Correct CMake version check; VERSION_GREATER 3.18 is true for 3.18.1

Remove windows-2019 from ci.yml
Switch Boost.System to header-only in b2
2025-12-25 08:18:05 +01:00 · 2025-10-19 21:04:45 +03:00 · 2025-07-02 19:12:29 +03:00 · 2025-06-26 16:37:21 +03:00 · 2025-06-26 15:59:21 +03:00 · 2025-02-24 19:46:43 +02:00
19 changed files with 741 additions and 197 deletions
--- a/.drone.jsonnet
+++ b/.drone.jsonnet
@@ -32,6 +32,8 @@ local linux_pipeline(name, image, environment, packages = "", sources = [], arch
            commands:
            [
                'set -e',
+                'uname -a',
+                'echo $DRONE_STAGE_MACHINE',
                '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 []) +
@@ -189,33 +191,54 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
    ),

    linux_pipeline(
-        "Linux 22.04 GCC 12 32 ASAN",
+        "Linux 22.04 GCC 12 32",
        "cppalliance/droneubuntu2204:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '11,14,17,20,2b', ADDRMD: '32' } + asan,
+        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '11,14,17,20,2b', ADDRMD: '32' },
        "g++-12-multilib",
    ),

    linux_pipeline(
-        "Linux 22.04 GCC 12 64 ASAN",
+        "Linux 22.04 GCC 12 64",
        "cppalliance/droneubuntu2204:1",
-        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '11,14,17,20,2b', ADDRMD: '64' } + asan,
+        { TOOLSET: 'gcc', COMPILER: 'g++-12', CXXSTD: '11,14,17,20,2b', ADDRMD: '64' },
        "g++-12-multilib",
    ),

    linux_pipeline(
-        "Linux 23.04 GCC 13 32 UBSAN",
-        "cppalliance/droneubuntu2304:1",
+        "Linux 24.04 GCC 13 32 UBSAN",
+        "cppalliance/droneubuntu2404:1",
        { TOOLSET: 'gcc', COMPILER: 'g++-13', CXXSTD: '11,14,17,20,2b', ADDRMD: '32' } + ubsan,
        "g++-13-multilib",
    ),

    linux_pipeline(
-        "Linux 23.04 GCC 13 64 UBSAN",
-        "cppalliance/droneubuntu2304:1",
+        "Linux 24.04 GCC 13 64 UBSAN",
+        "cppalliance/droneubuntu2404:1",
        { TOOLSET: 'gcc', COMPILER: 'g++-13', CXXSTD: '11,14,17,20,2b', ADDRMD: '64' } + ubsan,
        "g++-13-multilib",
    ),

+    linux_pipeline(
+        "Linux 24.04 GCC 13 32 ASAN",
+        "cppalliance/droneubuntu2404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-13', CXXSTD: '11,14,17,20,2b', ADDRMD: '32' } + asan,
+        "g++-13-multilib",
+    ),
+
+    linux_pipeline(
+        "Linux 24.04 GCC 14 UBSAN",
+        "cppalliance/droneubuntu2404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-14', CXXSTD: '11,14,17,20,2b' } + ubsan,
+        "g++-14-multilib",
+    ),
+
+    linux_pipeline(
+        "Linux 24.04 GCC 14 ASAN",
+        "cppalliance/droneubuntu2404:1",
+        { TOOLSET: 'gcc', COMPILER: 'g++-14', CXXSTD: '11,14,17,20,2b' } + asan,
+        "g++-14-multilib",
+    ),
+
    linux_pipeline(
        "Linux 16.04 Clang 3.5",
        "cppalliance/droneubuntu1604:1",
@@ -266,24 +289,38 @@ local windows_pipeline(name, image, environment, arch = "amd64") =
    ),

    linux_pipeline(
-        "Linux 23.04 Clang 16",
-        "cppalliance/droneubuntu2304:1",
+        "Linux 24.04 Clang 16",
+        "cppalliance/droneubuntu2404:1",
        { TOOLSET: 'clang', COMPILER: 'clang++-16', CXXSTD: '11,14,17,20,2b' },
        "clang-16",
    ),

    linux_pipeline(
-        "Linux 23.10 Clang 17 UBSAN",
-        "cppalliance/droneubuntu2310:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-17', CXXSTD: '11,14,17,20,2b' } + ubsan,
+        "Linux 24.04 Clang 17",
+        "cppalliance/droneubuntu2404:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-17', CXXSTD: '11,14,17,20,2b' },
        "clang-17",
    ),

    linux_pipeline(
-        "Linux 23.10 Clang 17 ASAN",
-        "cppalliance/droneubuntu2310:1",
-        { TOOLSET: 'clang', COMPILER: 'clang++-17', CXXSTD: '11,14,17,20,2b' } + asan,
-        "clang-17",
+        "Linux 24.04 Clang 18 UBSAN",
+        "cppalliance/droneubuntu2404:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-18', CXXSTD: '11,14,17,20,2b' } + ubsan,
+        "clang-18",
+    ),
+
+    linux_pipeline(
+        "Linux 24.04 Clang 18 ASAN",
+        "cppalliance/droneubuntu2404:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-18', CXXSTD: '11,14,17,20,2b' } + asan,
+        "clang-18",
+    ),
+
+    linux_pipeline(
+        "Linux 24.10 Clang 19",
+        "cppalliance/droneubuntu2410:1",
+        { TOOLSET: 'clang', COMPILER: 'clang++-19', CXXSTD: '11,14,17,20,2b' },
+        "clang-19",
    ),

