Update copyright years

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 6.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v2...v6)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/dependabot.yml

@@ -0,0 +1,11 @@
+# To get started with Dependabot version updates, you'll need to specify which
+# package ecosystems to update and where the package manifests are located.
+# Please see the documentation for all configuration options:
+# https://docs.github.com/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file
+
+version: 2
+updates:
+  - package-ecosystem: "github-actions" # See documentation for possible values
+    directory: "/" # Location of package manifests
+    schedule:
+        interval: "weekly"

.github/workflows/ci.yml

@@ -0,0 +1,182 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+      - develop
+      - feature/**
+
+env:
+  UBSAN_OPTIONS: print_stacktrace=1
+
+jobs:
+  posix:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - toolset: gcc-14  # Do not remove! It is the only toolset that tests CMake tests down below
+            cxxstd: "03,11,14,17,20"
+            os: ubuntu-24.04
+          - toolset: gcc-12
+            cxxstd: "03,11,14,17,2a"
+            os: ubuntu-22.04
+            cxxflags: "cxxflags=--coverage -fsanitize=address,leak,undefined -fno-sanitize-recover=undefined"
+            linkflags: "linkflags=--coverage -lasan -lubsan"
+            gcov_tool: "gcov-12"
+          - toolset: clang
+            compiler: clang++-14
+            cxxstd: "03,11,14,17,2a"
+            os: ubuntu-22.04
+
+    runs-on: ${{matrix.os}}
+
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Install packages
+        if: matrix.install
+        run: sudo apt install ${{matrix.install}}
+
+      - name: Setup Boost
+        run: |
+          echo GITHUB_REPOSITORY: $GITHUB_REPOSITORY
+          LIBRARY=${GITHUB_REPOSITORY#*/}
+          echo LIBRARY: $LIBRARY
+          echo "LIBRARY=$LIBRARY" >> $GITHUB_ENV
+          echo GITHUB_BASE_REF: $GITHUB_BASE_REF
+          echo GITHUB_REF: $GITHUB_REF
+          REF=${GITHUB_BASE_REF:-$GITHUB_REF}
+          REF=${REF#refs/heads/}
+          echo REF: $REF
+          BOOST_BRANCH=develop && [ "$REF" == "master" ] && BOOST_BRANCH=master || true
+          echo BOOST_BRANCH: $BOOST_BRANCH
+          cd ..
+          git clone -b $BOOST_BRANCH --depth 10 https://github.com/boostorg/boost.git boost-root
+          cd boost-root
+          git submodule update --init --depth 10 --jobs 2 tools/boostdep tools/inspect libs/filesystem
+          python tools/boostdep/depinst/depinst.py --git_args "--depth 10 --jobs 3" filesystem
+          rm -rf libs/$LIBRARY/*
+          cp -r $GITHUB_WORKSPACE/* libs/$LIBRARY
+          python tools/boostdep/depinst/depinst.py --include benchmark --include example --include examples --include tools --git_args "--depth 10 --jobs 3" $LIBRARY
+          ./bootstrap.sh
+          ./b2 -j4 variant=debug tools/inspect
+
+      - name: Run CMake tests
+        if: ${{matrix.toolset == 'gcc-14'}}
+        run: |
+          cd ../boost-root/
+          mkdir __build
+          cd __build
+          cmake -DBUILD_TESTING=1 -DBOOST_INCLUDE_LIBRARIES=conversion -DCMAKE_CXX_COMPILER=g++-14 -DCMAKE_C_COMPILER=gcc-14 ..
+          cmake --build . --target tests
+          ctest --output-on-failure --no-tests=error
+          cd ..
+          rm -rf __build
+
+      - name: Run tests
+        run: |
+          cd ../boost-root
+          ./b2 -j3 libs/$LIBRARY/test toolset=${{matrix.toolset}} cxxstd=${{matrix.cxxstd}} variant=debug,release "${{matrix.cxxflags}}" "${{matrix.linkflags}}" "${{matrix.launcher}}"
+          dist/bin/inspect libs/$LIBRARY
+
+      - name: Prepare coverage data
+        if: matrix.gcov_tool
+        run: |
+          mkdir -p $GITHUB_WORKSPACE/coveralls
+
+          echo -e "#!/bin/bash\nexec ${{matrix.gcov_tool}} \"\$@\"" > $GITHUB_WORKSPACE/coveralls/gcov_wrapper.sh
