 # define BOOST_SYSTEM_CLANG_6
 #endif

--- a/include/boost/system/detail/error_category.hpp
+++ b/include/boost/system/detail/error_category.hpp
@@ -48,6 +48,11 @@ class std_category;
 #pragma GCC diagnostic ignored "-Wnon-virtual-dtor"
 #endif

+#if defined(BOOST_MSVC) && BOOST_MSVC < 1900
+#pragma warning(push)
+#pragma warning(disable: 4351) //  new behavior: elements of array will be default initialized
+#endif
+
 class BOOST_SYMBOL_VISIBLE error_category
 {
 private:
@@ -76,13 +81,21 @@ private:

    boost::ulong_long_type id_;

+    static std::size_t const stdcat_size_ = 4 * sizeof( void const* );
+
+    union
+    {
+        mutable unsigned char stdcat_[ stdcat_size_ ];
+        void const* stdcat_align_;
+    };
+
 #if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)

-    mutable std::atomic< boost::system::detail::std_category* > ps_;
+    mutable std::atomic< unsigned > sc_init_;

 #else

-    boost::system::detail::std_category* ps_;
+    unsigned sc_init_;

 #endif

@@ -103,11 +116,11 @@ protected:

 #endif

-    BOOST_SYSTEM_CONSTEXPR error_category() BOOST_NOEXCEPT: id_( 0 ), ps_()
+    BOOST_SYSTEM_CONSTEXPR error_category() BOOST_NOEXCEPT: id_( 0 ), stdcat_(), sc_init_()
    {
    }

-    explicit BOOST_SYSTEM_CONSTEXPR error_category( boost::ulong_long_type id ) BOOST_NOEXCEPT: id_( id ), ps_()
+    explicit BOOST_SYSTEM_CONSTEXPR error_category( boost::ulong_long_type id ) BOOST_NOEXCEPT: id_( id ), stdcat_(), sc_init_()
    {
    }

@@ -158,14 +171,22 @@ public:
    }

 #if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    void init_stdcat() const;
+
 # if defined(__SUNPRO_CC) // trailing __global is not supported
    operator std::error_category const & () const;
 # else
    operator std::error_category const & () const BOOST_SYMBOL_VISIBLE;
 # endif
+
 #endif
 };

+#if defined(BOOST_MSVC) && BOOST_MSVC < 1900
+#pragma warning(pop)
+#endif
+
 #if ( defined( BOOST_GCC ) && BOOST_GCC >= 40600 ) || defined( BOOST_CLANG )
 #pragma GCC diagnostic pop
 #endif
--- a/include/boost/system/detail/error_category_impl.hpp
+++ b/include/boost/system/detail/error_category_impl.hpp
@@ -97,26 +97,75 @@ inline char const * error_category::message( int ev, char * buffer, std::size_t

 #if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)

-#include <boost/system/detail/std_category.hpp>
+#include <boost/system/detail/std_category_impl.hpp>
+#include <new>
+
+#if !defined(BOOST_SYSTEM_DISABLE_THREADS)
+# include <mutex>
+#endif

 namespace boost
 {
 namespace system
 {

-inline error_category::operator std::error_category const & () const
+#if !defined(BOOST_SYSTEM_DISABLE_THREADS)
+
+namespace detail
+{
+
+template<class = void> struct stdcat_mx_holder
+{
+    static std::mutex mx_;
+};
+
+template<class T> std::mutex stdcat_mx_holder<T>::mx_;
+
+} // namespace detail
+
+#endif
+
+inline void error_category::init_stdcat() const
+{
+    static_assert( sizeof( stdcat_ ) >= sizeof( boost::system::detail::std_category ), "sizeof(stdcat_) is not enough for std_category" );
+
+#if defined(BOOST_MSVC) && BOOST_MSVC < 1900
+    // no alignof
+#else
+
+    static_assert( alignof( decltype(stdcat_align_) ) >= alignof( boost::system::detail::std_category ), "alignof(stdcat_) is not enough for std_category" );
+
+#endif
+
+#if !defined(BOOST_SYSTEM_DISABLE_THREADS)
+    std::lock_guard<std::mutex> lk( boost::system::detail::stdcat_mx_holder<>::mx_ );
+#endif
+
+    if( sc_init_.load( std::memory_order_acquire ) == 0 )
+    {
+        ::new( static_cast<void*>( stdcat_ ) ) boost::system::detail::std_category( this, system::detail::id_wrapper<0>() );
+        sc_init_.store( 1, std::memory_order_release );
+    }
+}
+
+#if defined( BOOST_GCC ) && BOOST_GCC >= 40800 && BOOST_GCC < 70000
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wstrict-aliasing"
+#endif
+
+inline BOOST_NOINLINE error_category::operator std::error_category const & () const
 {
    if( id_ == detail::generic_category_id )
    {
 // This condition must be the same as the one in error_condition.hpp
 #if defined(BOOST_SYSTEM_AVOID_STD_GENERIC_CATEGORY)

-    static const boost::system::detail::std_category generic_instance( this, 0x1F4D3 );
-    return generic_instance;
+        static const boost::system::detail::std_category generic_instance( this, system::detail::id_wrapper<0x1F4D3>() );
+        return generic_instance;

 #else

-    return std::generic_category();
+        return std::generic_category();

 #endif
    }
@@ -126,36 +175,28 @@ inline error_category::operator std::error_category const & () const
 // This condition must be the same as the one in error_code.hpp
 #if defined(BOOST_SYSTEM_AVOID_STD_SYSTEM_CATEGORY)

-    static const boost::system::detail::std_category system_instance( this, 0x1F4D7 );
-    return system_instance;
+        static const boost::system::detail::std_category system_instance( this, system::detail::id_wrapper<0x1F4D7>() );
+        return system_instance;

 #else

-    return std::system_category();
+        return std::system_category();

 #endif
    }

-    detail::std_category* p = ps_.load( std::memory_order_acquire );
-
-    if( p != 0 )
+    if( sc_init_.load( std::memory_order_acquire ) == 0 )
    {
-        return *p;
+        init_stdcat();
    }

-    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;
-    }
+    return *static_cast<boost::system::detail::std_category const*>( static_cast<void const*>( stdcat_ ) );
 }

+#if defined( BOOST_GCC ) && BOOST_GCC >= 40800 && BOOST_GCC < 70000
+#pragma GCC diagnostic pop
+#endif
+
 } // namespace system
 } // namespace boost

--- a/include/boost/system/detail/error_code.hpp
+++ b/include/boost/system/detail/error_code.hpp
@@ -21,9 +21,15 @@
 #include <boost/system/detail/append_int.hpp>
 #include <boost/system/detail/snprintf.hpp>
 #include <boost/system/detail/config.hpp>
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+# include <boost/system/detail/std_category.hpp>
+#endif
+
 #include <boost/assert/source_location.hpp>
 #include <boost/cstdint.hpp>
 #include <boost/config.hpp>
+#include <boost/config/workaround.hpp>
 #include <ostream>
 #include <new>
 #include <cstdio>
@@ -52,12 +58,14 @@ namespace system
 //  and error_code containing a pointer to an object of a type derived
 //  from error_category.

+bool operator==( const error_code & code, const error_condition & condition ) BOOST_NOEXCEPT;
 std::size_t hash_value( error_code const & ec );

 class error_code
 {
 private:

+    friend bool operator==( const error_code & code, const error_condition & condition ) BOOST_NOEXCEPT;
    friend std::size_t hash_value( error_code const & ec );

 private:
@@ -109,7 +117,10 @@ public:

    // constructors:

-    BOOST_SYSTEM_CONSTEXPR error_code() BOOST_NOEXCEPT:
+#if !BOOST_WORKAROUND(BOOST_GCC, < 40800)
+    BOOST_CONSTEXPR
+#endif
+    error_code() BOOST_NOEXCEPT:
        d1_(), lc_flags_( 0 )
    {
    }
@@ -139,28 +150,35 @@ public:
        *this = make_error_code( e );
    }

-    template<class ErrorCodeEnum> error_code( ErrorCodeEnum e, source_location const * loc,
-        typename detail::enable_if<is_error_code_enum<ErrorCodeEnum>::value>::type* = 0 ) BOOST_NOEXCEPT:
+    error_code( error_code const& ec, source_location const * loc ) BOOST_NOEXCEPT:
        d1_(), lc_flags_( 0 )
    {
-        error_code e2 = make_error_code( e );
+        *this = ec;

-        if( e2.lc_flags_ == 0 || e2.lc_flags_ == 1 )
+        if( ec.lc_flags_ != 0 && ec.lc_flags_ != 1 )
        {
-            *this = e2;
-        }
-        else
-        {
-            *this = error_code( e2.d1_.val_, *e2.d1_.cat_, loc );
+            lc_flags_ = ( loc? reinterpret_cast<boost::uintptr_t>( loc ): 2 ) | ( ec.lc_flags_ & 1 );
        }
    }

 #if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)

    error_code( std::error_code const& ec ) BOOST_NOEXCEPT:
-        lc_flags_( 1 )
+        d1_(), lc_flags_( 0 )
    {
-        ::new( d2_ ) std::error_code( ec );
+#ifndef BOOST_NO_RTTI
+
+        if( detail::std_category const* pc2 = dynamic_cast< detail::std_category const* >( &ec.category() ) )
+        {
+            *this = boost::system::error_code( ec.value(), pc2->original_category() );
+        }
+        else
+
+#endif
+        {
+            ::new( d2_ ) std::error_code( ec );
+            lc_flags_ = 1;
+        }
    }

 #endif
@@ -177,6 +195,11 @@ public:
        *this = error_code( val, cat, loc );
    }

+    void assign( error_code const& ec, source_location const * loc ) BOOST_NOEXCEPT
+    {
+        *this = error_code( ec, loc );
+    }
+
    template<typename ErrorCodeEnum>
        BOOST_SYSTEM_CONSTEXPR typename detail::enable_if<is_error_code_enum<ErrorCodeEnum>::value, error_code>::type &
        operator=( ErrorCodeEnum val ) BOOST_NOEXCEPT
@@ -185,13 +208,6 @@ public:
        return *this;
    }

-    template<typename ErrorCodeEnum>
-        typename detail::enable_if<is_error_code_enum<ErrorCodeEnum>::value, void>::type
-        assign( ErrorCodeEnum val, source_location const * loc ) BOOST_NOEXCEPT
-    {
-        *this = error_code( val, loc );
-    }
-
    BOOST_SYSTEM_CONSTEXPR void clear() BOOST_NOEXCEPT
    {
        *this = error_code();
@@ -387,7 +403,12 @@ public:
    {
 #if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)

-        if( lhs.lc_flags_ == 1 && rhs.lc_flags_ == 1 )
+        bool s1 = lhs.lc_flags_ == 1;
+        bool s2 = rhs.lc_flags_ == 1;
+
+        if( s1 != s2 ) return false;
+
+        if( s1 && s2 )
        {
            std::error_code const& e1 = *reinterpret_cast<std::error_code const*>( lhs.d2_ );
            std::error_code const& e2 = *reinterpret_cast<std::error_code const*>( rhs.d2_ );
@@ -405,7 +426,13 @@ public:
    {
 #if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)