    macos_pipeline(
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -19,38 +19,40 @@ jobs:
        include:
          - toolset: gcc-4.8
            cxxstd: "11"
-            os: ubuntu-latest
            container: ubuntu:18.04
+            os: ubuntu-latest
            install: g++-4.8
          - toolset: gcc-5
            cxxstd: "11,14,1z"
-            os: ubuntu-latest
            container: ubuntu:18.04
+            os: ubuntu-latest
            install: g++-5
          - toolset: gcc-6
            cxxstd: "11,14,1z"
-            os: ubuntu-latest
            container: ubuntu:18.04
+            os: ubuntu-latest
            install: g++-6
          - toolset: gcc-7
            cxxstd: "11,14,17"
-            os: ubuntu-latest
            container: ubuntu:18.04
+            os: ubuntu-latest
          - toolset: gcc-8
            cxxstd: "11,14,17,2a"
-            os: ubuntu-20.04
+            container: ubuntu:20.04
+            os: ubuntu-latest
            install: g++-8
          - toolset: gcc-9
            cxxstd: "11,14,17,2a"
-            os: ubuntu-20.04
+            container: ubuntu:20.04
+            os: ubuntu-latest
          - toolset: gcc-10
            cxxstd: "11,14,17,2a"
-            os: ubuntu-20.04
+            container: ubuntu:20.04
+            os: ubuntu-latest
            install: g++-10
          - toolset: gcc-11
            cxxstd: "11,14,17,2a"
-            os: ubuntu-20.04
-            install: g++-11
+            os: ubuntu-22.04
          - toolset: gcc-12
            cxxstd: "11,14,17,20,2b"
            os: ubuntu-22.04
@@ -58,8 +60,18 @@ jobs:
          - toolset: gcc-13
            cxxstd: "11,14,17,20,2b"
            os: ubuntu-latest
-            container: ubuntu:23.04
+            container: ubuntu:24.04
            install: g++-13
+          - toolset: gcc-14
+            cxxstd: "11,14,17,20,2b"
+            os: ubuntu-latest
+            container: ubuntu:24.04
+            install: g++-14
+          - toolset: gcc-15
+            cxxstd: "11,14,17,20,23,2c"
+            os: ubuntu-latest
+            container: ubuntu:25.04
+            install: g++-15
          - toolset: clang
            compiler: clang++-3.9
            cxxstd: "11,14"
@@ -81,35 +93,45 @@ jobs:
          - toolset: clang
            compiler: clang++-6.0
            cxxstd: "11,14,17"
-            os: ubuntu-20.04
+            container: ubuntu:20.04
+            os: ubuntu-latest
            install: clang-6.0
          - toolset: clang
            compiler: clang++-7
            cxxstd: "11,14,17"
-            os: ubuntu-20.04
+            container: ubuntu:20.04
+            os: ubuntu-latest
            install: clang-7
          - toolset: clang
            compiler: clang++-8
            cxxstd: "11,14,17"
-            os: ubuntu-20.04
+            container: ubuntu:20.04
+            os: ubuntu-latest
            install: clang-8
          - toolset: clang
            compiler: clang++-9
            cxxstd: "11,14,17"
-            os: ubuntu-20.04
+            container: ubuntu:20.04
+            os: ubuntu-latest
            install: clang-9
          - toolset: clang
            compiler: clang++-10
            cxxstd: "11,14,17,2a"
-            os: ubuntu-20.04
+            container: ubuntu:20.04
+            os: ubuntu-latest
+            install: clang-10
          - toolset: clang
            compiler: clang++-11
            cxxstd: "11,14,17,2a"
-            os: ubuntu-20.04
+            container: ubuntu:20.04
+            os: ubuntu-latest
+            install: clang-11
          - toolset: clang
            compiler: clang++-12
            cxxstd: "11,14,17,20"
-            os: ubuntu-20.04
+            container: ubuntu:20.04
+            os: ubuntu-latest
+            install: clang-12
          - toolset: clang
            compiler: clang++-13
            cxxstd: "11,14,17,20,2b"
@@ -131,40 +153,70 @@ jobs:
          - toolset: clang
            compiler: clang++-16
            cxxstd: "11,14,17,20,2b"
-            container: ubuntu:23.04
+            container: ubuntu:24.04
            os: ubuntu-latest
            install: clang-16
          - toolset: clang
            compiler: clang++-17
            cxxstd: "11,14,17,20,2b"
-            container: ubuntu:23.10
+            container: ubuntu:24.04
            os: ubuntu-latest
            install: clang-17
          - toolset: clang
-            cxxstd: "11,14,17,2a"
-            os: macos-11
-          - toolset: clang
+            compiler: clang++-18
            cxxstd: "11,14,17,20,2b"
-            os: macos-12
+            container: ubuntu:24.04
+            os: ubuntu-latest
+            install: clang-18
+          - toolset: clang
+            compiler: clang++-19
+            cxxstd: "11,14,17,20,2b"
+            container: ubuntu:24.04
+            os: ubuntu-latest
+            install: clang-19
+          - toolset: clang
+            compiler: clang++-20
+            cxxstd: "11,14,17,20,23,2c"
+            container: ubuntu:25.04
+            os: ubuntu-latest
+            install: clang-20
          - toolset: clang
            cxxstd: "11,14,17,20,2b"
            os: macos-13
+          - toolset: clang
+            cxxstd: "11,14,17,20,2b"
+            os: macos-14
+          - toolset: clang
+            cxxstd: "11,14,17,20,2b"
+            os: macos-15

    runs-on: ${{matrix.os}}
-    container: ${{matrix.container}}
+
+    container:
+      image: ${{matrix.container}}
+      volumes:
+        - /node20217:/node20217:rw,rshared
+        - ${{ startsWith(matrix.container, 'ubuntu:1') && '/node20217:/__e/node20:ro,rshared' || ' ' }}

    defaults:
      run:
        shell: bash

    steps:
-      - uses: actions/checkout@v3
-
      - name: Setup container environment
        if: matrix.container
        run: |
          apt-get update
-          apt-get -y install sudo python3 git g++
+          apt-get -y install sudo python3 git g++ curl xz-utils
+
+      - name: Install nodejs20glibc2.17
+        if: ${{ startsWith( matrix.container, 'ubuntu:1' ) }}
+        run: |
+          curl -LO https://archives.boost.io/misc/node/node-v20.9.0-linux-x64-glibc-217.tar.xz
+          tar -xf node-v20.9.0-linux-x64-glibc-217.tar.xz --strip-components 1 -C /node20217
+          ldd /__e/node20/bin/node
+
+      - uses: actions/checkout@v4

      - name: Install packages
        if: matrix.install
@@ -209,14 +261,6 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - toolset: msvc-14.0
-            cxxstd: "14"
-            addrmd: 32,64
-            os: windows-2019
-          - toolset: msvc-14.2
-            cxxstd: "14,17,20,latest"
-            addrmd: 32,64
-            os: windows-2019
          - toolset: msvc-14.3
            cxxstd: "14,17,20,latest"
            addrmd: 32,64
@@ -228,7 +272,7 @@ jobs:
          - toolset: gcc
            cxxstd: "11,14,17,2a"
            addrmd: 64
-            os: windows-2019
+            os: windows-2022

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

@@ -268,11 +312,11 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - os: ubuntu-20.04
          - os: ubuntu-22.04
-          - os: macos-11
-          - os: macos-12
+          - os: ubuntu-24.04
          - os: macos-13
+          - os: macos-14
+          - os: macos-15

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

@@ -316,11 +360,11 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - os: ubuntu-20.04
          - os: ubuntu-22.04
-          - os: macos-11
-          - os: macos-12
+          - os: ubuntu-24.04
          - os: macos-13
+          - os: macos-14
+          - os: macos-15

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

@@ -374,11 +418,11 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - os: ubuntu-20.04
          - os: ubuntu-22.04
-          - os: macos-11
-          - os: macos-12
+          - os: ubuntu-24.04
          - os: macos-13
+          - os: macos-14
+          - os: macos-15

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

@@ -430,8 +474,7 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - os: windows-2019
-          - os: windows-2022
+          - os: windows-latest

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

@@ -479,8 +522,7 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - os: windows-2019
-          - os: windows-2022
+          - os: windows-latest

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

@@ -546,8 +588,7 @@ jobs:
      fail-fast: false
      matrix:
        include:
-          - os: windows-2019
-          - os: windows-2022
+          - os: windows-latest

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

--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -22,7 +22,7 @@ target_link_libraries(boost_system

 target_compile_features(boost_system INTERFACE cxx_std_11)