+          chmod +x $GITHUB_WORKSPACE/coveralls/gcov_wrapper.sh
+          wget https://github.com/linux-test-project/lcov/archive/v1.16.zip
+          unzip v1.16.zip
+          LCOV="`pwd`/lcov-1.16/bin/lcov --gcov-tool $GITHUB_WORKSPACE/coveralls/gcov_wrapper.sh"
+
+          echo "$LCOV --directory ../boost-root/bin.v2/libs/$LIBRARY/ --base-directory `pwd`/libs/$LIBRARY/test --capture --output-file $GITHUB_WORKSPACE/coveralls/coverage.info"
+          $LCOV --directory ../boost-root/bin.v2/libs/$LIBRARY/ --base-directory ../boost-root/ --capture --output-file $GITHUB_WORKSPACE/coveralls/coverage.info
+          $LCOV --remove $GITHUB_WORKSPACE/coveralls/coverage.info "/usr*" "*/$LIBRARY/test/*" ${{matrix.ignore_coverage}} "*/$LIBRARY/tests/*" "*/$LIBRARY/examples/*" "*/$LIBRARY/example/*" -o $GITHUB_WORKSPACE/coveralls/coverage.info
+
+          cd ../boost-root
+          OTHER_LIBS=`grep "submodule .*" .gitmodules | sed 's/\[submodule\ "\(.*\)"\]/"\*\/boost\/\1\.hpp" "\*\/boost\/\1\/\*"/g'| sed "/\"\*\/boost\/$LIBRARY\/\*\"/d" | sed ':a;N;$!ba;s/\n/ /g'`
+          echo $OTHER_LIBS
+          eval "$LCOV --remove $GITHUB_WORKSPACE/coveralls/coverage.info $OTHER_LIBS -o $GITHUB_WORKSPACE/coveralls/coverage.info"
+
+      - name: Coveralls
+        uses: coverallsapp/github-action@master
+        if: matrix.gcov_tool
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          path-to-lcov: ./coveralls/coverage.info
+          parallel: true
+
+  windows:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - toolset: msvc-14.3
+            cxxstd: "14,17,latest"
+            addrmd: 32,64
+            os: windows-2025
+          - toolset: gcc
+            cxxstd: "03,11,14,17,2a"
+            addrmd: 64
+            os: windows-2025
+
+    runs-on: ${{matrix.os}}
+
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Setup Boost
+        shell: cmd
+        run: |
+          echo GITHUB_REPOSITORY: %GITHUB_REPOSITORY%
+          for /f %%i in ("%GITHUB_REPOSITORY%") do set LIBRARY=%%~nxi
+          echo LIBRARY: %LIBRARY%
+          echo LIBRARY=%LIBRARY%>>%GITHUB_ENV%
+          echo GITHUB_BASE_REF: %GITHUB_BASE_REF%
+          echo GITHUB_REF: %GITHUB_REF%
+          if "%GITHUB_BASE_REF%" == "" set GITHUB_BASE_REF=%GITHUB_REF%
+          set BOOST_BRANCH=develop
+          for /f %%i in ("%GITHUB_BASE_REF%") do if "%%~nxi" == "master" set BOOST_BRANCH=master
+          echo BOOST_BRANCH: %BOOST_BRANCH%
+          cd ..
+          git clone -b %BOOST_BRANCH% --depth 10 https://github.com/boostorg/boost.git boost-root
+          cd boost-root
+          xcopy /s /e /q %GITHUB_WORKSPACE% libs\%LIBRARY%\
+          git submodule update --init tools/boostdep
+          python tools/boostdep/depinst/depinst.py --include benchmark --include example --include examples --include tools --git_args "--jobs 3" %LIBRARY%
+          cmd /c bootstrap
+
+      - name: Run CMake tests
+        if: ${{matrix.toolset == 'msvc-14.3'}}
+        shell: cmd
+        run: |
+          choco install --no-progress ninja
+          call "C:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Auxiliary/Build/vcvarsall.bat" x64
+          cd ../boost-root/
+          mkdir __build
+          cd __build
+          cmake -DBUILD_TESTING=1 -DBOOST_INCLUDE_LIBRARIES=conversion ..
+          cmake --build . --target tests --config Debug
+          ctest --output-on-failure --no-tests=error -C Debug
+          cd ..
+          rm -rf __build
+
+      - name: Run tests
+        shell: cmd
+        run: |
+          cd ../boost-root
+          b2 -j3 libs/%LIBRARY%/test toolset=${{matrix.toolset}} cxxstd=${{matrix.cxxstd}} address-model=${{matrix.addrmd}} variant=debug,release
+
+  finish:
+    needs: posix
+    runs-on: ubuntu-latest
+    steps:
+    - name: Coveralls Finished
+      uses: coverallsapp/github-action@master
+      with:
+        github-token: ${{ secrets.github_token }}
+        parallel-finished: true