-        if( lhs.lc_flags_ == 1 && rhs.lc_flags_ == 1 )
+        bool s1 = lhs.lc_flags_ == 1;
+        bool s2 = rhs.lc_flags_ == 1;
+
+        if( s1 < s2 ) return true;
+        if( s2 < s1 ) return false;
+
+        if( s1 && s2 )
        {
            std::error_code const& e1 = *reinterpret_cast<std::error_code const*>( lhs.d2_ );
            std::error_code const& e2 = *reinterpret_cast<std::error_code const*>( rhs.d2_ );
@@ -424,48 +451,6 @@ public:
        return !( lhs == rhs );
    }

-    inline friend bool operator==( const error_code & code, const error_condition & condition ) BOOST_NOEXCEPT
-    {
-#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
-
-        if( code.lc_flags_ == 1 )
-        {
-            return static_cast<std::error_code>( code ) == static_cast<std::error_condition>( condition );
-        }
-        else
-
-#endif
-        {
-            return code.category().equivalent( code.value(), condition ) || condition.category().equivalent( code, condition.value() );
-        }
-    }
-
-    inline friend bool operator==( const error_condition & condition, const error_code & code ) BOOST_NOEXCEPT
-    {
-#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
-
-        if( code.lc_flags_ == 1 )
-        {
-            return static_cast<std::error_code>( code ) == static_cast<std::error_condition>( condition );
-        }
-        else
-
-#endif
-        {
-            return code.category().equivalent( code.value(), condition ) || condition.category().equivalent( code, condition.value() );
-        }
-    }
-
-    inline friend bool operator!=( const error_code & lhs, const error_condition & rhs ) BOOST_NOEXCEPT
-    {
-        return !( lhs == rhs );
-    }
-
-    inline friend bool operator!=( const error_condition & lhs, const error_code & rhs ) BOOST_NOEXCEPT
-    {
-        return !( lhs == rhs );
-    }
-
 #if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)

    inline friend bool operator==( std::error_code const & lhs, error_code const & rhs ) BOOST_NOEXCEPT
@@ -668,6 +653,37 @@ public:
    }
 };

+inline bool operator==( const error_code & code, const error_condition & condition ) BOOST_NOEXCEPT
+{
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    if( code.lc_flags_ == 1 )
+    {
+        return static_cast<std::error_code>( code ) == static_cast<std::error_condition>( condition );
+    }
+    else
+
+#endif
+    {
+        return code.category().equivalent( code.value(), condition ) || condition.category().equivalent( code, condition.value() );
+    }
+}
+
+inline bool operator==( const error_condition & condition, const error_code & code ) BOOST_NOEXCEPT
+{
+    return code == condition;
+}
+
+inline bool operator!=( const error_code & lhs, const error_condition & rhs ) BOOST_NOEXCEPT
+{
+    return !( lhs == rhs );
+}
+
+inline bool operator!=( const error_condition & lhs, const error_code & rhs ) BOOST_NOEXCEPT
+{
+    return !( lhs == rhs );
+}
+
 inline std::size_t hash_value( error_code const & ec )
 {
 #if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
--- a/include/boost/system/detail/error_condition.hpp
+++ b/include/boost/system/detail/error_condition.hpp
@@ -261,6 +261,58 @@ public:
        return !( lhs == rhs );
    }

+    //
+
+    template<class E, class N = typename detail::enable_if<std::is_error_condition_enum<E>::value>::type>
+    BOOST_SYSTEM_CONSTEXPR inline friend bool operator==( error_condition const & lhs, E rhs ) BOOST_NOEXCEPT
+    {
+        return lhs == make_error_condition( rhs );
+    }
+
+    template<class E, class N = typename detail::enable_if<std::is_error_condition_enum<E>::value>::type>
+    BOOST_SYSTEM_CONSTEXPR inline friend bool operator==( E lhs, error_condition const & rhs ) BOOST_NOEXCEPT
+    {
+        return make_error_condition( lhs ) == rhs;
+    }
+
+    template<class E, class N = typename detail::enable_if<std::is_error_condition_enum<E>::value>::type>
+    BOOST_SYSTEM_CONSTEXPR inline friend bool operator!=( error_condition const & lhs, E rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+    template<class E, class N = typename detail::enable_if<std::is_error_condition_enum<E>::value>::type>
+    BOOST_SYSTEM_CONSTEXPR inline friend bool operator!=( E lhs, error_condition const & rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+    //
+
+    template<class E, class N1 = void, class N2 = typename detail::enable_if<std::is_error_code_enum<E>::value>::type>
+    inline friend bool operator==( error_condition const & lhs, E rhs ) BOOST_NOEXCEPT
+    {
+        return lhs == make_error_code( rhs );
+    }
+
+    template<class E, class N1 = void, class N2 = typename detail::enable_if<std::is_error_code_enum<E>::value>::type>
+    inline friend bool operator==( E lhs, error_condition const & rhs ) BOOST_NOEXCEPT
+    {
+        return make_error_code( lhs ) == rhs;
+    }
+
+    template<class E, class N1 = void, class N2 = typename detail::enable_if<std::is_error_code_enum<E>::value>::type>
+    inline friend bool operator!=( error_condition const & lhs, E rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
+    template<class E, class N1 = void, class N2 = typename detail::enable_if<std::is_error_code_enum<E>::value>::type>
+    inline friend bool operator!=( E lhs, error_condition const & rhs ) BOOST_NOEXCEPT
+    {
+        return !( lhs == rhs );
+    }
+
 #endif

    std::string to_string() const
--- a/include/boost/system/detail/std_category.hpp
+++ b/include/boost/system/detail/std_category.hpp
@@ -11,9 +11,7 @@
 // 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 <boost/config.hpp>
 #include <system_error>

 //
@@ -27,6 +25,8 @@ namespace system
 namespace detail
 {

+template<unsigned Id> struct id_wrapper {};
+
 class BOOST_SYMBOL_VISIBLE std_category: public std::error_category
 {
 private:
@@ -35,20 +35,29 @@ private:

 public:

-    explicit std_category( boost::system::error_category const * pc, unsigned id ): pc_( pc )
+    boost::system::error_category const & original_category() const BOOST_NOEXCEPT
+    {
+        return *pc_;
+    }
+
+public:
+
+    template<unsigned Id>
+    explicit std_category( boost::system::error_category const * pc, id_wrapper<Id> ): pc_( pc )
    {
-        if( id != 0 )
-        {
 #if defined(_MSC_VER) && defined(_CPPLIB_VER) && _MSC_VER >= 1900 && _MSC_VER < 2000

-            // Poking into the protected _Addr member of std::error_category
-            // is not a particularly good programming practice, but what can
-            // you do
+        // We used to assign to the protected _Addr member of std::error_category
+        // here when Id != 0, but this should never happen now because this code
+        // path is no longer used

-            _Addr = id;
+#if !defined(BOOST_NO_CXX11_STATIC_ASSERT)
+
+        static_assert( Id == 0, "This constructor should only be called with Id == 0 under MS STL 14.0+" );
+
+#endif

 #endif
-        }
    }

    const char * name() const BOOST_NOEXCEPT BOOST_OVERRIDE
@@ -66,72 +75,10 @@ public:
        return pc_->default_error_condition( ev );
    }

-    bool equivalent( int code, const std::error_condition & condition ) const BOOST_NOEXCEPT BOOST_OVERRIDE;
-    bool equivalent( const std::error_code & code, int condition ) const BOOST_NOEXCEPT BOOST_OVERRIDE;
+    inline bool equivalent( int code, const std::error_condition & condition ) const BOOST_NOEXCEPT BOOST_OVERRIDE;
+    inline bool equivalent( const std::error_code & code, int condition ) const BOOST_NOEXCEPT BOOST_OVERRIDE;
 };

-inline bool std_category::equivalent( int code, const std::error_condition & condition ) const BOOST_NOEXCEPT
-{
-    if( condition.category() == *this )
-    {
-        boost::system::error_condition bn( condition.value(), *pc_ );
-        return pc_->equivalent( code, bn );
-    }
-    else if( condition.category() == std::generic_category() || condition.category() == boost::system::generic_category() )
-    {
-        boost::system::error_condition bn( condition.value(), boost::system::generic_category() );
-        return pc_->equivalent( code, bn );
-    }
-
-#ifndef BOOST_NO_RTTI
-
-    else if( std_category const* pc2 = dynamic_cast< std_category const* >( &condition.category() ) )
-    {
-        boost::system::error_condition bn( condition.value(), *pc2->pc_ );
-        return pc_->equivalent( code, bn );
-    }
-
-#endif
-
-    else
-    {
-        return default_error_condition( code ) == condition;
-    }
-}
-
-inline bool std_category::equivalent( const std::error_code & code, int condition ) const BOOST_NOEXCEPT
-{
-    if( code.category() == *this )
-    {
-        boost::system::error_code bc( code.value(), *pc_ );
-        return pc_->equivalent( bc, condition );
-    }
-    else if( code.category() == std::generic_category() || code.category() == boost::system::generic_category() )
-    {
-        boost::system::error_code bc( code.value(), boost::system::generic_category() );
-        return pc_->equivalent( bc, condition );
-    }
-
-#ifndef BOOST_NO_RTTI
-
-    else if( std_category const* pc2 = dynamic_cast< std_category const* >( &code.category() ) )
-    {
-        boost::system::error_code bc( code.value(), *pc2->pc_ );
-        return pc_->equivalent( bc, condition );
-    }
-
-#endif
-
-    else if( *pc_ == boost::system::generic_category() )
-    {
-        return std::generic_category().equivalent( code, condition );
-    }
-    else
-    {
-        return false;
-    }
-}
-
 } // namespace detail