-if(CMAKE_VERSION VERSION_GREATER 3.18 AND CMAKE_GENERATOR MATCHES "Visual Studio")
+if(NOT CMAKE_VERSION VERSION_LESS 3.19 AND CMAKE_GENERATOR MATCHES "Visual Studio")

  file(GLOB_RECURSE boost_system_IDEFILES CONFIGURE_DEPENDS include/*.hpp)
  source_group(TREE ${PROJECT_SOURCE_DIR}/include FILES ${boost_system_IDEFILES} PREFIX "Header Files")
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -17,7 +17,11 @@ environment:
    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
      TOOLSET: msvc-14.1
      CXXSTD: 14,17,latest
-      ADDRMD: 32,64
+      ADDRMD: 32
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
+      TOOLSET: msvc-14.1
+      CXXSTD: 14,17,latest
+      ADDRMD: 64
    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
      ADDPATH: C:\cygwin64\bin;
      TOOLSET: gcc
--- a/build.jam
+++ b/build.jam
@@ -0,0 +1,24 @@
+# Copyright 2023-2024 René Ferdinand Rivera Morell
+# Copyright 2024 Peter Dimov
+# Distributed under the Boost Software License, Version 1.0.
+# https://www.boost.org/LICENSE_1_0.txt
+
+require-b2 5.2 ;
+
+constant boost_dependencies :
+    /boost/assert//boost_assert
+    /boost/config//boost_config
+    /boost/throw_exception//boost_throw_exception
+    /boost/variant2//boost_variant2
+    /boost/winapi//boost_winapi
+    ;
+
+project /boost/system ;
+
+explicit
+    [ alias boost_system : : : : <include>include <library>$(boost_dependencies) ]
+    [ alias all : boost_system test ]
+    ;
+
+call-if : boost-library system
+    ;
--- a/build/Jamfile.v2
+++ b/build/Jamfile.v2
@@ -1,25 +0,0 @@
-# Boost System Library Build Jamfile
-
-# (C) Copyright Beman Dawes 2002, 2006
-
-# Distributed under the Boost Software License, Version 1.0.
-# (See accompanying file LICENSE_1_0.txt or www.boost.org/LICENSE_1_0.txt)
-
-# See library home page at https://www.boost.org/libs/system
-
-project boost/system
-    : source-location ../src
-    : usage-requirements  # pass these requirement to dependents (i.e. users)
-      <link>shared:<define>BOOST_SYSTEM_DYN_LINK=1
-      <link>static:<define>BOOST_SYSTEM_STATIC_LINK=1
-    ;
-
-SOURCES = error_code ;
-
-lib boost_system
-   : $(SOURCES).cpp
-   : <link>shared:<define>BOOST_SYSTEM_DYN_LINK=1
-     <link>static:<define>BOOST_SYSTEM_STATIC_LINK=1
-   ;
-
-boost-install boost_system ;
--- a/doc/system/changes.adoc
+++ b/doc/system/changes.adoc
@@ -8,6 +8,11 @@ https://www.boost.org/LICENSE_1_0.txt
 # Revision History
 :idprefix:

+## Changes in Boost 1.86
+
+* Support `result<T> & fv`, where `fv` returns `void`.
+* Support `result<void> &= fv;`, where `fv` returns `void`.
+
 ## Changes in Boost 1.85

 * {cpp}03 is no longer supported; a {cpp}11 compiler is required. (This includes GCC 4.8 or later, and MSVC 14.0 (VS 2015) or later.)
--- a/include/boost/system/detail/generic_category_message.hpp
+++ b/include/boost/system/detail/generic_category_message.hpp
@@ -39,7 +39,19 @@ inline char const * strerror_r_helper( int r, char const * buffer ) noexcept

 inline char const * generic_error_category_message( int ev, char * buffer, std::size_t len ) noexcept
 {
-    return strerror_r_helper( strerror_r( ev, buffer, len ), buffer );
+    if( buffer != nullptr )
+    {
+        return strerror_r_helper( strerror_r( ev, buffer, len ), buffer );
+    }
+    else
+    {
+        // strerror_r requires non-null buffer pointer
+
+        char tmp[ 1 ] = {};
+        char const* r = strerror_r_helper( strerror_r( ev, tmp, 0 ), buffer );
+
+        return r == tmp? nullptr: r;
+    }
 }

 inline std::string generic_error_category_message( int ev )
--- a/include/boost/system/detail/system_category_message_win32.hpp
+++ b/include/boost/system/detail/system_category_message_win32.hpp
@@ -73,7 +73,7 @@ inline char const * system_category_message_win32( int ev, char * buffer, std::s
        DWORD_ retval = boost::winapi::FormatMessageA(
            FORMAT_MESSAGE_FROM_SYSTEM_ | FORMAT_MESSAGE_IGNORE_INSERTS_,
            NULL,
-            ev,
+            static_cast<DWORD_>(ev),
            MAKELANGID_( LANG_NEUTRAL_, SUBLANG_DEFAULT_ ), // Default language
            buffer,
            static_cast<DWORD_>( len ),
@@ -94,7 +94,7 @@ inline char const * system_category_message_win32( int ev, char * buffer, std::s
        DWORD_ retval = boost::winapi::FormatMessageW(
            FORMAT_MESSAGE_ALLOCATE_BUFFER_ | FORMAT_MESSAGE_FROM_SYSTEM_ | FORMAT_MESSAGE_IGNORE_INSERTS_,
            NULL,
-            ev,
+            static_cast<DWORD_>(ev),
            MAKELANGID_( LANG_NEUTRAL_, SUBLANG_DEFAULT_ ), // Default language
            (LPWSTR_) &lpMsgBuf,
            0,
@@ -152,7 +152,7 @@ inline std::string system_category_message_win32( int ev )
    DWORD_ retval = boost::winapi::FormatMessageW(
        FORMAT_MESSAGE_ALLOCATE_BUFFER_ | FORMAT_MESSAGE_FROM_SYSTEM_ | FORMAT_MESSAGE_IGNORE_INSERTS_,
        NULL,
-        ev,
+        static_cast<DWORD_>(ev),
        MAKELANGID_( LANG_NEUTRAL_, SUBLANG_DEFAULT_ ), // Default language
        (LPWSTR_) &lpMsgBuf,
        0,
@@ -176,7 +176,7 @@ inline std::string system_category_message_win32( int ev )
        return unknown_message_win32( ev );
    }

-    std::string buffer( r, char() );
+    std::string buffer( static_cast<std::size_t>(r), char() );

    r = boost::winapi::WideCharToMultiByte( code_page, 0, lpMsgBuf, -1, &buffer[0], r, NULL, NULL );

@@ -187,12 +187,12 @@ inline std::string system_category_message_win32( int ev )

    --r; // exclude null terminator

-    while( r > 0 && ( buffer[ r-1 ] == '\n' || buffer[ r-1 ] == '\r' ) )
+    while( r > 0 && ( buffer[ static_cast<std::size_t>(r)-1 ] == '\n' || buffer[ static_cast<std::size_t>(r)-1 ] == '\r' ) )
    {
        --r;
    }