.travis.yml

@@ -1,119 +0,0 @@
-# Use, modification, and distribution are
-# subject to the Boost Software License, Version 1.0. (See accompanying
-# file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-#
-# Copyright Antony Polukhin 2014-2016.
-
-#
-# See https://svn.boost.org/trac/boost/wiki/TravisCoverals for description of this file
-# and how it can be used with Boost libraries.
-#
-# File revision #7
-
-sudo: false
-language: cpp
-compiler:
-    - gcc
-#    - clang
-
-os:
-    - linux
-
-env:
-    global:
-        # Autodetect Boost branch by using the following code: - BRANCH_TO_TEST=$TRAVIS_BRANCH
-        # or just directly specify it
-        - BRANCH_TO_TEST=$TRAVIS_BRANCH
-
-        # Files, which coverage results must be ignored (files from other projects).
-        # Example: - IGNORE_COVERAGE='*/boost/progress.hpp */filesystem/src/*'
-        - IGNORE_COVERAGE=''
-
-        # Explicitly remove the following library from Boost. This may be usefull, if you're for example running Travis
-        # from `Boost.DLL` repo, while Boost already has `dll`.
-        #
-        # By default is eaual to - BOOST_REMOVE=$(basename $TRAVIS_BUILD_DIR)
-        # This will force to use local repo content, instead of the Boost's default.
-        - BOOST_REMOVE=$(basename $TRAVIS_BUILD_DIR)
-
-    matrix:
-        # Note that "--coverage -fsanitize=address,leak,undefined -DBOOST_TRAVISCI_BUILD" are added automatically lower in code
-        - CXX_FLAGS="-std=c++98" LINK_FLAGS="" TOOLSET=gcc-6
-        - CXX_FLAGS="-std=c++11" LINK_FLAGS="" TOOLSET=gcc-6
-        - CXX_FLAGS="-std=c++1y" LINK_FLAGS="" TOOLSET=gcc-6
-        #- CXX_FLAGS="-std=c++11 -stdlib=libc++" LINK_FLAGS="-stdlib=libc++" TOOLSET=clang
-        #- CXX_FLAGS="-std=c++1y -stdlib=libc++" LINK_FLAGS="-stdlib=libc++" TOOLSET=clang
-
-###############################################################################################################
-# From this point and below code is same for all the Boost libs
-###############################################################################################################
-
-
-# Installing additional tools
-addons:
-  apt:
-    sources:
-    - ubuntu-toolchain-r-test
-    - git-core
-    packages:
-    - git
-    - python-yaml
-    - gcc-6
-    - g++-6
-    - clang
-    - libc++-dev
-
-before_install:
-    # Set this to the name of the library
-    - PROJECT_TO_TEST=`basename $TRAVIS_BUILD_DIR`
-    # Cloning Boost libraries (fast nondeep cloning)
-    - BOOST=$HOME/boost-local
-    - echo "Testing $PROJECT_TO_TEST, to remove $BOOST/libs/$BOOST_REMOVE, testing branch $BRANCH_TO_TEST"
-    - git init $BOOST
-    - cd $BOOST
-    - git remote add --no-tags -t $BRANCH_TO_TEST origin https://github.com/boostorg/boost.git