 } // namespace system
--- a/include/boost/system/detail/std_category_impl.hpp
+++ b/include/boost/system/detail/std_category_impl.hpp
@@ -0,0 +1,97 @@
+#ifndef BOOST_SYSTEM_DETAIL_STD_CATEGORY_IMPL_HPP_INCLUDED
+#define BOOST_SYSTEM_DETAIL_STD_CATEGORY_IMPL_HPP_INCLUDED
+
+// Support for interoperability between Boost.System and <system_error>
+//
+// Copyright 2018, 2021 Peter Dimov
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// See library home page at http://www.boost.org/libs/system
+
+#include <boost/system/detail/std_category.hpp>
+#include <boost/system/detail/error_condition.hpp>
+#include <boost/system/detail/error_code.hpp>
+#include <boost/system/detail/generic_category.hpp>
+
+//
+
+namespace boost
+{
+
+namespace system
+{
+
+namespace detail
+{
+
+inline bool std_category::equivalent( int code, const std::error_condition & condition ) const BOOST_NOEXCEPT
+{
+    if( condition.category() == *this )
+    {
+        boost::system::error_condition bn( condition.value(), *pc_ );
+        return pc_->equivalent( code, bn );
+    }
+    else if( condition.category() == std::generic_category() || condition.category() == boost::system::generic_category() )
+    {
+        boost::system::error_condition bn( condition.value(), boost::system::generic_category() );
+        return pc_->equivalent( code, bn );
+    }
+
+#ifndef BOOST_NO_RTTI
+
+    else if( std_category const* pc2 = dynamic_cast< std_category const* >( &condition.category() ) )
+    {
+        boost::system::error_condition bn( condition.value(), *pc2->pc_ );
+        return pc_->equivalent( code, bn );
+    }
+
+#endif
+
+    else
+    {
+        return default_error_condition( code ) == condition;
+    }
+}
+
+inline bool std_category::equivalent( const std::error_code & code, int condition ) const BOOST_NOEXCEPT
+{
+    if( code.category() == *this )
+    {
+        boost::system::error_code bc( code.value(), *pc_ );
+        return pc_->equivalent( bc, condition );
+    }
+    else if( code.category() == std::generic_category() || code.category() == boost::system::generic_category() )
+    {
+        boost::system::error_code bc( code.value(), boost::system::generic_category() );
+        return pc_->equivalent( bc, condition );
+    }
+
+#ifndef BOOST_NO_RTTI
+
+    else if( std_category const* pc2 = dynamic_cast< std_category const* >( &code.category() ) )
+    {
+        boost::system::error_code bc( code.value(), *pc2->pc_ );
+        return pc_->equivalent( bc, condition );
+    }
+
+#endif
+
+    else if( *pc_ == boost::system::generic_category() )
+    {
+        return std::generic_category().equivalent( code, condition );
+    }
+    else
+    {
+        return false;
+    }
+}
+
+} // namespace detail
+
+} // namespace system
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SYSTEM_DETAIL_STD_CATEGORY_IMPL_HPP_INCLUDED
--- a/include/boost/system/detail/system_category_condition_win32.hpp
+++ b/include/boost/system/detail/system_category_condition_win32.hpp
@@ -59,6 +59,7 @@ inline int system_category_condition_win32( int ev ) BOOST_NOEXCEPT
    case ERROR_ACCESS_DENIED_: return permission_denied;
    case ERROR_ALREADY_EXISTS_: return file_exists;
    case ERROR_BAD_NETPATH_: return no_such_file_or_directory;
+    case ERROR_BAD_NET_NAME_: return no_such_file_or_directory;
    case ERROR_BAD_UNIT_: return no_such_device;
    case ERROR_BROKEN_PIPE_: return broken_pipe;
    case ERROR_BUFFER_OVERFLOW_: return filename_too_long;
@@ -75,6 +76,7 @@ inline int system_category_condition_win32( int ev ) BOOST_NOEXCEPT
    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_FILENAME_EXCED_RANGE_: return filename_too_long;
    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;
@@ -100,12 +102,16 @@ inline int system_category_condition_win32( int ev ) BOOST_NOEXCEPT
    case ERROR_REPARSE_TAG_INVALID_: return invalid_argument;
    case ERROR_RETRY_: return resource_unavailable_try_again;
    case ERROR_SEEK_: return io_error;
+    case ERROR_SEM_TIMEOUT_: return timed_out;
    case ERROR_SHARING_VIOLATION_: return permission_denied;
    case ERROR_NOT_SUPPORTED_: return not_supported; // WinError.h: "The request is not supported."
+    case ERROR_TIMEOUT_: return timed_out;
    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 258: return timed_out; // WAIT_TIMEOUT
+
    case WSAEACCES_: return permission_denied;
    case WSAEADDRINUSE_: return address_in_use;
    case WSAEADDRNOTAVAIL_: return address_not_available;
--- a/include/boost/system/errc.hpp
+++ b/include/boost/system/errc.hpp
@@ -16,6 +16,7 @@
 #include <boost/system/detail/generic_category.hpp>
 #include <boost/system/detail/error_category_impl.hpp>
 #include <boost/system/detail/config.hpp>
+#include <boost/assert/source_location.hpp>
 #include <boost/config.hpp>

 namespace boost
@@ -35,6 +36,12 @@ BOOST_SYSTEM_CONSTEXPR inline error_code make_error_code( errc_t e ) BOOST_NOEXC
    return error_code( e, generic_category() );
 }

+// explicit conversion:
+inline error_code make_error_code( errc_t e, boost::source_location const * loc ) BOOST_NOEXCEPT
+{
+    return error_code( e, generic_category(), loc );
+}
+
 // implicit conversion:
 BOOST_SYSTEM_CONSTEXPR inline error_condition make_error_condition( errc_t e ) BOOST_NOEXCEPT
 {
--- a/include/boost/system/result.hpp
+++ b/include/boost/system/result.hpp
@@ -18,6 +18,7 @@
 #include <utility>
 #include <iosfwd>
 #include <system_error>
+#include <exception>

 //

@@ -35,12 +36,34 @@ namespace system

 BOOST_NORETURN BOOST_NOINLINE inline void throw_exception_from_error( error_code const & e, boost::source_location const& loc )
 {
-    boost::throw_exception( system_error( e ), loc );
+    boost::throw_with_location( system_error( e ), loc );
+}
+
+BOOST_NORETURN BOOST_NOINLINE inline void throw_exception_from_error( errc::errc_t const & e, boost::source_location const& loc )
+{
+    boost::throw_with_location( system_error( make_error_code( e ) ), loc );
 }

 BOOST_NORETURN BOOST_NOINLINE inline void throw_exception_from_error( std::error_code const & e, boost::source_location const& loc )
 {
-    boost::throw_exception( std::system_error( e ), loc );
+    boost::throw_with_location( std::system_error( e ), loc );
+}
+
+BOOST_NORETURN BOOST_NOINLINE inline void throw_exception_from_error( std::errc const & e, boost::source_location const& loc )
+{
+    boost::throw_with_location( std::system_error( make_error_code( e ) ), loc );
+}
+
+BOOST_NORETURN BOOST_NOINLINE inline void throw_exception_from_error( std::exception_ptr const & p, boost::source_location const& loc )
+{
+    if( p )
+    {
+        std::rethrow_exception( p );
+    }
+    else
+    {
+        boost::throw_with_location( std::bad_exception(), loc );
+    }
 }

 #if defined(__GNUC__) && __GNUC__ >= 7 && __GNUC__ <= 8
@@ -72,6 +95,14 @@ private:

    variant2::variant<T, E> v_;

+public:
+
+    using value_type = T;
+    using error_type = E;
+
+    static constexpr in_place_value_t in_place_value{};
+    static constexpr in_place_error_t in_place_error{};
+
 public:

    // constructors
@@ -112,7 +143,8 @@ public:
    template<class... A, class En = typename std::enable_if<
        std::is_constructible<T, A...>::value &&
        !(detail::is_errc_t<A...>::value && std::is_arithmetic<T>::value) &&
-        !std::is_constructible<E, A...>::value
+        !std::is_constructible<E, A...>::value &&
+        sizeof...(A) >= 1
        >::type>
    explicit constexpr result( A&&... a )
        noexcept( std::is_nothrow_constructible<T, A...>::value )
@@ -123,7 +155,8 @@ public:
    // explicit, error
    template<class... A, class En2 = void, class En = typename std::enable_if<
        !std::is_constructible<T, A...>::value &&
-        std::is_constructible<E, A...>::value
+        std::is_constructible<E, A...>::value &&
+        sizeof...(A) >= 1
        >::type>
    explicit constexpr result( A&&... a )
        noexcept( std::is_nothrow_constructible<E, A...>::value )
@@ -151,6 +184,43 @@ public:
    {
    }

+    // converting
+    template<class T2, class E2, class En = typename std::enable_if<
+        std::is_convertible<T2, T>::value &&
+        std::is_convertible<E2, E>::value
+        >::type>
+    BOOST_CXX14_CONSTEXPR result( result<T2, E2> const& r2 )
+        noexcept(
+            std::is_nothrow_constructible<T, T2 const&>::value &&
+            std::is_nothrow_constructible<E, E2>::value &&
+            std::is_nothrow_default_constructible<E2>::value &&
+            std::is_nothrow_copy_constructible<E2>::value )
+        : v_( in_place_error, r2.error() )
+    {
+        if( r2 )
+        {
+            v_.template emplace<0>( *r2 );
+        }
+    }
+
+    template<class T2, class E2, class En = typename std::enable_if<
+        std::is_convertible<T2, T>::value &&
+        std::is_convertible<E2, E>::value
+        >::type>
+    BOOST_CXX14_CONSTEXPR result( result<T2, E2>&& r2 )
+        noexcept(
+            std::is_nothrow_constructible<T, T2&&>::value &&
+            std::is_nothrow_constructible<E, E2>::value &&
+            std::is_nothrow_default_constructible<E2>::value &&
+            std::is_nothrow_copy_constructible<E2>::value )
+        : v_( in_place_error, r2.error() )
+    {
+        if( r2 )
+        {
+            v_.template emplace<0>( std::move( *r2 ) );
+        }
+    }
+
    // queries

    constexpr bool has_value() const noexcept
@@ -160,7 +230,7 @@ public:

    constexpr bool has_error() const noexcept
    {
-        return v_.index() != 0;
+        return v_.index() == 1;
    }

    constexpr explicit operator bool() const noexcept
@@ -331,6 +401,14 @@ public:
        return has_error()? variant2::unsafe_get<1>( v_ ): E();
    }

+    // emplace
+
+    template<class... A>
+    BOOST_CXX14_CONSTEXPR T& emplace( A&&... a )
+    {
+        return v_.template emplace<0>( std::forward<A>(a)... );
+    }
+
    // swap

    BOOST_CXX14_CONSTEXPR void swap( result& r )
@@ -382,6 +460,14 @@ private:

    variant2::variant<variant2::monostate, E> v_;

+public:
+
+    using value_type = void;
+    using error_type = E;
+
+    static constexpr in_place_value_t in_place_value{};
+    static constexpr in_place_error_t in_place_error{};
+
 public:

    // constructors
@@ -449,7 +535,7 @@ public:

    constexpr bool has_error() const noexcept
    {
-        return v_.index() != 0;
+        return v_.index() == 1;
    }

    constexpr explicit operator bool() const noexcept
@@ -495,6 +581,13 @@ public:
        return has_error()? variant2::unsafe_get<1>( v_ ): E();
    }

+    // emplace
+
+    BOOST_CXX14_CONSTEXPR void emplace()
+    {
+        v_.template emplace<0>();
+    }
+
    // swap

    BOOST_CXX14_CONSTEXPR void swap( result& r )
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -15,6 +15,7 @@ macro(system_run s1)
  boost_test(SOURCES ${s1} ${ARGN})
  boost_test(SOURCES ${s1} ${ARGN} COMPILE_DEFINITIONS BOOST_NO_ANSI_APIS NAME ${n1}_no_ansi)
  boost_test(SOURCES ${s1} ${ARGN} COMPILE_DEFINITIONS BOOST_SYSTEM_USE_UTF8 NAME ${n1}_utf8)
+  boost_test(SOURCES ${s1} ${ARGN} COMPILE_DEFINITIONS BOOST_SYSTEM_DISABLE_THREADS NAME ${n1}_nthr)

 endmacro()