-    if( r > 0 && buffer[ r-1 ] == '.' )
+    if( r > 0 && buffer[ static_cast<std::size_t>(r)-1 ] == '.' )
    {
        --r;
    }
--- a/include/boost/system/result.hpp
+++ b/include/boost/system/result.hpp
@@ -73,10 +73,10 @@ BOOST_NORETURN BOOST_NOINLINE inline void throw_exception_from_error( std::excep
 // in_place_*

 using in_place_value_t = variant2::in_place_index_t<0>;
-constexpr in_place_value_t in_place_value{};
+BOOST_INLINE_CONSTEXPR in_place_value_t in_place_value{};

 using in_place_error_t = variant2::in_place_index_t<1>;
-constexpr in_place_error_t in_place_error{};
+BOOST_INLINE_CONSTEXPR in_place_error_t in_place_error{};

 namespace detail
 {
@@ -332,40 +332,28 @@ public:

    BOOST_CXX14_CONSTEXPR T& operator*() noexcept
    {
-        T* p = operator->();
-
-        BOOST_ASSERT( p != 0 );
-
-        return *p;
+        BOOST_ASSERT( has_value() );
+        return *operator->();
    }

    BOOST_CXX14_CONSTEXPR T const& operator*() const noexcept
    {
-        T const* p = operator->();
-
-        BOOST_ASSERT( p != 0 );
-
-        return *p;
+        BOOST_ASSERT( has_value() );
+        return *operator->();
    }

 #else

    BOOST_CXX14_CONSTEXPR T& operator*() & noexcept
    {
-        T* p = operator->();
-
-        BOOST_ASSERT( p != 0 );
-
-        return *p;
+        BOOST_ASSERT( has_value() );
+        return *operator->();
    }

    BOOST_CXX14_CONSTEXPR T const& operator*() const & noexcept
    {
-        T const* p = operator->();
-
-        BOOST_ASSERT( p != 0 );
-
-        return *p;
+        BOOST_ASSERT( has_value() );
+        return *operator->();
    }

    template<class U = T>
@@ -838,11 +826,8 @@ public:

    BOOST_CXX14_CONSTEXPR U& operator*() const noexcept
    {
-        U* p = operator->();
-
-        BOOST_ASSERT( p != 0 );
-
-        return *p;
+        BOOST_ASSERT( has_value() );
+        return *operator->();
    }

    // error access
@@ -1124,7 +1109,8 @@ result<T, E>& operator|=( result<T, E>& r, F&& f )

 template<class T, class E, class F,
    class U = decltype( std::declval<F>()( std::declval<T const&>() ) ),
-    class En = typename std::enable_if<!detail::is_result<U>::value>::type
+    class En1 = typename std::enable_if<!detail::is_result<U>::value>::type,
+    class En2 = typename std::enable_if<!std::is_void<U>::value>::type
 >
 result<U, E> operator&( result<T, E> const& r, F&& f )
 {
@@ -1140,7 +1126,8 @@ result<U, E> operator&( result<T, E> const& r, F&& f )

 template<class T, class E, class F,
    class U = decltype( std::declval<F>()( std::declval<T>() ) ),
-    class En = typename std::enable_if<!detail::is_result<U>::value>::type
+    class En1 = typename std::enable_if<!detail::is_result<U>::value>::type,
+    class En2 = typename std::enable_if<!std::is_void<U>::value>::type
 >
 result<U, E> operator&( result<T, E>&& r, F&& f )
 {
@@ -1154,9 +1141,44 @@ result<U, E> operator&( result<T, E>&& r, F&& f )
    }
 }

+template<class T, class E, class F,
+    class U = decltype( std::declval<F>()( std::declval<T const&>() ) ),
+    class En = typename std::enable_if<std::is_void<U>::value>::type
+>
+result<U, E> operator&( result<T, E> const& r, F&& f )
+{
+    if( r.has_error() )
+    {
+        return r.error();
+    }
+    else
+    {
+        std::forward<F>( f )( *r );
+        return {};
+    }
+}
+
+template<class T, class E, class F,
+    class U = decltype( std::declval<F>()( std::declval<T>() ) ),
+    class En = typename std::enable_if<std::is_void<U>::value>::type
+>
+result<U, E> operator&( result<T, E>&& r, F&& f )
+{
+    if( r.has_error() )
+    {
+        return r.error();
+    }
+    else
+    {
+        std::forward<F>( f )( *std::move( r ) );
+        return {};
+    }
+}
+
 template<class E, class F,
    class U = decltype( std::declval<F>()() ),
-    class En = typename std::enable_if<!detail::is_result<U>::value>::type
+    class En1 = typename std::enable_if<!detail::is_result<U>::value>::type,
+    class En2 = typename std::enable_if<!std::is_void<U>::value>::type
 >
 result<U, E> operator&( result<void, E> const& r, F&& f )
 {
@@ -1170,6 +1192,23 @@ result<U, E> operator&( result<void, E> const& r, F&& f )
    }
 }

+template<class E, class F,
+    class U = decltype( std::declval<F>()() ),
+    class En = typename std::enable_if<std::is_void<U>::value>::type
+>
+result<U, E> operator&( result<void, E> const& r, F&& f )
+{
+    if( r.has_error() )
+    {
+        return r.error();
+    }
+    else
+    {
+        std::forward<F>( f )();
+        return {};
+    }
+}
+
 // result & unary-returning-result

 template<class T, class E, class F,
@@ -1242,6 +1281,20 @@ result<T, E>& operator&=( result<T, E>& r, F&& f )
    return r;
 }

+template<class E, class F,
+    class U = decltype( std::declval<F>()() ),
+    class En = typename std::enable_if<!detail::is_result<U>::value>::type
+>
+result<void, E>& operator&=( result<void, E>& r, F&& f )
+{
+    if( r )
+    {
+        std::forward<F>( f )();
+    }
+
+    return r;
+}
+
 // result &= unary-returning-result

 template<class T, class E, class F,
--- a/src/error_code.cpp
+++ b/src/error_code.cpp
@@ -1,31 +0,0 @@
-//  error_code stub implementation, for compatibility only
-
-//  Copyright Beman Dawes 2002, 2006
-//  Copyright Peter Dimov 2018
-
-//  Distributed under the Boost Software License, Version 1.0. (See accompanying
-//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-
-//  See library home page at http://www.boost.org/libs/system
-
-//----------------------------------------------------------------------------//
-
-// define BOOST_SYSTEM_SOURCE so that <boost/system/config.hpp> knows
-// the library is being built (possibly exporting rather than importing code)
-#define BOOST_SYSTEM_SOURCE
-
-#include <boost/system/config.hpp>
-
-namespace boost
-{
-
-namespace system
-{
-
-BOOST_SYSTEM_DECL void dummy_exported_function()
-{
-}
-
-} // namespace system
-
-} // namespace boost
--- a/test/Jamfile.v2
+++ b/test/Jamfile.v2
@@ -17,6 +17,9 @@ project