-    - git fetch --depth=1
-    - git checkout $BRANCH_TO_TEST
-    - git submodule update --jobs=3 --init --merge
-    - git remote set-branches --add origin $BRANCH_TO_TEST
-    - git pull --recurse-submodules
-    - git status
-    - rm -rf $BOOST/libs/$BOOST_REMOVE
-    - mv $TRAVIS_BUILD_DIR $BOOST/libs/$PROJECT_TO_TEST
-    - TRAVIS_BUILD_DIR=$BOOST/libs/$PROJECT_TO_TEST
-    - ./bootstrap.sh
-    - ./b2 headers
-    - cd $BOOST/libs/$PROJECT_TO_TEST/test/
-
-script:
-    # `--coverage` flags required to generate coverage info for Coveralls
-    - ../../../b2 "testing.launcher=LD_PRELOAD=/usr/lib/x86_64-linux-gnu/libasan.so.3 " address-model=64 architecture=x86 toolset=$TOOLSET cxxflags="--coverage -fsanitize=address,leak,undefined -DBOOST_TRAVISCI_BUILD $CXX_FLAGS" linkflags="$LINK_FLAGS --coverage -lasan -lubsan"
-
-after_success:
-    # Copying Coveralls data to a separate folder
-    - mkdir -p $TRAVIS_BUILD_DIR/coverals
-    - find ../../../bin.v2/ -name "*.gcda" -exec cp "{}" $TRAVIS_BUILD_DIR/coverals/ \;
-    - find ../../../bin.v2/ -name "*.gcno" -exec cp "{}" $TRAVIS_BUILD_DIR/coverals/ \;
-    - find ../../../bin.v2/ -name "*.da" -exec cp "{}" $TRAVIS_BUILD_DIR/coverals/ \;
-    - find ../../../bin.v2/ -name "*.no" -exec cp "{}" $TRAVIS_BUILD_DIR/coverals/ \;
-    - wget https://github.com/linux-test-project/lcov/archive/v1.12.zip
-    - unzip v1.12.zip
-    - LCOV="`pwd`/lcov-1.12/bin/lcov --gcov-tool gcov-6"
-
-    # Preparing Coveralls data by changind data format to a readable one
-    - echo "$LCOV --directory $TRAVIS_BUILD_DIR/coverals --base-directory `pwd` --capture --output-file $TRAVIS_BUILD_DIR/coverals/coverage.info"
-    - $LCOV --directory $TRAVIS_BUILD_DIR/coverals --base-directory `pwd` --capture --output-file $TRAVIS_BUILD_DIR/coverals/coverage.info
-
-    # ... erasing /test/ /example/ folder data
-    - cd $BOOST
-    - $LCOV --remove $TRAVIS_BUILD_DIR/coverals/coverage.info "/usr*" "*/$PROJECT_TO_TEST/test/*" $IGNORE_COVERAGE "*/$PROJECT_TO_TEST/tests/*" "*/$PROJECT_TO_TEST/examples/*" "*/$PROJECT_TO_TEST/example/*" -o $TRAVIS_BUILD_DIR/coverals/coverage.info
-
-    # ... erasing data that is not related to this project directly
-    - OTHER_LIBS=`grep "submodule .*" .gitmodules | sed 's/\[submodule\ "\(.*\)"\]/"\*\/boost\/\1\.hpp" "\*\/boost\/\1\/\*"/g'| sed "/\"\*\/boost\/$PROJECT_TO_TEST\/\*\"/d" | sed ':a;N;$!ba;s/\n/ /g'`
-    - echo $OTHER_LIBS
-    - eval "$LCOV --remove $TRAVIS_BUILD_DIR/coverals/coverage.info $OTHER_LIBS -o $TRAVIS_BUILD_DIR/coverals/coverage.info"
-
-    # Sending data to Coveralls
-    - cd $TRAVIS_BUILD_DIR
-    - gem install coveralls-lcov
-    - coveralls-lcov coverals/coverage.info