@@ -116,6 +117,23 @@ boost_test(TYPE run SOURCES ec_wstream_test.cpp)

 boost_test(TYPE run SOURCES std_interop_test12.cpp)

+boost_test(TYPE run SOURCES errc_test4.cpp)
+
+boost_test(TYPE run SOURCES std_interop_test13.cpp)
+boost_test(TYPE run SOURCES std_interop_test14.cpp)
+
+boost_test(TYPE run SOURCES ec_location_test3.cpp)
+boost_test(TYPE run SOURCES ec_location_test4.cpp)
+
+boost_test(TYPE compile SOURCES constexpr_test2.cpp)
+
+boost_test(TYPE run SOURCES error_code_test3.cpp)
+boost_test(TYPE run SOURCES std_interop_test15.cpp)
+
+boost_test(TYPE run SOURCES win32_generic_test.cpp)
+
+boost_test(TYPE run SOURCES ec_hash_value_test.cpp)
+
 # result

 set(BOOST_TEST_COMPILE_FEATURES cxx_std_11)
@@ -134,3 +152,7 @@ boost_test(TYPE run SOURCES result_eq.cpp)
 boost_test(TYPE run SOURCES result_range_for.cpp)
 boost_test(TYPE run SOURCES result_value_construct2.cpp)
 boost_test(TYPE run SOURCES result_error_construct2.cpp)
+boost_test(TYPE run SOURCES result_convert_construct.cpp)
+boost_test(TYPE run SOURCES result_typedefs.cpp)
+boost_test(TYPE run SOURCES result_value_construct3.cpp)
+boost_test(TYPE run SOURCES result_error_construct3.cpp)
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -33,6 +33,7 @@ rule system-run ( sources + )
    result += [ run $(sources) : : : <library>/boost/system//boost_system <link>shared : $(sources[1]:B)_shared ] ;
    result += [ run $(sources) : : : <define>BOOST_NO_ANSI_APIS : $(sources[1]:B)_no_ansi ] ;
    result += [ run $(sources) : : : <define>BOOST_SYSTEM_USE_UTF8 : $(sources[1]:B)_utf8 ] ;
+    result += [ run $(sources) : : : <define>BOOST_SYSTEM_DISABLE_THREADS : $(sources[1]:B)_nthr ] ;

    return $(result) ;
 }
@@ -61,7 +62,11 @@ run single_instance_test.cpp single_instance_lib1 single_instance_lib2 : : : <li
 run single_instance_test.cpp single_instance_lib1 single_instance_lib2 : : : <link>shared : single_instance_lib_shared ;

 system-run before_main_test.cpp ;
-run-fail throws_assign_fail.cpp ;
+
+run-fail throws_assign_fail.cpp : : :
+    # GCC 12 catches this at compile time with a warning
+    <toolset>gcc,<variant>release:<build>no ;
+
 system-run constexpr_test.cpp ;
 system-run win32_hresult_test.cpp ;

@@ -140,11 +145,28 @@ run ec_wstream_test.cpp ;

 run std_interop_test12.cpp ;

+run errc_test4.cpp ;
+
+run std_interop_test13.cpp ;
+run std_interop_test14.cpp ;
+
+run ec_location_test3.cpp ;
+run ec_location_test4.cpp ;
+
+compile constexpr_test2.cpp ;
+
+run error_code_test3.cpp ;
+run std_interop_test15.cpp ;
+
+run win32_generic_test.cpp ;
+
+run ec_hash_value_test.cpp ;
+
 # result

 import ../../config/checks/config : requires ;

-CPP11 = [ requires cxx11_variadic_templates cxx11_template_aliases cxx11_decltype cxx11_constexpr cxx11_noexcept ] ;
+CPP11 = [ requires cxx11_variadic_templates cxx11_template_aliases cxx11_decltype cxx11_constexpr cxx11_noexcept ] <toolset>gcc-4.7:<build>no ;