  : requirements

+    <library>/boost/system//boost_system
+    <library>/boost/core//boost_core
+
    <toolset>msvc:<warnings-as-errors>on
    <toolset>gcc:<warnings-as-errors>on
    <toolset>clang:<warnings-as-errors>on
--- a/test/cmake_install_test/CMakeLists.txt
+++ b/test/cmake_install_test/CMakeLists.txt
@@ -14,4 +14,4 @@ target_link_libraries(main Boost::system)
 enable_testing()
 add_test(main main)

-add_custom_target(check COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure -C $<CONFIG>)
+add_custom_target(check VERBATIM COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure -C $<CONFIG>)
--- a/test/cmake_subdir_test/CMakeLists.txt
+++ b/test/cmake_subdir_test/CMakeLists.txt
@@ -23,4 +23,4 @@ target_link_libraries(quick Boost::system Boost::core)
 enable_testing()
 add_test(quick quick)

-add_custom_target(check COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure --no-tests=error -C $<CONFIG>)
+add_custom_target(check VERBATIM COMMAND ${CMAKE_CTEST_COMMAND} --output-on-failure --no-tests=error -C $<CONFIG>)
--- a/test/error_code_test2.cpp
+++ b/test/error_code_test2.cpp
@@ -11,26 +11,53 @@ namespace sys = boost::system;

 int main()
 {
-    char buffer[ 1024 ];
-
-    sys::error_code ec;
-
-    BOOST_TEST_EQ( ec.value(), 0 );
-    BOOST_TEST( ec.category() == sys::system_category() );
-    BOOST_TEST_EQ( ec.message(), ec.category().message( ec.value() ) );
-    BOOST_TEST_CSTR_EQ( ec.message( buffer, sizeof( buffer ) ), ec.category().message( ec.value(), buffer, sizeof( buffer ) ) );
-    BOOST_TEST( !ec.failed() );
-    BOOST_TEST( !ec );
-
-    BOOST_TEST_EQ( ec.to_string(), std::string( "system:0" ) );
+    char buffer[ 4096 ], buffer2[ 4096 ];

    {
+        sys::error_code ec;
+
+        BOOST_TEST_EQ( ec.value(), 0 );
+        BOOST_TEST( ec.category() == sys::system_category() );
+
+        BOOST_TEST_EQ( ec.message(), ec.category().message( ec.value() ) );
+        BOOST_TEST_CSTR_EQ( ec.message( buffer, sizeof( buffer ) ), ec.category().message( ec.value(), buffer2, sizeof( buffer2 ) ) );
+        BOOST_TEST_CSTR_EQ( ec.message( buffer, sizeof( buffer ) ), ec.message().c_str() );
+
+        {
+            char const* msg = ec.message( nullptr, 0 );
+
+            if( msg != nullptr )
+            {
+                BOOST_TEST_CSTR_EQ( msg, ec.message().c_str() );
+            }
+        }
+
+        BOOST_TEST( !ec.failed() );
+        BOOST_TEST( !ec );
+
+        BOOST_TEST_EQ( ec.to_string(), std::string( "system:0" ) );
+    }
+
+    {
+        sys::error_code ec;
        sys::error_code ec2( ec );

        BOOST_TEST_EQ( ec2.value(), 0 );
        BOOST_TEST( ec2.category() == sys::system_category() );
+
        BOOST_TEST_EQ( ec2.message(), ec2.category().message( ec2.value() ) );
-        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.category().message( ec2.value(), buffer, sizeof( buffer ) ) );
+        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.category().message( ec2.value(), buffer2, sizeof( buffer2 ) ) );
+        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.message().c_str() );
+
+        {
+            char const* msg = ec2.message( nullptr, 0 );
+
+            if( msg != nullptr )
+            {
+                BOOST_TEST_CSTR_EQ( msg, ec2.message().c_str() );
+            }
+        }
+
        BOOST_TEST( !ec2.failed() );
        BOOST_TEST( !ec2 );

@@ -41,12 +68,25 @@ int main()
    }

    {
+        sys::error_code ec;
        sys::error_code ec2( ec.value(), ec.category() );

        BOOST_TEST_EQ( ec2.value(), 0 );
        BOOST_TEST( ec2.category() == sys::system_category() );
+
        BOOST_TEST_EQ( ec2.message(), ec2.category().message( ec2.value() ) );
-        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.category().message( ec2.value(), buffer, sizeof( buffer ) ) );
+        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.category().message( ec2.value(), buffer2, sizeof( buffer2 ) ) );
+        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.message().c_str() );
+
+        {
+            char const* msg = ec2.message( nullptr, 0 );
+
+            if( msg != nullptr )
+            {
+                BOOST_TEST_CSTR_EQ( msg, ec2.message().c_str() );
+            }
+        }
+
        BOOST_TEST( !ec2.failed() );
        BOOST_TEST( !ec2 );

@@ -61,34 +101,124 @@ int main()

        BOOST_TEST_EQ( ec2.value(), 5 );
        BOOST_TEST( ec2.category() == sys::generic_category() );
+
        BOOST_TEST_EQ( ec2.message(), ec2.category().message( ec2.value() ) );
-        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.category().message( ec2.value(), buffer, sizeof( buffer ) ) );
+        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.category().message( ec2.value(), buffer2, sizeof( buffer2 ) ) );
+        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.message().c_str() );
+
+        {
+            char const* msg = ec2.message( nullptr, 0 );
+
+            if( msg != nullptr )
+            {
+                BOOST_TEST_CSTR_EQ( msg, ec2.message().c_str() );
+            }
+        }
+
        BOOST_TEST( ec2.failed() );
        BOOST_TEST( ec2 );
        BOOST_TEST_NOT( !ec2 );

+        sys::error_code ec;
+
        BOOST_TEST_NE( ec, ec2 );
        BOOST_TEST_NOT( ec == ec2 );

        BOOST_TEST_EQ( ec2.to_string(), std::string( "generic:5" ) );
    }

+    {
+        sys::error_code ec2( -4, sys::generic_category() );
+
+        BOOST_TEST_EQ( ec2.value(), -4 );
+        BOOST_TEST( ec2.category() == sys::generic_category() );
+
+        BOOST_TEST_EQ( ec2.message(), ec2.category().message( ec2.value() ) );
+        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.category().message( ec2.value(), buffer2, sizeof( buffer2 ) ) );
+        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.message().c_str() );
+
+        {
+            char const* msg = ec2.message( nullptr, 0 );
+
+            if( msg != nullptr )
+            {
+                BOOST_TEST_CSTR_EQ( msg, ec2.message().c_str() );
+            }
+        }
+
+        BOOST_TEST( ec2.failed() );
+        BOOST_TEST( ec2 );
+        BOOST_TEST_NOT( !ec2 );
+
+        sys::error_code ec;
+
+        BOOST_TEST_NE( ec, ec2 );
+        BOOST_TEST_NOT( ec == ec2 );
+
+        BOOST_TEST_EQ( ec2.to_string(), std::string( "generic:-4" ) );
+    }
+
    {
        sys::error_code ec2( 5, sys::system_category() );