CMakeLists.txt

@@ -0,0 +1,22 @@
+# Copyright 2019 Mike Dev
+# Distributed under the Boost Software License, Version 1.0.
+# See accompanying file LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt
+
+cmake_minimum_required( VERSION 3.5...4.20 )
+project( boost_conversion VERSION "${BOOST_SUPERPROJECT_VERSION}" LANGUAGES CXX )
+
+add_library( boost_conversion INTERFACE )
+add_library( Boost::conversion ALIAS boost_conversion )
+
+target_include_directories( boost_conversion INTERFACE include )
+
+target_link_libraries( boost_conversion
+    INTERFACE
+        Boost::assert
+        Boost::config
+        Boost::throw_exception
+)
+
+if(BUILD_TESTING)
+  add_subdirectory(test)
+endif()

README.md

@@ -1,16 +1,15 @@
-#[Boost.Conversion](http://boost.org/libs/conversion)
+# [Boost.Conversion](https://boost.org/libs/conversion)
-Boost.Conversion is one of the [Boost C++ Libraries](http://github.com/boostorg). This library improves program safety and clarity by performing otherwise messy conversions. 
+Boost.Conversion is one of the [Boost C++ Libraries](https://github.com/boostorg). This library improves program safety and clarity by performing otherwise messy conversions. 
 
 ### Test results
 
 @               | Build         | Tests coverage | More info
 ----------------|-------------- | -------------- |-----------
-Develop branch: | [![Build Status](https://travis-ci.org/apolukhin/conversion.svg?branch=develop)](https://travis-ci.org/apolukhin/conversion) [![Build status](https://ci.appveyor.com/api/projects/status/yep84179w535pppg/branch/develop?svg=true)](https://ci.appveyor.com/project/apolukhin/conversion/branch/develop) | [![Coverage Status](https://coveralls.io/repos/apolukhin/conversion/badge.png?branch=develop)](https://coveralls.io/r/apolukhin/conversion?branch=develop) | [details...](http://www.boost.org/development/tests/develop/developer/conversion.html)
+Develop branch: | [![CI](https://github.com/boostorg/conversion/actions/workflows/ci.yml/badge.svg?branch=develop)](https://github.com/boostorg/conversion/actions/workflows/ci.yml) [![Build status](https://ci.appveyor.com/api/projects/status/1cky1hrunfa46bdx/branch/develop?svg=true)](https://ci.appveyor.com/project/apolukhin/conversion/branch/develop) | [![Coverage Status](https://coveralls.io/repos/github/boostorg/conversion/badge.svg?branch=develop)](https://coveralls.io/github/boostorg/conversion?branch=develop) | [details...](https://regression.boost.io/develop/developer/conversion.html)
-Master branch:  | [![Build Status](https://travis-ci.org/apolukhin/conversion.svg?branch=master)](https://travis-ci.org/apolukhin/conversion) [![Build status](https://ci.appveyor.com/api/projects/status/yep84179w535pppg/branch/master?svg=true)](https://ci.appveyor.com/project/apolukhin/conversion/branch/master) | [![Coverage Status](https://coveralls.io/repos/apolukhin/conversion/badge.png?branch=master)](https://coveralls.io/r/apolukhin/conversion?branch=master) | [details...](http://www.boost.org/development/tests/master/developer/conversion.html)
+Master branch:  | [![CI](https://github.com/boostorg/conversion/actions/workflows/ci.yml/badge.svg?branch=master)](https://github.com/boostorg/conversion/actions/workflows/ci.yml) [![Build status](https://ci.appveyor.com/api/projects/status/1cky1hrunfa46bdx/branch/master?svg=true)](https://ci.appveyor.com/project/apolukhin/conversion/branch/master) | [![Coverage Status](https://coveralls.io/repos/github/boostorg/conversion/badge.svg?branch=master)](https://coveralls.io/github/boostorg/conversion?branch=master) | [details...](https://regression.boost.io/master/developer/conversion.html)
 
-
+[Latest developer documentation](https://www.boost.org/doc/libs/develop/doc/html/conversion.html)
-[Open Issues](https://svn.boost.org/trac/boost/query?status=!closed&component=conversion&or&status=!closed&component=lexical_cast)
 
 ### License
 
-Distributed under the [Boost Software License, Version 1.0](http://boost.org/LICENSE_1_0.txt).
+Distributed under the [Boost Software License, Version 1.0](https://boost.org/LICENSE_1_0.txt).