 run result_default_construct.cpp : : : $(CPP11) ;
 run result_value_construct.cpp : : : $(CPP11) ;
@@ -161,3 +183,8 @@ run result_range_for.cpp : : : $(CPP11) ;
 run result_value_construct2.cpp : : : $(CPP11) ;
 run result_error_construct2.cpp : : : $(CPP11) ;
 run result_errc_construct.cpp : : : $(CPP11) ;
+run result_convert_construct.cpp : : : $(CPP11) ;
+run result_typedefs.cpp : : : $(CPP11) ;
+run result_value_construct3.cpp : : : $(CPP11) ;
+run result_error_construct3.cpp : : : $(CPP11) ;
+run result_emplace.cpp : : : $(CPP11) ;
--- a/test/constexpr_test2.cpp
+++ b/test/constexpr_test2.cpp
@@ -0,0 +1,35 @@
+// Copyright 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/error_code.hpp>
+#include <boost/config.hpp>
+#include <boost/config/pragma_message.hpp>
+
+#if defined(BOOST_GCC) && BOOST_GCC >= 40700 && BOOST_GCC < 40800
+
+BOOST_PRAGMA_MESSAGE("Skipping test, BOOST_GCC is 407xx")
+
+#else
+
+struct X
+{
+    boost::system::error_code ec;
+};
+
+X const& f()
+{
+#if defined(BOOST_CLANG_VERSION) && BOOST_CLANG_VERSION < 30900
+
+    BOOST_STATIC_CONSTEXPR X x = {};
+    return x;
+
+#else
+
+    BOOST_STATIC_CONSTEXPR X x;
+    return x;
+
+#endif
+}
+
+#endif
--- a/test/ec_hash_value_test.cpp
+++ b/test/ec_hash_value_test.cpp
@@ -0,0 +1,132 @@
+// Copyright 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/error_code.hpp>
+#include <boost/system/generic_category.hpp>
+#include <boost/system/system_category.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cerrno>
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+#include <system_error>
+#endif
+
+namespace sys = boost::system;
+
+int main()
+{
+    // normal against normal (equal, system)
+    {
+        sys::error_code e2( 0, sys::system_category() );
+        sys::error_code e3( e2.value(), e2.category() );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // normal against normal (equal, generic)
+    {
+        sys::error_code e2( EINVAL, sys::generic_category() );
+        sys::error_code e3( e2.value(), e2.category() );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // normal against normal (inequal, value, generic)
+    {
+        sys::error_code e2( 0, sys::generic_category() );
+        sys::error_code e3( EINVAL, sys::generic_category() );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // normal against normal (inequal, value, system)
+    {
+        sys::error_code e2( 1, sys::system_category() );
+        sys::error_code e3( 2, sys::system_category() );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // normal against normal (inequal, category)
+    {
+        sys::error_code e2( 0, sys::system_category() );
+        sys::error_code e3( 0, sys::generic_category() );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // empty against normal
+    {
+        sys::error_code e2;
+        sys::error_code e3( e2.value(), e2.category() );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    // std:: wrapping against normal
+    {
+        std::error_code e1( EINVAL, std::generic_category() );
+
+        sys::error_code e2( e1 );
+        sys::error_code e3( e2.value(), e2.category() );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // empty against wrapping std:: empty
+    {
+        std::error_code e1;
+
+        sys::error_code e2( e1 );
+        sys::error_code e3;
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // empty against roundtrip via std
+    {
+        sys::error_code e2;
+
+        std::error_code e1( e2 );
+        sys::error_code e3( e1 );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // normal/generic against roundtrip via std
+    {
+        sys::error_code e2( EINVAL, boost::system::generic_category() );
+
+        std::error_code e1( e2 );
+        sys::error_code e3( e1 );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+    // normal/system against roundtrip via std
+    {
+        sys::error_code e2( 0, boost::system::system_category() );
+
+        std::error_code e1( e2 );
+        sys::error_code e3( e1 );
+
+        BOOST_TEST( e2 != e3 || hash_value( e2 ) == hash_value( e3 ) );
+        BOOST_TEST( e2 == e3 || hash_value( e2 ) != hash_value( e3 ) );
+    }
+
+#endif
+
+    return boost::report_errors();
+}
--- a/test/ec_location_test3.cpp
+++ b/test/ec_location_test3.cpp
@@ -0,0 +1,90 @@
+// Copyright 2021, 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cerrno>
+
+int main()
+{
+    int const val = ENOENT;
+    boost::system::error_category const & cat = boost::system::generic_category();
+
+    {
+        boost::system::error_code ec;
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        boost::system::error_code ec2( ec, &loc );
+
+        BOOST_TEST_EQ( ec2, ec );
+
+        BOOST_TEST( !ec2.has_location() );
+        BOOST_TEST_EQ( ec2.location(), boost::source_location() );
+
+        boost::system::error_code ec3( ec2, 0 );
+
+        BOOST_TEST_EQ( ec3, ec2 );
+
+        BOOST_TEST( !ec3.has_location() );
+        BOOST_TEST_EQ( ec3.location(), boost::source_location() );
+    }
+
+    {
+        boost::system::error_code ec( val, cat );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        boost::system::error_code ec2( ec, &loc );
+
+        BOOST_TEST_EQ( ec2, ec );
+
+        BOOST_TEST( ec2.has_location() );
+        BOOST_TEST_EQ( ec2.location(), loc );
+
+        boost::system::error_code ec3( ec2, 0 );
+
+        BOOST_TEST_EQ( ec3, ec2 );
+
+        BOOST_TEST( !ec3.has_location() );
+        BOOST_TEST_EQ( ec3.location(), boost::source_location() );
+    }
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    {
+        std::error_code e2( val, std::generic_category() );
+
+        boost::system::error_code ec( e2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        boost::system::error_code ec2( ec, &loc );
+
+        BOOST_TEST_EQ( ec2, ec );
+
+        BOOST_TEST( !ec2.has_location() );
+        BOOST_TEST_EQ( ec2.location(), boost::source_location() );
+
+        boost::system::error_code ec3( ec2, 0 );
+
+        BOOST_TEST_EQ( ec3, ec2 );
+
+        BOOST_TEST( !ec3.has_location() );
+        BOOST_TEST_EQ( ec3.location(), boost::source_location() );
+    }
+
+#endif
+
+    return boost::report_errors();
+}
--- a/test/ec_location_test4.cpp
+++ b/test/ec_location_test4.cpp
@@ -0,0 +1,93 @@
+// Copyright 2021, 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cerrno>
+
+int main()
+{
+    int const val = ENOENT;
+    boost::system::error_category const & cat = boost::system::generic_category();
+
+    {
+        boost::system::error_code ec;
+        boost::system::error_code ec2( ec );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec.assign( ec, &loc );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        ec.assign( ec, 0 );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+    }
+
+    {
+        boost::system::error_code ec( val, cat );
+        boost::system::error_code ec2( ec );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec.assign( ec, &loc );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), loc );
+
+        ec.assign( ec, 0 );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+    }
+
+#if defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+    {
+        std::error_code e2( val, std::generic_category() );
+
+        boost::system::error_code ec( e2 );
+        boost::system::error_code ec2( ec );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+        ec.assign( ec, &loc );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+
+        ec.assign( ec, 0 );
+
+        BOOST_TEST_EQ( ec, ec2 );
+
+        BOOST_TEST( !ec.has_location() );
+        BOOST_TEST_EQ( ec.location(), boost::source_location() );
+    }
+
+#endif
+
+    return boost::report_errors();
+}
--- a/test/errc_test4.cpp
+++ b/test/errc_test4.cpp
@@ -0,0 +1,17 @@
+// Copyright 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/errc.hpp>
+#include <boost/assert/source_location.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+int main()
+{
+    BOOST_STATIC_CONSTEXPR boost::source_location loc = BOOST_CURRENT_LOCATION;
+
+    BOOST_TEST( make_error_code( boost::system::errc::no_such_file_or_directory, &loc ).has_location() );
+    BOOST_TEST_EQ( make_error_code( boost::system::errc::no_such_file_or_directory, &loc ).location().to_string(), loc.to_string() );
+
+    return boost::report_errors();
+}
--- a/test/error_code_test3.cpp
+++ b/test/error_code_test3.cpp
@@ -0,0 +1,69 @@
+// Copyright 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/error_code.hpp>
+#include <boost/system/error_condition.hpp>
+#include <boost/system/generic_category.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+namespace sys = boost::system;
+
+enum my_errc
+{
+    enomem_c = ENOMEM
+};
+
+enum my_errn
+{
+    enomem_n = ENOMEM
+};
+
+namespace boost {
+namespace system {
+
+template<> struct is_error_code_enum<my_errc>
+{
+    static const bool value = true;
+};
+
+template<> struct is_error_condition_enum<my_errn>
+{
+    static const bool value = true;
+};
+
+} // namespace system
+} // namespace boost
+
+sys::error_code make_error_code( my_errc e )
+{
+    return sys::error_code( e, sys::generic_category() );
+}
+
+sys::error_condition make_error_condition( my_errn e )
+{
+    return sys::error_condition( e, sys::generic_category() );
+}
+
+int main()
+{
+    sys::error_code ec = make_error_code( sys::errc::not_enough_memory );
+    sys::error_condition en( sys::errc::not_enough_memory );
+
+    BOOST_TEST_EQ( ec, en );
+    BOOST_TEST_EQ( en, ec );
+
+    BOOST_TEST_EQ( ec, enomem_c );
+    BOOST_TEST_EQ( enomem_c, ec );
+
+    BOOST_TEST_EQ( ec, enomem_n );
+    BOOST_TEST_EQ( enomem_n, ec );
+
+    BOOST_TEST_EQ( en, enomem_c );
+    BOOST_TEST_EQ( enomem_c, en );
+
+    BOOST_TEST_EQ( en, enomem_n );
+    BOOST_TEST_EQ( enomem_n, en );
+
+    return boost::report_errors();
+}
--- a/test/result_convert_construct.cpp
+++ b/test/result_convert_construct.cpp
@@ -0,0 +1,202 @@
+// Copyright 2017, 2021, 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/result.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/core/lightweight_test_trait.hpp>
+
+using namespace boost::system;
+
+struct X
+{
+    static int instances;
+
+    int v_;
+
+    X(): v_() { ++instances; }
+
+    X( int v ): v_( v ) { ++instances; }
+
+    X( X const& r ): v_( r.v_ ) { ++instances; }
+
+    X& operator=( X const& ) = delete;
+
+    ~X() { --instances; }
+};
+
+bool operator==( X const & x1, X const & x2 )
+{
+    return x1.v_ == x2.v_;
+}
+
+std::ostream& operator<<( std::ostream& os, X const & x )
+{
+    os << "X:" << x.v_;
+    return os;
+}
+
+int X::instances = 0;
+
+int main()
+{
+    {
+        result<int> r( 5 );
+        result<long> r2 = r;
+
+        BOOST_TEST( r2 ) && BOOST_TEST_EQ( *r2, 5 );
+    }
+
+    {
+        result<int> const r( 6 );
+        result<long> r2 = r;
+
+        BOOST_TEST( r2 ) && BOOST_TEST_EQ( *r2, 6 );
+    }
+
+    {
+        result<long> r2 = result<int>( 7 );
+
+        BOOST_TEST( r2 ) && BOOST_TEST_EQ( *r2, 7 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        result<int> r( 5 );
+        result<X> r2 = r;
+
+        BOOST_TEST( r2 ) && BOOST_TEST_EQ( *r2, 5 );
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        result<int> const r( 6 );
+        result<X> r2 = r;
+
+        BOOST_TEST( r2 ) && BOOST_TEST_EQ( *r2, 6 );
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        result<X> r2 = result<int>( 7 );
+
+        BOOST_TEST( r2 ) && BOOST_TEST_EQ( *r2, 7 );
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        auto ec = make_error_code( errc::invalid_argument );
+
+        result<int> r( ec );
+        result<long> r2 = r;
+
+        BOOST_TEST( !r2 );
+        BOOST_TEST_EQ( r2.error(), ec );
+    }
+
+    {
+        auto ec = make_error_code( errc::invalid_argument );
+
+        result<int> r( ec );
+        result<long> r2 = r;
+
+        BOOST_TEST( !r2 );
+        BOOST_TEST_EQ( r2.error(), ec );
+    }
+
+    {
+        auto ec = make_error_code( errc::invalid_argument );
+
+        result<long> r2 = result<int>( ec );
+
+        BOOST_TEST( !r2 );
+        BOOST_TEST_EQ( r2.error(), ec );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        result<char const*, int> r( "test" );
+        result<std::string, X> r2 = r;
+
+        BOOST_TEST( r2 ) && BOOST_TEST_EQ( *r2, std::string( "test" ) );
+        BOOST_TEST_EQ( X::instances, 0 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        result<char const*, int> const r( "test" );
+        result<std::string, X> r2 = r;
+
+        BOOST_TEST( r2 ) && BOOST_TEST_EQ( *r2, std::string( "test" ) );
+        BOOST_TEST_EQ( X::instances, 0 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        result<std::string, X> r2 = result<char const*, int>( "test" );
+
+        BOOST_TEST( r2 ) && BOOST_TEST_EQ( *r2, std::string( "test" ) );
+        BOOST_TEST_EQ( X::instances, 0 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        result<char const*, int> r( 5 );
+        result<std::string, X> r2 = r;
+
+        BOOST_TEST( !r2 );
+        BOOST_TEST_EQ( r2.error(), X(5) );
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        result<char const*, int> const r( 6 );
+        result<std::string, X> r2 = r;
+
+        BOOST_TEST( !r2 );
+        BOOST_TEST_EQ( r2.error(), X(6) );
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    {
+        result<std::string, X> r2 = result<char const*, int>( 7 );
+
+        BOOST_TEST( !r2 );
+        BOOST_TEST_EQ( r2.error(), X(7) );
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        BOOST_TEST_TRAIT_TRUE((std::is_constructible<result<long>, result<int>>));
+        BOOST_TEST_TRAIT_TRUE((std::is_convertible<result<int>, result<long>>));
+
+        BOOST_TEST_TRAIT_FALSE((std::is_constructible<result<int>, result<void*>>));
+        BOOST_TEST_TRAIT_FALSE((std::is_convertible<result<void*>, result<int>>));
+
+        BOOST_TEST_TRAIT_FALSE((std::is_constructible<result<int>, result<void>>));
+        BOOST_TEST_TRAIT_FALSE((std::is_convertible<result<void>, result<int>>));
+
+        BOOST_TEST_TRAIT_FALSE((std::is_constructible<result<void>, result<int>>));
+        BOOST_TEST_TRAIT_FALSE((std::is_convertible<result<int>, result<void>>));
+
+        BOOST_TEST_TRAIT_FALSE((std::is_constructible<result<int, void*>, result<int, int>>));
+        BOOST_TEST_TRAIT_FALSE((std::is_convertible<result<int, int>, result<int, void*>>));
+    }
+
+    return boost::report_errors();
+}
--- a/test/result_default_construct.cpp
+++ b/test/result_default_construct.cpp
@@ -12,6 +12,11 @@ struct X
 {
 };

+struct Y
+{
+    Y( int );
+};
+
 int main()
 {
    {
@@ -37,5 +42,17 @@ int main()
        BOOST_TEST( !r.has_error() );
    }

+    {
+        BOOST_TEST_TRAIT_TRUE((std::is_default_constructible<result<int>>));
+        BOOST_TEST_TRAIT_TRUE((std::is_default_constructible<result<int, int>>));
+        BOOST_TEST_TRAIT_TRUE((std::is_default_constructible<result<X>>));
+        BOOST_TEST_TRAIT_TRUE((std::is_default_constructible<result<X, int>>));
+        BOOST_TEST_TRAIT_TRUE((std::is_default_constructible<result<void>>));
+        BOOST_TEST_TRAIT_TRUE((std::is_default_constructible<result<void, int>>));
+
+        BOOST_TEST_TRAIT_FALSE((std::is_default_constructible<result<Y>>));
+        BOOST_TEST_TRAIT_FALSE((std::is_default_constructible<result<Y, int>>));
+    }
+
    return boost::report_errors();
 }
--- a/test/result_emplace.cpp
+++ b/test/result_emplace.cpp
@@ -0,0 +1,176 @@
+// Copyright 2017, 2021, 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/result.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <cerrno>
+
+using namespace boost::system;
+
+struct X
+{
+    static int instances;
+
+    int v_;
+
+    explicit X( int v ): v_( v ) { ++instances; }
+
+    X( int v1, int v2 ): v_( v1+v2 ) { ++instances; }
+    X( int v1, int v2, int v3 ): v_( v1+v2+v3 ) { ++instances; }
+
+    X( X const& ) = delete;
+    X& operator=( X const& ) = delete;
+
+    ~X() { --instances; }
+};
+
+int X::instances = 0;
+
+struct Y
+{
+    static int instances;
+
+    Y() noexcept { ++instances; }
+
+    Y( Y const& ) noexcept { ++instances; }
+
+    Y& operator=( Y const& ) = default;
+
+    ~Y() { --instances; }
+};
+
+int Y::instances = 0;
+
+int main()
+{
+    {
+        result<int> r;
+
+        BOOST_TEST( r.has_value() );
+
+        r.emplace( 1 );
+
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST_EQ( r.value(), 1 );
+    }
+
+    {
+        result<int> r( ENOENT, generic_category() );
+
+        BOOST_TEST( !r.has_value() );
+
+        r.emplace( 1 );
+
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST_EQ( r.value(), 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        result<X> r( 0 );
+
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST_EQ( r.value().v_, 0 );
+        BOOST_TEST_EQ( X::instances, 1 );
+
+        r.emplace( 1 );
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST_EQ( r.value().v_, 1 );
+        BOOST_TEST_EQ( X::instances, 1 );
+
+        r.emplace( 1, 2 );
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST_EQ( r.value().v_, 1+2 );
+        BOOST_TEST_EQ( X::instances, 1 );
+
+        r.emplace( 1, 2, 3 );
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST_EQ( r.value().v_, 1+2+3 );
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        result<X> r( ENOENT, generic_category() );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST_EQ( X::instances, 0 );
+
+        r.emplace( 1, 2 );
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST_EQ( r.value().v_, 1+2 );
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+    BOOST_TEST_EQ( Y::instances, 0 );
+
+    {
+        result<int, Y> r( Y{} );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST_EQ( Y::instances, 1 );
+
+        r.emplace( 1 );
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST_EQ( *r, 1 );
+        BOOST_TEST_EQ( Y::instances, 0 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+    BOOST_TEST_EQ( Y::instances, 0 );
+
+    {
+        result<X, Y> r( in_place_error );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST_EQ( X::instances, 0 );
+        BOOST_TEST_EQ( Y::instances, 1 );
+
+        r.emplace( 1, 2, 3 );
+
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST_EQ( r->v_, 1+2+3 );
+        BOOST_TEST_EQ( X::instances, 1 );
+        BOOST_TEST_EQ( Y::instances, 0 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+    BOOST_TEST_EQ( Y::instances, 0 );
+
+    {
+        result<void> r;
+
+        BOOST_TEST( r.has_value() );
+
+        r.emplace();
+        BOOST_TEST( r.has_value() );
+    }
+
+    {
+        result<void> r( ENOENT, generic_category() );
+
+        BOOST_TEST( !r.has_value() );
+
+        r.emplace();
+        BOOST_TEST( r.has_value() );
+    }
+
+    BOOST_TEST_EQ( Y::instances, 0 );
+
+    {
+        result<void, Y> r( in_place_error );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST_EQ( Y::instances, 1 );
+
+        r.emplace();
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST_EQ( Y::instances, 0 );
+    }
+
+    return boost::report_errors();
+}
--- a/test/result_error_construct.cpp
+++ b/test/result_error_construct.cpp
@@ -62,13 +62,13 @@ int main()
        BOOST_TEST( !r.has_value() );
        BOOST_TEST( r.has_error() );