        BOOST_TEST_EQ( ec2.value(), 5 );
        BOOST_TEST( ec2.category() == sys::system_category() );
+
        BOOST_TEST_EQ( ec2.message(), ec2.category().message( ec2.value() ) );
-        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.category().message( ec2.value(), buffer, sizeof( buffer ) ) );
+        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.category().message( ec2.value(), buffer2, sizeof( buffer2 ) ) );
+        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.message().c_str() );
+
+        {
+            char const* msg = ec2.message( nullptr, 0 );
+
+            if( msg != nullptr )
+            {
+                BOOST_TEST_CSTR_EQ( msg, ec2.message().c_str() );
+            }
+        }
+
        BOOST_TEST( ec2.failed() );
        BOOST_TEST( ec2 );
        BOOST_TEST_NOT( !ec2 );

+        sys::error_code ec;
+
        BOOST_TEST_NE( ec, ec2 );
        BOOST_TEST_NOT( ec == ec2 );

        BOOST_TEST_EQ( ec2.to_string(), std::string( "system:5" ) );
    }

+    {
+        sys::error_code ec2( -4, sys::system_category() );
+
+        BOOST_TEST_EQ( ec2.value(), -4 );
+        BOOST_TEST( ec2.category() == sys::system_category() );
+
+        BOOST_TEST_EQ( ec2.message(), ec2.category().message( ec2.value() ) );
+        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.category().message( ec2.value(), buffer2, sizeof( buffer2 ) ) );
+        BOOST_TEST_CSTR_EQ( ec2.message( buffer, sizeof( buffer ) ), ec2.message().c_str() );
+
+        {
+            char const* msg = ec2.message( nullptr, 0 );
+
+            if( msg != nullptr )
+            {
+                BOOST_TEST_CSTR_EQ( msg, ec2.message().c_str() );
+            }
+        }
+
+        BOOST_TEST( ec2.failed() );
+        BOOST_TEST( ec2 );
+        BOOST_TEST_NOT( !ec2 );
+
+        sys::error_code ec;
+
+        BOOST_TEST_NE( ec, ec2 );
+        BOOST_TEST_NOT( ec == ec2 );
+
+        BOOST_TEST_EQ( ec2.to_string(), std::string( "system:-4" ) );
+    }
+
    return boost::report_errors();
 }
--- a/test/error_condition_test3.cpp
+++ b/test/error_condition_test3.cpp
@@ -11,26 +11,53 @@ namespace sys = boost::system;

 int main()
 {
-    char buffer[ 1024 ];
-
-    sys::error_condition en;
-
-    BOOST_TEST_EQ( en.value(), 0 );
-    BOOST_TEST( en.category() == sys::generic_category() );
-    BOOST_TEST_EQ( en.message(), en.category().message( en.value() ) );
-    BOOST_TEST_CSTR_EQ( en.message( buffer, sizeof( buffer ) ), en.category().message( en.value(), buffer, sizeof( buffer ) ) );
-    BOOST_TEST( !en.failed() );
-    BOOST_TEST( !en );
-
-    BOOST_TEST_EQ( en.to_string(), std::string( "cond:generic:0" ) );
+    char buffer[ 4096 ], buffer2[ 4096 ];

    {
+        sys::error_condition en;
+
+        BOOST_TEST_EQ( en.value(), 0 );
+        BOOST_TEST( en.category() == sys::generic_category() );
+
+        BOOST_TEST_EQ( en.message(), en.category().message( en.value() ) );
+        BOOST_TEST_CSTR_EQ( en.message( buffer, sizeof( buffer ) ), en.category().message( en.value(), buffer2, sizeof( buffer2 ) ) );
+        BOOST_TEST_CSTR_EQ( en.message( buffer, sizeof( buffer ) ), en.message().c_str() );
+
+        {
+            char const* msg = en.message( nullptr, 0 );
+
+            if( msg != nullptr )
+            {
+                BOOST_TEST_CSTR_EQ( msg, en.message().c_str() );
+            }
+        }
+
+        BOOST_TEST( !en.failed() );
+        BOOST_TEST( !en );
+
+        BOOST_TEST_EQ( en.to_string(), std::string( "cond:generic:0" ) );
+    }
+
+    {
+        sys::error_condition en;
        sys::error_condition en2( en );

        BOOST_TEST_EQ( en2.value(), 0 );
        BOOST_TEST( en2.category() == sys::generic_category() );
+
        BOOST_TEST_EQ( en2.message(), en2.category().message( en2.value() ) );
-        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.category().message( en2.value(), buffer, sizeof( buffer ) ) );
+        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.category().message( en2.value(), buffer2, sizeof( buffer2 ) ) );
+        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.message().c_str() );
+
+        {
+            char const* msg = en2.message( nullptr, 0 );
+
+            if( msg != nullptr )
+            {
+                BOOST_TEST_CSTR_EQ( msg, en2.message().c_str() );
+            }
+        }
+
        BOOST_TEST( !en2.failed() );
        BOOST_TEST( !en2 );

@@ -41,12 +68,25 @@ int main()
    }

    {
+        sys::error_condition en;
        sys::error_condition en2( en.value(), en.category() );

        BOOST_TEST_EQ( en2.value(), 0 );
        BOOST_TEST( en2.category() == sys::generic_category() );
+
        BOOST_TEST_EQ( en2.message(), en2.category().message( en2.value() ) );
-        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.category().message( en2.value(), buffer, sizeof( buffer ) ) );
+        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.category().message( en2.value(), buffer2, sizeof( buffer2 ) ) );
+        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.message().c_str() );
+
+        {
+            char const* msg = en2.message( nullptr, 0 );
+
+            if( msg != nullptr )
+            {
+                BOOST_TEST_CSTR_EQ( msg, en2.message().c_str() );
+            }
+        }
+
        BOOST_TEST( !en2.failed() );
        BOOST_TEST( !en2 );

@@ -61,34 +101,124 @@ int main()

        BOOST_TEST_EQ( en2.value(), 5 );
        BOOST_TEST( en2.category() == sys::generic_category() );
+
        BOOST_TEST_EQ( en2.message(), en2.category().message( en2.value() ) );
-        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.category().message( en2.value(), buffer, sizeof( buffer ) ) );
+        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.category().message( en2.value(), buffer2, sizeof( buffer2 ) ) );
+        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.message().c_str() );
+
+        {
+            char const* msg = en2.message( nullptr, 0 );
+
+            if( msg != nullptr )
+            {
+                BOOST_TEST_CSTR_EQ( msg, en2.message().c_str() );
+            }
+        }
+
        BOOST_TEST( en2.failed() );
        BOOST_TEST( en2 );
        BOOST_TEST_NOT( !en2 );

+        sys::error_condition en;
+
        BOOST_TEST_NE( en, en2 );
        BOOST_TEST_NOT( en == en2 );