build.jam

@@ -0,0 +1,25 @@
+# Copyright René Ferdinand Rivera Morell 2023-2024
+# 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)
+
+require-b2 5.2 ;
+
+constant boost_dependencies :
+    /boost/assert//boost_assert
+    /boost/config//boost_config
+    /boost/throw_exception//boost_throw_exception ;
+
+project /boost/conversion
+    : common-requirements
+        <include>include
+    ;
+
+explicit
+    [ alias boost_conversion : : : : <library>$(boost_dependencies) ]
+    [ alias all : boost_conversion test ]
+    ;
+
+call-if : boost-library conversion
+    ;
+

doc/conversion.qbk

@@ -1,5 +1,7 @@
 [/
     Copyright 2016 Mikhail Maximov.
+    Copyright Antony Polukhin, 2020-2026.
+
     Distributed under the Boost Software License, Version 1.0. (See accompanying
     file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</a>)
 ]
@@ -8,15 +10,15 @@
     [quickbook 1.6]
     [compatibility-mode 1.5]
     [id conversion]
-    [version 1.6]
+    [version 1.7]
     [authors [Stroustrup, Bjarne], [Abrahams, Dave], [Rasin, Boris], [Polukhin, Antony]]
-    [copyright 2001 Beman Dawes]
+    [copyright 2001 Beman Dawes, 2014-2026 Antony Polukhin]
     [license
         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])
     ]
-    [source-mode teletype]
+    [source-mode c++]
 ]
 
 [/ QuickBook Document version 1.5 ]
@@ -28,8 +30,7 @@ The Conversion Library improves program safety and clarity by performing
 otherwise messy conversions. It includes cast-style function templates designed 
 to complement the C++ Standard's built-in casts.
 
-To reduce coupling, particularly to standard library IOStreams, 
+To reduce coupling, the Boost Conversion Library is supplied by several headers:
-the Boost Conversion Library is supplied by several headers:
 
 # The [@boost:boost/polymorphic_cast.hpp boost/polymorphic_cast.hpp] header
   provides [link polymorphic_cast `polymorphic_cast<>`] and
@@ -40,11 +41,9 @@ the Boost Conversion Library is supplied by several headers:
   [link polymorphic_pointer_cast `polymorphic_pointer_downcast<>`]
 # The [@boost:boost/implicit_cast.hpp boost/implicit_cast.hpp] header provides `implicit_cast<>` 
   to perform implicit casts only (no down-cast, no void*->T*, no U->T if T has only explicit constructors for U).
-# The [@boost:boost/lexical_cast.hpp boost/lexical_cast.hpp] header 
-  provides [@boost:libs/lexical_cast/doc/html/index.html `lexical_cast<>`] general literal text conversions, such as an `int` represented as a `string`, or vice-versa. 
 
 [endsect]
-  
+
 [section Polymorphic casts]
 Pointers to polymorphic objects (objects of classes which define at
 least one virtual function) are sometimes downcast or crosscast.
@@ -58,6 +57,7 @@ safety, suffer poor readability, and are difficult to locate with search
 tools.
 
 [#polymorphic_downcast]
+[section polymorphic_downcast]
 
 The C++ built-in `static_cast` can be used for efficiently
 downcasting pointers to polymorphic objects, but provides no error
@@ -68,11 +68,11 @@ debug compilations adds safety via an `assert()` that a `dynamic_cast`
 succeeds.
 
 A `polymorphic_downcast` should be used for
-downcasts that you are certain should succeed.  Error checking is
+downcasts that you are certain should succeed. Error checking is
 only performed in translation units where `NDEBUG` is
 not defined, via
 ```
-	assert( dynamic_cast<Derived>(x) == x )
+    assert( dynamic_cast<Derived>(x) == x )
 ```
 where `x` is the source pointer.  This approach
 ensures that not only is a non-zero pointer returned, but also
@@ -81,17 +81,33 @@ Attempts to crosscast using `polymorphic_downcast` will
 fail to compile.
 