-        BOOST_TEST_EQ( r.error(), std::error_code( EINVAL, generic_category() ) );
+        BOOST_TEST_EQ( r.error(), error_code( EINVAL, generic_category() ) );
    }

    {
        auto ec = make_error_code( errc::invalid_argument );

-        result<std::error_code> r( in_place_error, ec );
+        result<error_code> r( in_place_error, ec );

        BOOST_TEST( !r.has_value() );
        BOOST_TEST( r.has_error() );
@@ -77,12 +77,12 @@ int main()
    }

    {
-        result<std::error_code> r( in_place_error, EINVAL, generic_category() );
+        result<error_code> r( in_place_error, EINVAL, generic_category() );

        BOOST_TEST( !r.has_value() );
        BOOST_TEST( r.has_error() );

-        BOOST_TEST_EQ( r.error(), std::error_code( EINVAL, generic_category() ) );
+        BOOST_TEST_EQ( r.error(), error_code( EINVAL, generic_category() ) );
    }

    BOOST_TEST_EQ( X::instances, 0 );
@@ -140,8 +140,8 @@ int main()
    BOOST_TEST_EQ( X::instances, 0 );

    {
-        BOOST_TEST_TRAIT_TRUE((std::is_constructible<result<int>, std::error_code>));
-        BOOST_TEST_TRAIT_TRUE((std::is_convertible<std::error_code, result<int>>));
+        BOOST_TEST_TRAIT_TRUE((std::is_constructible<result<int>, error_code>));
+        BOOST_TEST_TRAIT_TRUE((std::is_convertible<error_code, result<int>>));

        BOOST_TEST_TRAIT_TRUE((std::is_constructible<result<std::string, X>, int>));
        BOOST_TEST_TRAIT_FALSE((std::is_convertible<int, result<std::string, X>>));
@@ -178,7 +178,7 @@ int main()
        BOOST_TEST( !r.has_value() );
        BOOST_TEST( r.has_error() );

-        BOOST_TEST_EQ( r.error(), std::error_code( EINVAL, generic_category() ) );
+        BOOST_TEST_EQ( r.error(), error_code( EINVAL, generic_category() ) );
    }

    return boost::report_errors();
--- a/test/result_error_construct2.cpp
+++ b/test/result_error_construct2.cpp
@@ -41,7 +41,7 @@ int main()
        BOOST_TEST( !r.has_value() );
        BOOST_TEST( r.has_error() );

-        BOOST_TEST_EQ( r.error(), std::error_code( EINVAL, generic_category() ) );
+        BOOST_TEST_EQ( r.error(), error_code( EINVAL, generic_category() ) );
    }

    {
--- a/test/result_error_construct3.cpp
+++ b/test/result_error_construct3.cpp
@@ -0,0 +1,161 @@
+// Copyright 2017, 2021, 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/result.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <string>
+#include <cerrno>
+
+using namespace boost::system;
+
+struct X
+{
+    static int instances;
+
+    int v_;
+
+    X(): v_() { ++instances; }
+
+    explicit X( int v ): v_( v ) { ++instances; }
+
+    X( int v1, int v2 ): v_( v1+v2 ) { ++instances; }
+    X( int v1, int v2, int v3 ): v_( v1+v2+v3 ) { ++instances; }
+
+    X( X const& r ): v_( r.v_ ) { ++instances; }
+
+    X& operator=( X const& ) = delete;
+
+    ~X() { --instances; }
+};
+
+int X::instances = 0;
+
+int main()
+{
+    {
+        auto ec = make_error_code( errc::invalid_argument );
+
+        using R = result<int>;
+        R r( R::in_place_error, ec );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_EQ( r.error(), ec );
+    }
+
+    {
+        using R = result<int>;
+        R r( R::in_place_error, EINVAL, generic_category() );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_EQ( r.error(), error_code( EINVAL, generic_category() ) );
+    }
+
+    {
+        auto ec = make_error_code( errc::invalid_argument );
+
+        using R = result<error_code>;
+        R r( R::in_place_error, ec );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_EQ( r.error(), ec );
+    }
+
+    {
+        using R = result<error_code>;
+        R r( R::in_place_error, EINVAL, generic_category() );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_EQ( r.error(), error_code( EINVAL, generic_category() ) );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        using R = result<std::string, X>;
+        R r( R::in_place_error, 1 );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_EQ( r.error().v_, 1 );
+
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        using R = result<int, X>;
+        R r( R::in_place_error, 1, 2 );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_EQ( r.error().v_, 1+2 );
+
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        using R = result<int, X>;
+        R r( R::in_place_error, 1, 2, 3 );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_EQ( r.error().v_, 1+2+3 );
+
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        using R = result<X, X>;
+        R r( R::in_place_error, 1 );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_EQ( r.error().v_, 1 );
+
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        auto ec = make_error_code( errc::invalid_argument );
+
+        using R = result<void>;
+        R r( R::in_place_error, ec );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_EQ( r.error(), ec );
+    }
+
+    {
+        using R = result<void>;
+        R r( R::in_place_error, EINVAL, generic_category() );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_EQ( r.error(), error_code( EINVAL, generic_category() ) );
+    }
+
+    return boost::report_errors();
+}
--- a/test/result_typedefs.cpp
+++ b/test/result_typedefs.cpp
@@ -0,0 +1,22 @@
+// Copyright 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/result.hpp>
+#include <boost/core/lightweight_test_trait.hpp>
+
+using namespace boost::system;
+
+struct X {};
+
+int main()
+{
+    BOOST_TEST_TRAIT_SAME( result<int>::value_type, int );
+    BOOST_TEST_TRAIT_SAME( result<X>::value_type, X );
+    BOOST_TEST_TRAIT_SAME( result<void>::value_type, void );
+
+    BOOST_TEST_TRAIT_SAME( result<int>::error_type, error_code );
+    BOOST_TEST_TRAIT_SAME( result<int, X>::error_type, X );
+
+    return boost::report_errors();
+}
--- a/test/result_value_access.cpp
+++ b/test/result_value_access.cpp
@@ -5,6 +5,7 @@
 #include <boost/system/result.hpp>
 #include <boost/core/lightweight_test.hpp>
 #include <boost/core/lightweight_test_trait.hpp>
+#include <boost/config.hpp>
 #include <system_error>

 using namespace boost::system;
@@ -32,6 +33,10 @@ BOOST_NORETURN void throw_exception_from_error( Y const &, boost::source_locatio
    throw E();
 }

+struct E2
+{
+};
+
 int main()
 {
    {
@@ -182,6 +187,65 @@ int main()
        BOOST_TEST_EQ( r.operator->(), static_cast<int*>(0) );
    }

+    {
+        result<int, errc::errc_t> const r( in_place_error, errc::invalid_argument );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_NOT( r );
+        BOOST_TEST( !r );
+
+        BOOST_TEST_THROWS( r.value(), system_error );
+
+        BOOST_TEST_EQ( r.operator->(), static_cast<int*>(0) );
+    }
+
+    {
+        result<int, std::errc> const r( std::errc::invalid_argument );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_NOT( r );
+        BOOST_TEST( !r );
+
+        BOOST_TEST_THROWS( r.value(), std::system_error );
+
+        BOOST_TEST_EQ( r.operator->(), static_cast<int*>(0) );
+    }
+
+    {
+        result<int, std::exception_ptr> const r( std::make_exception_ptr( E2() ) );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_NOT( r );
+        BOOST_TEST( !r );
+
+#if defined(BOOST_CLANG_VERSION) && BOOST_CLANG_VERSION < 30600
+#else
+        BOOST_TEST_THROWS( r.value(), E2 );
+#endif
+
+        BOOST_TEST_EQ( r.operator->(), static_cast<int*>(0) );
+    }
+
+    {
+        result<int, std::exception_ptr> const r( in_place_error );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_NOT( r );
+        BOOST_TEST( !r );
+
+        BOOST_TEST_THROWS( r.value(), std::bad_exception );
+
+        BOOST_TEST_EQ( r.operator->(), static_cast<int*>(0) );
+    }
+
    {
        result<X> r( 1 );

@@ -374,5 +438,64 @@ int main()
        BOOST_TEST_EQ( r.operator->(), static_cast<void*>(0) );
    }