        BOOST_TEST_EQ( en2.to_string(), std::string( "cond:generic:5" ) );
    }

+    {
+        sys::error_condition en2( -4, sys::generic_category() );
+
+        BOOST_TEST_EQ( en2.value(), -4 );
+        BOOST_TEST( en2.category() == sys::generic_category() );
+
+        BOOST_TEST_EQ( en2.message(), en2.category().message( en2.value() ) );
+        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.category().message( en2.value(), buffer2, sizeof( buffer2 ) ) );
+        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.message().c_str() );
+
+        {
+            char const* msg = en2.message( nullptr, 0 );
+
+            if( msg != nullptr )
+            {
+                BOOST_TEST_CSTR_EQ( msg, en2.message().c_str() );
+            }
+        }
+
+        BOOST_TEST( en2.failed() );
+        BOOST_TEST( en2 );
+        BOOST_TEST_NOT( !en2 );
+
+        sys::error_condition en;
+
+        BOOST_TEST_NE( en, en2 );
+        BOOST_TEST_NOT( en == en2 );
+
+        BOOST_TEST_EQ( en2.to_string(), std::string( "cond:generic:-4" ) );
+    }
+
    {
        sys::error_condition en2( 5, sys::system_category() );

        BOOST_TEST_EQ( en2.value(), 5 );
        BOOST_TEST( en2.category() == sys::system_category() );
+
        BOOST_TEST_EQ( en2.message(), en2.category().message( en2.value() ) );
-        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.category().message( en2.value(), buffer, sizeof( buffer ) ) );
+        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.category().message( en2.value(), buffer2, sizeof( buffer2 ) ) );
+        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.message().c_str() );
+
+        {
+            char const* msg = en2.message( nullptr, 0 );
+
+            if( msg != nullptr )
+            {
+                BOOST_TEST_CSTR_EQ( msg, en2.message().c_str() );
+            }
+        }
+
        BOOST_TEST( en2.failed() );
        BOOST_TEST( en2 );
        BOOST_TEST_NOT( !en2 );

+        sys::error_condition en;
+
        BOOST_TEST_NE( en, en2 );
        BOOST_TEST_NOT( en == en2 );

        BOOST_TEST_EQ( en2.to_string(), std::string( "cond:system:5" ) );
    }

+    {
+        sys::error_condition en2( -4, sys::system_category() );
+
+        BOOST_TEST_EQ( en2.value(), -4 );
+        BOOST_TEST( en2.category() == sys::system_category() );
+
+        BOOST_TEST_EQ( en2.message(), en2.category().message( en2.value() ) );
+        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.category().message( en2.value(), buffer2, sizeof( buffer2 ) ) );
+        BOOST_TEST_CSTR_EQ( en2.message( buffer, sizeof( buffer ) ), en2.message().c_str() );
+
+        {
+            char const* msg = en2.message( nullptr, 0 );
+
+            if( msg != nullptr )
+            {
+                BOOST_TEST_CSTR_EQ( msg, en2.message().c_str() );
+            }
+        }
+
+        BOOST_TEST( en2.failed() );
+        BOOST_TEST( en2 );
+        BOOST_TEST_NOT( !en2 );
+
+        sys::error_condition en;
+
+        BOOST_TEST_NE( en, en2 );
+        BOOST_TEST_NOT( en == en2 );
+
+        BOOST_TEST_EQ( en2.to_string(), std::string( "cond:system:-4" ) );
+    }
+
    return boost::report_errors();
 }
--- a/test/result_and_eq_fn1v.cpp
+++ b/test/result_and_eq_fn1v.cpp
@@ -59,6 +59,13 @@ int& h( int& )
    return x;
 }

+static int fv_called;
+
+void fv()
+{
+    ++fv_called;
+}
+
 int main()
 {
    {
@@ -110,5 +117,25 @@ int main()
        BOOST_TEST( r.has_error() );
    }

+    {
+        result<void> r;
+        fv_called = 0;
+
+        r &= fv;
+
+        BOOST_TEST( r.has_value() );
+        BOOST_TEST_EQ( fv_called, 1 );
+    }
+
+    {
+        result<void, E> r( in_place_error );
+        fv_called = 0;
+
+        r &= fv;
+
+        BOOST_TEST( r.has_error() );
+        BOOST_TEST_EQ( fv_called, 0 );
+    }
+
    return boost::report_errors();
 }
--- a/test/result_and_fn1v.cpp
+++ b/test/result_and_fn1v.cpp
@@ -55,6 +55,20 @@ int k()
    return 7;
 }

+static int fv1_called_with;
+
+void fv1( int x )
+{
+    fv1_called_with = x;
+}
+
+static int fv2_called;
+
+void fv2()
+{
+    ++fv2_called;
+}
+
 int main()
 {
    {
@@ -199,5 +213,119 @@ int main()
        BOOST_TEST( r2.has_error() );
    }

+    {
+        fv1_called_with = 0;
+
+        result<int> r( 1 );
+        result<void> r2 = r & fv1;
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST_EQ( fv1_called_with, 1 );
+    }
+
+    {
+        result<int> const r( 1 );
+        result<void> r2 = r & fv1;
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST_EQ( fv1_called_with, 1 );
+    }
+
+    {
+        fv1_called_with = 0;
+
+        result<void> r2 = result<int>( 1 ) & fv1;
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST_EQ( fv1_called_with, 1 );
+    }
+
+    {
+        fv1_called_with = 0;
+
+        result<int, E> r( in_place_error );
+        result<void, E> r2 = r & fv1;
+
+        BOOST_TEST( r2.has_error() );
+        BOOST_TEST_EQ( fv1_called_with, 0 );
+    }
+
+    {
+        fv1_called_with = 0;
+
+        result<int, E> const r( in_place_error );
+        result<void, E> r2 = r & fv1;
+
+        BOOST_TEST( r2.has_error() );
+        BOOST_TEST_EQ( fv1_called_with, 0 );
+    }
+
+    {
+        fv1_called_with = 0;
+
+        result<void, E> r2 = result<int, E>( in_place_error ) & fv1;
+
+        BOOST_TEST( r2.has_error() );
+        BOOST_TEST_EQ( fv1_called_with, 0 );
+    }
+
+    {
+        result<void> r;
+        fv2_called = 0;
+
+        result<void> r2 = r & fv2;
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST_EQ( fv2_called, 1 );
+    }
+
+    {
+        result<void> const r;
+        fv2_called = 0;
+
+        result<void> r2 = r & fv2;
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST_EQ( fv2_called, 1 );
+    }
+
+    {
+        fv2_called = 0;
+
+        result<void> r2 = result<void>() & fv2;
+
+        BOOST_TEST( r2.has_value() );
+        BOOST_TEST_EQ( fv2_called, 1 );
+    }
+
+    {
+        result<void, E> r( in_place_error );
+        fv2_called = 0;
+
+        result<void, E> r2 = r & fv2;
+
+        BOOST_TEST( r2.has_error() );
+        BOOST_TEST_EQ( fv2_called, 0 );
+    }
+
+    {
+        result<void, E> const r( in_place_error );
+        fv2_called = 0;
+
+        result<void, E> r2 = r & fv2;
+
+        BOOST_TEST( r2.has_error() );
+        BOOST_TEST_EQ( fv2_called, 0 );
+    }
+
+    {
+        fv2_called = 0;
+
+        result<void, E> r2 = result<void, E>( in_place_error ) & fv2;
+
+        BOOST_TEST( r2.has_error() );
+        BOOST_TEST_EQ( fv2_called, 0 );
+    }
+
    return boost::report_errors();
 }
--- a/test/snprintf_test.cpp
+++ b/test/snprintf_test.cpp
@@ -6,6 +6,12 @@
 # pragma GCC diagnostic ignored "-Wformat-truncation"
 #endif