 [warning Because `polymorphic_downcast` uses `assert()`, it
-violates the One Definition Rule (ODR) if NDEBUG is inconsistently
+violates the One Definition Rule (ODR) if `NDEBUG` is inconsistently
 defined across translation units. See ISO Std 3.2]
 
+[h4 Example:]
+```
+    #include <boost/polymorphic_cast.hpp>
+    ...
+    class Fruit { public: virtual ~Fruit(){}; ... };
+    class Banana : public Fruit { ... };
+    ...
+    void f( Fruit * fruit ) {
+      // ... logic which leads us to believe it is a Banana
+      Banana * banana = boost::polymorphic_downcast<Banana*>(fruit);
+      ...
+    }
+```
+[endsect]
+
 [#polymorphic_cast]
+[section polymorphic_cast]
 
 The C++ built-in `dynamic_cast` can be used for downcasts and
 crosscasts of pointers to polymorphic objects, but error notification in
 the form of a returned value of 0 is inconvenient to test, or worse yet,
 easy to forget to test. The throwing form of `dynamic_cast`, which
 works on references, can be used on pointers through the ugly expression
-`&dynamic_cast<T&>(*p), which causes undefined 
+`&dynamic_cast<T&>(*p)`, which causes undefined
 behavior if `p` is `0`. The `polymorphic_cast`
 template performs a `dynamic_cast` on a pointer, and throws an
 exception if the `dynamic_cast` returns 0.
@@ -99,91 +115,91 @@ exception if the `dynamic_cast` returns 0.
 For crosscasts, or when the success of a cast can only be known at runtime, 
 or when efficiency is not important, `polymorphic_cast` is preferred.
 
-The C++ built-in dynamic_cast must be used to cast references rather than pointers.
+The C++ built-in `dynamic_cast` must be used to cast references rather than pointers.
 It is also the only cast that can be used to check whether a given interface is supported; in that case a return of 0 isn't an error condition.
 
+[endsect]
+
+
 [#polymorphic_pointer_cast]
-While polymorphic_downcast and polymorphic_cast work with built-in pointer types only,
+[section polymorphic_pointer_cast]
-polymorphic_pointer_downcast and polymorphic_pointer_cast are more generic versions
+While `polymorphic_downcast` and `polymorphic_cast` work with built-in pointer types only,
+`polymorphic_pointer_downcast` and `polymorphic_pointer_cast` are more generic versions
 with support for any pointer type for which the following expressions would be valid:
 
 For `polymorphic_pointer_downcast`:
 ```
-	static_pointer_cast<Derived>(p);
+    static_pointer_cast<Derived>(p);
-	dynamic_pointer_cast<Derived>(p);
+    dynamic_pointer_cast<Derived>(p);
 ```
 For `polymorphic_pointer_cast`:
 ```
-	dynamic_pointer_cast<Derived>(p);
+    dynamic_pointer_cast<Derived>(p);
-	!p; // conversion to bool with negation
+    !p; // conversion to bool with negation
 ```
 
 This includes C++ built-in pointers, `std::shared_ptr`,
 `boost::shared_ptr`, `boost::intrusive_ptr`, etc.
 