+    {
+        result<void, errc::errc_t> const r( in_place_error, errc::invalid_argument );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_NOT( r );
+        BOOST_TEST( !r );
+
+        BOOST_TEST_THROWS( r.value(), system_error );
+
+        BOOST_TEST_EQ( r.operator->(), static_cast<void*>(0) );
+    }
+
+    {
+        result<void, std::errc> const r( std::errc::invalid_argument );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_NOT( r );
+        BOOST_TEST( !r );
+
+        BOOST_TEST_THROWS( r.value(), std::system_error );
+
+        BOOST_TEST_EQ( r.operator->(), static_cast<void*>(0) );
+    }
+
+    {
+        result<void, std::exception_ptr> const r( std::make_exception_ptr( E2() ) );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_NOT( r );
+        BOOST_TEST( !r );
+
+#if defined(BOOST_CLANG_VERSION) && BOOST_CLANG_VERSION < 30600
+#else
+        BOOST_TEST_THROWS( r.value(), E2 );
+#endif
+
+        BOOST_TEST_EQ( r.operator->(), static_cast<void*>(0) );
+    }
+
+    {
+        result<void, std::exception_ptr> const r( in_place_error );
+
+        BOOST_TEST( !r.has_value() );
+        BOOST_TEST( r.has_error() );
+
+        BOOST_TEST_NOT( r );
+        BOOST_TEST( !r );
+
+        BOOST_TEST_THROWS( r.value(), std::bad_exception );
+
+        BOOST_TEST_EQ( r.operator->(), static_cast<void*>(0) );
+    }
+
    return boost::report_errors();
 }
--- a/test/result_value_construct3.cpp
+++ b/test/result_value_construct3.cpp
@@ -0,0 +1,118 @@
+// Copyright 2017, 2021, 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/result.hpp>
+#include <boost/core/lightweight_test.hpp>
+
+using namespace boost::system;
+
+struct X
+{
+    static int instances;
+
+    int v_;
+
+    explicit X( int v ): v_( v ) { ++instances; }
+
+    X( int v1, int v2 ): v_( v1+v2 ) { ++instances; }
+    X( int v1, int v2, int v3 ): v_( v1+v2+v3 ) { ++instances; }
+
+    X( X const& ) = delete;
+    X& operator=( X const& ) = delete;
+
+    ~X() { --instances; }
+};
+
+int X::instances = 0;
+
+int main()
+{
+    {
+        using R = result<int>;
+        R r( R::in_place_value, 0 );
+
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST( !r.has_error() );
+
+        BOOST_TEST_EQ( r.value(), 0 );
+    }
+
+    {
+        using R = result<int, int>;
+        R r( R::in_place_value, 1 );
+
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST( !r.has_error() );
+
+        BOOST_TEST_EQ( *r, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        using R = result<X>;
+        R r( R::in_place_value, 1 );
+
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST( !r.has_error() );
+
+        BOOST_TEST_EQ( r.value().v_, 1 );
+
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        using R = result<X>;
+        R r( R::in_place_value, 1, 2 );
+
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST( !r.has_error() );
+
+        BOOST_TEST_EQ( r.value().v_, 1+2 );
+
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        using R = result<X>;
+        R r( R::in_place_value, 1, 2, 3 );
+
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST( !r.has_error() );
+
+        BOOST_TEST_EQ( r.value().v_, 1+2+3 );
+
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        using R = result<X, X>;
+        R r( R::in_place_value, 1 );
+
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST( !r.has_error() );
+
+        BOOST_TEST_EQ( r->v_, 1 );
+
+        BOOST_TEST_EQ( X::instances, 1 );
+    }
+
+    BOOST_TEST_EQ( X::instances, 0 );
+
+    {
+        using R = result<void>;
+        R r( R::in_place_value );
+
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST( !r.has_error() );
+    }
+
+    return boost::report_errors();
+}
--- a/test/std_interop_test13.cpp
+++ b/test/std_interop_test13.cpp
@@ -0,0 +1,77 @@
+// Copyright 2021, 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/error_code.hpp>
+#include <boost/system/error_category.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/config/pragma_message.hpp>
+#include <boost/config.hpp>
+#include <cerrno>
+
+#if !defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+BOOST_PRAGMA_MESSAGE( "BOOST_SYSTEM_HAS_SYSTEM_ERROR not defined, test will be skipped" )
+int main() {}
+
+#else
+
+#include <system_error>
+
+class my_category_impl: public std::error_category
+{
+public:
+
+    char const* name() const BOOST_NOEXCEPT
+    {
+        return "mycat";
+    }
+
+    std::string message( int /*ev*/ ) const
+    {
+        return "Unknown error";
+    }
+};
+
+std::error_category const& my_category()
+{
+    static my_category_impl mycat;
+    return mycat;
+}
+
+int main()
+{
+    {
+        std::error_code e1( 5, boost::system::system_category() );
+        boost::system::error_code e2( e1 );
+        std::error_code e3( e2 );
+
+        BOOST_TEST_EQ( e1, e3 );
+        BOOST_TEST_EQ( e1.value(), e3.value() );
+        BOOST_TEST_EQ( &e1.category(), &e3.category() );
+    }
+
+    {
+        std::error_code e1( 5, boost::system::generic_category() );
+        boost::system::error_code e2( e1 );
+        std::error_code e3( e2 );
+
+        BOOST_TEST_EQ( e1, e3 );
+        BOOST_TEST_EQ( e1.value(), e3.value() );
+        BOOST_TEST_EQ( &e1.category(), &e3.category() );
+    }
+
+    {
+        std::error_code e1( 5, my_category() );
+        boost::system::error_code e2( e1 );
+        std::error_code e3( e2 );
+
+        BOOST_TEST_EQ( e1, e3 );
+        BOOST_TEST_EQ( e1.value(), e3.value() );
+        BOOST_TEST_EQ( &e1.category(), &e3.category() );
+    }
+
+    return boost::report_errors();
+}
+
+#endif
--- a/test/std_interop_test14.cpp
+++ b/test/std_interop_test14.cpp
@@ -0,0 +1,57 @@
+// Copyright 2021, 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/error_code.hpp>
+#include <boost/system/error_category.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/config/pragma_message.hpp>
+#include <boost/config.hpp>
+#include <cerrno>
+
+#if !defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+BOOST_PRAGMA_MESSAGE( "BOOST_SYSTEM_HAS_SYSTEM_ERROR not defined, test will be skipped" )
+int main() {}
+
+#else
+
+#include <system_error>
+
+class my_category_impl: public boost::system::error_category
+{
+public:
+
+    char const* name() const BOOST_NOEXCEPT
+    {
+        return "mycat";
+    }
+
+    std::string message( int /*ev*/ ) const
+    {
+        return "Unknown error";
+    }
+};
+
+boost::system::error_category const& my_category()
+{
+    static my_category_impl mycat;
+    return mycat;
+}
+
+int main()
+{
+    {
+        boost::system::error_code e1( 5, my_category() );
+        std::error_code e2( e1 );
+        boost::system::error_code e3( e2 );
+
+        BOOST_TEST_EQ( e1, e3 );
+        BOOST_TEST_EQ( e1.value(), e3.value() );
+        BOOST_TEST_EQ( &e1.category(), &e3.category() );
+    }
+
+    return boost::report_errors();
+}
+
+#endif
--- a/test/std_interop_test15.cpp
+++ b/test/std_interop_test15.cpp
@@ -0,0 +1,94 @@
+// Copyright 2021, 2022 Peter Dimov.
+// Distributed under the Boost Software License, Version 1.0.
+// http://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system/error_code.hpp>
+#include <boost/system/error_condition.hpp>
+#include <boost/core/lightweight_test.hpp>
+#include <boost/config/pragma_message.hpp>
+#include <boost/config.hpp>
+#include <boost/config/workaround.hpp>
+
+#if !defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+BOOST_PRAGMA_MESSAGE( "BOOST_SYSTEM_HAS_SYSTEM_ERROR not defined, test will be skipped" )
+int main() {}
+
+#elif defined(BOOST_SYSTEM_AVOID_STD_GENERIC_CATEGORY)
+
+BOOST_PRAGMA_MESSAGE( "Skipping test, BOOST_SYSTEM_AVOID_STD_GENERIC_CATEGORY is defined" )
+int main() {}
+
+#else
+
+#include <system_error>
+
+namespace sys = boost::system;
+
+enum my_errc
+{
+    enomem_c = ENOMEM
+};
+
+enum my_errn
+{
+    enomem_n = ENOMEM
+};
+
+namespace std {
+
+template<> struct is_error_code_enum<my_errc>
+{
+    static const bool value = true;
+};
+
+template<> struct is_error_condition_enum<my_errn>
+{
+    static const bool value = true;
+};
+
+} // namespace std
+
+std::error_code make_error_code( my_errc e )
+{
+    return std::error_code( e, std::generic_category() );
+}
+
+std::error_condition make_error_condition( my_errn e )
+{
+    return std::error_condition( e, std::generic_category() );
+}
+
+int main()
+{
+    sys::error_code ec = make_error_code( sys::errc::not_enough_memory );
+    sys::error_condition en( sys::errc::not_enough_memory );
+
+    BOOST_TEST_EQ( ec, en );
+    BOOST_TEST_EQ( en, ec );
+
+    BOOST_TEST_EQ( ec, enomem_c );
+    BOOST_TEST_EQ( enomem_c, ec );
+
+    BOOST_TEST_EQ( ec, enomem_n );
+    BOOST_TEST_EQ( enomem_n, ec );
+
+    BOOST_TEST_EQ( en, enomem_c );
+    BOOST_TEST_EQ( enomem_c, en );
+
+#if BOOST_WORKAROUND(BOOST_MSVC, == 1800)
+
+    // msvc-12.0 has op== as a member of std::error_condition
+
+#else
+
+    BOOST_TEST_EQ( en, enomem_n );
+
+#endif
+
+    BOOST_TEST_EQ( enomem_n, en );
+
+    return boost::report_errors();
+}
+
+#endif
--- a/test/win32_generic_test.cpp
+++ b/test/win32_generic_test.cpp
@@ -0,0 +1,52 @@
+// Copyright 2022 Peter Dimov
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/system.hpp>