+#if defined(__clang__) && defined(__has_warning)
+# if __has_warning( "-Wformat-truncation" )
+#  pragma clang diagnostic ignored "-Wformat-truncation"
+# endif
+#endif
+
 #include <boost/system/detail/snprintf.hpp>
 #include <boost/core/lightweight_test.hpp>
Author	SHA1	Message	Date
Peter Dimov	bd46fb21f3	Correct CMake version check; VERSION_GREATER 3.18 is true for 3.18.1	2025-10-19 21:04:45 +03:00
Peter Dimov	14c5f52602	Remove windows-2019 from ci.yml	2025-07-02 19:12:29 +03:00
Peter Dimov	7a495bb46d	Switch Boost.System to header-only in b2	2025-06-26 16:37:21 +03:00
Peter Dimov	db00e1848e	Update ci.yml	2025-06-26 15:59:21 +03:00
Peter Dimov	7a49a5d80d	Change assertions in operator* to match documentation; improves codegen slightly in the result<U&> case	2025-02-24 19:46:43 +02:00
Peter Dimov	a0597f4872	Update .drone.jsonnet	2024-12-14 11:02:33 +02:00
Peter Dimov	485be93281	Apply Node20 workaround	2024-12-14 11:01:15 +02:00
Peter Dimov	ee0b15efc4	Update ci.yml	2024-12-14 11:00:28 +02:00
Peter Dimov	09f4eb87e2	Merge pull request #125 from igaztanaga/patch-1 Update system_category_message_win32.hpp	2024-09-05 21:25:41 +03:00
Peter Dimov	3e5ce27719	Add VERBATIM to add_custom_target	2024-08-28 03:02:08 +03:00
Peter Dimov	40bdcea2e5	Update build.jam, build/Jamfile, test/Jamfile	2024-08-28 02:10:03 +03:00
Rene Rivera	19bcfebf37	Sync from upstream.	2024-08-20 09:56:38 -05:00
Ion Gaztañaga	6d58d0bb76	Update system_category_message_win32.hpp Fixes for Wsign-conversion with MinGW64 ("conversion to 'DWORD' {aka 'long unsigned int'} from 'int' may change the sign of the result")	2024-08-19 01:10:16 +02:00
Peter Dimov	a664cd1de6	Update .drone.jsonnet	2024-08-18 11:46:25 +03:00
Peter Dimov	e8a089b664	Update ci.yml	2024-08-17 18:22:21 +03:00
Rene Rivera	75e1a1e28b	Update build deps.	2024-08-09 20:26:47 -05:00
Rene Rivera	5feb280612	Move inter-lib dependencies to a project variable and into the build targets.	2024-07-23 22:34:22 -05:00
Rene Rivera	fc3ab6db97	Update copyright dates.	2024-07-20 22:52:03 -05:00
Rene Rivera	91929719bd	Change all <source> references to <library>.	2024-07-20 21:26:25 -05:00
Rene Rivera	8d0fa396b8	Bump B2 require to 5.2	2024-06-14 11:33:56 -05:00
Rene Rivera	671d0ad41b	Sync from upstream.	2024-06-02 23:25:04 -05:00
Peter Dimov	5d5ecb74a7	Update .drone.jsonnet	2024-06-03 03:01:59 +03:00
Peter Dimov	41ff095c0a	Try to fix the false positive with GCC ASAN	2024-06-03 02:40:13 +03:00
Peter Dimov	38d63aaf7c	strerror_r(ev, tmp, 0) may return tmp	2024-06-02 23:03:24 +03:00
Peter Dimov	d1fb7554c5	Update error_code_test2, error_condition_test3	2024-06-02 22:41:48 +03:00
Peter Dimov	c63bca6eda	Update error_condition_test3.cpp	2024-06-02 22:33:43 +03:00
Peter Dimov	bef2c5ef6a	Update error_code_test2.cpp	2024-06-02 22:26:01 +03:00
Rene Rivera	341f960e72	Sync from upstream.	2024-06-02 13:49:02 -05:00
Mohammad Nejati	4d4f906548	strerror_r requires non-null buffer pointer Fixes -Wnonnull warnings when calling message with a nullptr buffer	2024-06-02 18:21:07 +00:00
Mohammad Nejati	8a92683012	Add tests for calling message with nullptr buffer	2024-06-02 18:20:16 +00:00
Peter Dimov	be5a8ffa80	Disable -Wformat-truncation for Clang in snprintf_test	2024-06-02 19:45:18 +03:00
Peter Dimov	d032ab91fd	Update ci.yml	2024-06-02 18:59:05 +03:00
Rene Rivera	9b82082f76	Add requires-b2 check to top-level build file.	2024-05-05 09:00:01 -05:00
Rene Rivera	3c293f8740	Add missing NO_LIB usage requirements.	2024-04-28 20:17:00 -05:00
Rene Rivera	2feb94ac07	Sync from upstream.	2024-04-20 15:31:42 -05:00
Peter Dimov	8f319f30c6	Update revision history	2024-04-17 03:41:33 +03:00
Rene Rivera	d09b2f5f1d	Sync from upstream.	2024-04-10 07:55:53 -05:00
Peter Dimov	01d46f597e	Update test/result_and_fn1v.cpp	2024-04-09 03:07:07 +03:00
Peter Dimov	93852d1a7e	Support result<void> &= fv. Refs #119 .	2024-04-09 03:01:38 +03:00
Peter Dimov	4aeebd2173	Avoid Appveyor timeout	2024-04-08 21:47:32 +03:00
Peter Dimov	96fef94580	Support result<void> & fv, where fv returns void. Refs #119 .	2024-04-08 18:01:41 +03:00
Peter Dimov	75ab18c9fd	Support result<X> & fv, where fv returns void. Refs #119 .	2024-04-08 17:55:50 +03:00
Peter Dimov	f9a4655ae7	Merge pull request #120 from klemens-morgenstern/patch-1 declared global constants as inline with BOOST_INLINE_CONSTEXPR	2024-04-06 21:48:49 +03:00
Klemens Morgenstern	f6fcb1b690	declared global constants as inline with BOOST_INLINE_CONSTEXPR	2024-04-06 21:54:33 +08:00
Rene Rivera	27a5096b6c	Switch to library requirements instead of source. As source puts extra source in install targets.	2024-03-29 21:15:59 -05:00
Rene Rivera	9cc66841c4	Make the library modular usable.	2024-03-11 08:38:16 -05:00