+#include <boost/config.hpp>
+#include <boost/config/pragma_message.hpp>
+
+#if !defined(BOOST_SYSTEM_HAS_SYSTEM_ERROR)
+
+BOOST_PRAGMA_MESSAGE( "Skipping test, BOOST_SYSTEM_HAS_SYSTEM_ERROR is not defined" )
+int main() {}
+
+#elif !defined(BOOST_MSSTL_VERSION) || BOOST_MSSTL_VERSION < 140
+
+BOOST_PRAGMA_MESSAGE( "Skipping test, BOOST_MSSTL_VERSION is not defined or is less than 140" )
+int main() {}
+
+#else
+
+#include <system_error>
+#include <iostream>
+
+int main()
+{
+    namespace sys = boost::system;
+
+    int n = 0;
+
+    for( int i = 0; i < 65000; ++i )
+    {
+        sys::error_code ec1( i, sys::system_category() );
+        sys::error_condition en1 = ec1.default_error_condition();
+
+        std::error_code ec2( i, std::system_category() );
+        std::error_condition en2 = ec2.default_error_condition();
+
+        if( en1 != en2 )
+        {
+            std::cout << i << ": " << en1 << " (" << en1.message() << ") != cond:" << en2.category().name() << ":" << en2.value() << " (" << en2.message() << ")\n";
+
+            if( en2.category() == std::generic_category() && i != 123 ) // msvc-14.0, msvc-14.1 disagree with us on ERROR_INVALID_NAME
+            {
+                ++n;
+            }
+        }
+    }
+
+    return n < 256 ? n: 255;
+}
+
+#endif
Author	SHA1	Message	Date
Peter Dimov	bb60a27b18	Update appveyor.yml	2023-01-12 20:38:54 +02:00
Peter Dimov	e478ba1a2b	Update appveyor.yml	2023-01-12 15:18:11 +02:00
Peter Dimov	50100b0e81	Update CMakeLists.txt	2023-01-12 10:37:55 +02:00
Peter Dimov	bb502f5d67	Merge branch 'develop' into feature/pr-90	2023-01-12 10:36:56 +02:00
Peter Dimov	fa2349eee7	Add CMake tests to Appveyor	2023-01-12 05:45:30 +02:00
Peter Dimov	3d9acaf082	Update CMakeLists.txt	2023-01-12 05:41:30 +02:00
Peter Dimov	c6795eb9d0	Merge branch 'natvis' of https://github.com/vinniefalco/boost-system into feature/pr-90	2023-01-12 05:39:37 +02:00
Peter Dimov	57c295bbf7	Work around Clang 3.5 failures in result_value_access	2023-01-10 05:46:57 +02:00
Peter Dimov	36e3b2c6ae	Work around Clang 3.5..3.8 failure in constexpr_test2	2023-01-10 05:14:36 +02:00
Peter Dimov	583cd8dba2	Update .drone.jsonnet	2023-01-10 04:36:37 +02:00
Peter Dimov	0c2de4cb2a	Update .drone.jsonnet	2023-01-10 04:19:25 +02:00
Peter Dimov	3d595a6e79	Update ci.yml	2023-01-10 04:06:30 +02:00
Peter Dimov	b3faedfe3e	Extend Clang 6 workaround to Clang 7 under Android. Fixes #100 .	2023-01-10 03:09:20 +02:00
Peter Dimov	32bf67f748	error_code wrapping std::error_code should never compare equal to error_code not wrapping std (because of hash_value.) Fixes #101 .	2023-01-07 19:56:34 +02:00
Peter Dimov	5d15aa1267	Add ec_hash_value_test	2023-01-07 19:42:59 +02:00
Peter Dimov	36e1236a0f	Remove _Addr assignment from the constructor of std_category. Fixes #98 .	2022-12-10 22:17:51 +02:00
Peter Dimov	2c20b6e7e5	Work around ERROR_INVALID_NAME failure on msvc-14.0, msvc-14.1	2022-12-10 19:45:14 +02:00
Peter Dimov	103f3b4f00	Print original error code in win32_generic_test	2022-12-10 18:47:54 +02:00
Peter Dimov	14f779e234	Update Win32 translation table. Closes #97 .	2022-12-10 18:38:19 +02:00
Peter Dimov	bfccd4b4d9	Add win32_generic_test. Refs #97 .	2022-12-10 18:24:34 +02:00
Peter Dimov	7ae6b317f3	Only disable C4351 on msvc-12.0 and earlier (refs #96 )	2022-10-26 15:52:18 +03:00
Peter Dimov	9a6d79b841	Update revision history	2022-10-18 04:17:17 +03:00
Peter Dimov	ece71199a9	Document result<>::emplace	2022-10-18 04:15:40 +03:00
Peter Dimov	1e4c050d6c	Add result<>::emplace (refs #85 )	2022-10-18 00:46:59 +03:00
Peter Dimov	21115121bb	Update ci.yml	2022-10-15 04:17:12 +03:00
Peter Dimov	956fa92a53	Update revision history	2022-09-27 20:32:03 +03:00
Peter Dimov	ee318f937f	Document result<>::value_type, error_type, in_place_value, in_place_error. Closes #93 .	2022-09-27 20:23:28 +03:00
Peter Dimov	19f99264de	Document BOOST_SYSTEM_DISABLE_THREADS	2022-09-27 20:20:36 +03:00
Peter Dimov	3261bae6de	Update .drone.jsonnet	2022-09-27 18:58:14 +03:00
Peter Dimov	20ce51858b	Add in_place_value, in_place_error to result<>. Refs #93 .	2022-09-27 18:18:16 +03:00
Peter Dimov	52d7429473	Add value_type, error_type typedefs to result. Refs #93 .	2022-09-26 21:20:40 +03:00
Peter Dimov	53c00841fc	Add support for BOOST_SYSTEM_DISABLE_THREADS (refs #92 )	2022-09-08 18:32:26 +03:00
Peter Dimov	19e27a73e9	Disable failing test for msvc-12.0	2022-08-25 17:38:59 +03:00
Peter Dimov	19020ce925	Disable std_interop_test15 on g++ 4.8/4.9	2022-08-24 23:37:03 +03:00
Peter Dimov	3faf415026	Resolve ambiguities when comparing error_condition with std enums (refs #91 )	2022-08-24 22:56:15 +03:00
Peter Dimov	a2df4d09da	Update error_code_test3.cpp	2022-08-24 21:41:38 +03:00
Peter Dimov	455c6a6332	Add std_interop_test15.cpp	2022-08-24 21:40:20 +03:00
Peter Dimov	efb7634666	Move code/condition comparisons back outside class error_code; fixes #91	2022-08-24 21:10:05 +03:00
Peter Dimov	2bba3fd5e2	Add error_code_test3.cpp	2022-08-24 20:54:20 +03:00
Peter Dimov	8c740705e6	Add missing include	2022-08-21 19:42:10 +03:00
Peter Dimov	4708d95e80	Merge branch 'constexpr-default-ctor' of https://github.com/vinniefalco/boost-system into feature/pr-89	2022-08-21 19:13:48 +03:00
Peter Dimov	867f6d06d0	Add constexpr_test2.cpp	2022-08-21 19:13:12 +03:00
Vinnie Falco	ac1ed1ecc1	error_code default ctor is constexpr in c++11	2022-08-21 08:17:54 -07:00
Vinnie Falco	fe48c3058d	add boost_system.natvis and interface source files	2022-08-19 11:40:36 -07:00
Peter Dimov	cc7c2f7ee4	Return v_.index() == 1 from has_error() to avoid -Wmaybe-uninitialized in error()	2022-08-02 22:44:34 +03:00
Peter Dimov	f2e1db8021	Constrain explicit value and error constructors to not accept zero arguments. Fixes #86 .	2022-07-26 21:49:13 +03:00
Peter Dimov	ede243c42f	Add (negative) tests for default constructability (refs #86 )	2022-07-26 21:35:33 +03:00
Peter Dimov	1558aaa789	Update ci.yml	2022-07-26 20:41:24 +03:00
Peter Dimov	96b876d91a	Add README.md	2022-06-19 02:19:58 +03:00
Peter Dimov	eb9ae4ac69	Update revision history	2022-06-19 01:30:17 +03:00
Peter Dimov	8fd487d496	Update documentation	2022-06-19 01:28:36 +03:00
Peter Dimov	5223c94aa9	Disable throws_assign_fail.cpp for GCC/release, because gcc-12 fails it at compile time	2022-06-18 23:07:41 +03:00
Peter Dimov	a5ee3f291c	Update ci.yml	2022-06-18 21:47:57 +03:00
Peter Dimov	4200b00973	Add converting constructor to `result` (refs #82 )	2022-06-18 18:12:06 +03:00
Peter Dimov	533dfe1688	Update revision history	2022-05-05 21:17:09 +03:00
Peter Dimov	7dec756a6f	Update documentation	2022-05-05 21:15:03 +03:00
Peter Dimov	648a35838b	Remove unnecessary overloads	2022-05-05 05:12:08 +03:00
Peter Dimov	256fe92dbb	Add error_code(error_code const& ec, source_location const* loc) and a corresponding assign	2022-05-05 05:02:37 +03:00
Peter Dimov	5debb8a041	Update revision history	2022-05-05 02:30:07 +03:00
Peter Dimov	a97e5a0546	Move BOOST_NOINLINE to operator std::error_category	2022-04-22 22:41:26 +03:00
Peter Dimov	dc17edfa07	Remove clang-win from appveyor.yml	2022-04-22 21:16:09 +03:00
Peter Dimov	65da7dfd56	Update result_error_construct tests to use sys::error_code instead of (erroneously) std::error_code	2022-04-22 19:52:19 +03:00
Peter Dimov	9279001b8c	Check BOOST_NO_CXX11_HDR_MUTEX when enabling <system_error> integration	2022-04-22 16:49:03 +03:00
Peter Dimov	616e652bd7	Suppress strict-aliasing warning for gcc 4.8 to 6	2022-04-21 21:06:14 +03:00
Peter Dimov	98439855bd	Use static_cast instead of reinterpret_cast	2022-04-21 20:52:02 +03:00
Peter Dimov	986efb1420	Rework conversion to std::error_category to not allocate (closes #78 )	2022-04-21 20:32:25 +03:00
Peter Dimov	28a13571b9	Restore the original system::error_code from std::error_code (refs #79 )	2022-03-18 18:24:01 +02:00
Peter Dimov	65ed1eef66	Add std_interop_test14.cpp (refs #79 )	2022-03-18 08:12:05 +02:00
Peter Dimov	6de20eeebc	Add std_interop_test13	2022-03-18 08:12:05 +02:00
Peter Dimov	0a9266ea7e	Add a comment explaining the one-time allocation in error_category_impl.hpp. Fixes #78 .	2022-03-18 08:11:16 +02:00
Peter Dimov	adb9fc54cb	Remove msvc-14.1 from ci.yml	2022-03-18 07:51:38 +02:00
Peter Dimov	e197c5e803	Update documentation	2022-02-18 19:43:08 +02:00
Peter Dimov	6d7a57a970	Add throw_exception_from_error overload for std::exception_ptr	2022-02-18 02:55:34 +02:00
Peter Dimov	00c71cf388	Add throw_exception_from_error overloads for boost::system::errc, std::errc	2022-02-17 21:55:47 +02:00
Peter Dimov	d930cea481	Update documentation	2022-02-14 02:05:44 +02:00
Peter Dimov	4f09f4adde	Use throw_with_location in throw_exception_from_error	2022-02-13 22:50:20 +02:00
Peter Dimov	abd62362ef	Update documentation	2022-02-09 20:52:23 +02:00
Peter Dimov	8d8e6a90de	Add an errc::make_error_code overload taking a source location	2022-02-09 20:41:34 +02:00
Peter Dimov	716c2ed8ef	Disable result tests on GCC 4.7	2022-02-07 21:40:26 +02:00
Peter Dimov	46a5ecd490	Do not include boost/system/result.hpp on GCC 4.7	2022-02-07 21:38:14 +02:00
Peter Dimov	79f4ef0416	Remove .drone.star	2022-02-07 21:34:11 +02:00
Peter Dimov	d0a8f7fbb7	Squash-merge feature/drone-jsonnet into develop	2022-02-07 21:33:48 +02:00
Peter Dimov	bc07ab1e25	Update .drone.star	2022-02-07 05:09:49 +02:00