-[endsect]
+
-[section `polymorphic_cast`, `polymorphic_downcast`, `polymorphic_pointer_cast` and `polymorphic_pointer_downcast` synopsis]
+[h4 Example:]
 ```
-	namespace boost {
+    #include <boost/polymorphic_pointer_cast.hpp>
 
-	template <class Derived, class Base>
+    class Fruit { public: virtual ~Fruit(){} };
-	inline Derived polymorphic_cast(Base* x);
+    class Banana : public Fruit {};
-	// Throws: std::bad_cast if ( dynamic_cast<Derived>(x) == 0 )
-	// Returns: dynamic_cast<Derived>(x)
 
-	template <class Derived, class Base>
+    // Use one of these:
-	inline Derived polymorphic_downcast(Base* x);
+    using FruitPtr = Fruit*;
-	// Effects: assert( dynamic_cast<Derived>(x) == x );
+    using FruitPtr = std::shared_ptr<Fruit>;
-	// Returns: static_cast<Derived>(x)
+    using FruitPtr = boost::shared_ptr<Fruit>;
+    using FruitPtr = boost::intrusive_ptr<Fruit>;
 
-	template <class Derived, class Base>
+    void f(FruitPtr fruit) {
-	inline auto polymorphic_pointer_cast(Base x);
+      // ... logic which leads us to believe it is a banana
-	// Throws: std::bad_cast if ( dynamic_pointer_cast<Derived>(x) == 0 )
+      auto banana = boost::polymorphic_pointer_downcast<Banana>(fruit);
-	// Returns: dynamic_pointer_cast<Derived>(x)
+      ...
+    }
+```
 
-	template <class Derived, class Base>
+[endsect]
-	inline auto polymorphic_pointer_downcast(Base x);
-	// Effects: assert( dynamic_pointer_cast<Derived>(x) == x );
-	// Returns: static_pointer_cast<Derived>(x)
 
-	}
+[endsect]
+
+[section Synopsis]
+```
+    namespace boost {
+
+    // Throws: std::bad_cast if ( dynamic_cast<Derived>(x) == 0 )
+    // Returns: dynamic_cast<Derived>(x)
+    template <class Derived, class Base>
+    constexpr Derived polymorphic_cast(Base* x);
+
+    // Effects: assert( dynamic_cast<Derived>(x) == x );
+    // Returns: static_cast<Derived>(x)
+    template <class Derived, class Base>
+    constexpr Derived polymorphic_downcast(Base* x);
+
+    // Effects: assert( dynamic_cast<Derived>(&x) == &x );
+    // Returns: static_cast<Derived>(x)
+    template <class Derived, class Base>
+    constexpr Derived polymorphic_downcast(Base& x);
+
+    // Throws: std::bad_cast if ( dynamic_pointer_cast<Derived>(x) == 0 )
+    // Returns: dynamic_pointer_cast<Derived>(x)
+    template <class Derived, class Base>
+    inline auto polymorphic_pointer_cast(Base x);
+
+    // Effects: assert( dynamic_pointer_cast<Derived>(x) == x );
+    // Returns: static_pointer_cast<Derived>(x)
+    template <class Derived, class Base>
+    inline auto polymorphic_pointer_downcast(Base x);
+
+    }
 ```
 [endsect]
-[section `polymorphic_downcast` example]
-```
-	#include <boost/polymorphic_cast.hpp>
-	...
-	class Fruit { public: virtual ~Fruit(){}; ... };
-	class Banana : public Fruit { ... };
-	...
-	void f( Fruit * fruit ) {
-	  // ... logic which leads us to believe it is a Banana
-	  Banana * banana = boost::polymorphic_downcast<Banana*>(fruit);
-	  ...
-	}
-```
-[endsect]
-[section `polymorphic_pointer_downcast` example]
-```
-	#include <boost/polymorphic_pointer_cast.hpp>
 
-	class Fruit { public: virtual ~Fruit(){} };
-	class Banana : public Fruit {};
 
-	// use one of these:
-
-	typedef Fruit* FruitPtr;
-	typedef std::shared_ptr<Fruit> FruitPtr;
-	typedef boost::shared_ptr<Fruit> FruitPtr;
-	typedef boost::intrusive_ptr<Fruit> FruitPtr;
-
-	void f(FruitPtr fruit) {
-	  // ... logic which leads us to believe it is a banana
-	  auto banana = boost::polymorphic_pointer_downcast<Banana>(fruit);
-	  ...
-	}
-```
-[endsect]
 [section History]
 `polymorphic_cast` was suggested by Bjarne Stroustrup in "The C++ Programming Language".
 
@@ -192,6 +208,8 @@ This includes C++ built-in pointers, `std::shared_ptr`,
 `polymorphic_pointer_downcast` was contributed by [@http://www.boost.org/people/boris_rasin.htm Boris Rasin]
 and `polymorphic_pointer_cast` by Antony Polukhin.
 
-An old numeric_cast that was contributed by [@http://www.boost.org/people/kevlin_henney.htm Kevlin Henney]
+`polymorphic_downcast` overload for references was contributed by Julien Delacroix.
-is now superseeded by the [@boost:numeric_conversion/doc/html/html/boost_numericconversion/improved_numeric_cast__.html Boost Numeric Conversion Library]
+
+An old `numeric_cast` that was contributed by [@http://www.boost.org/people/kevlin_henney.htm Kevlin Henney]
+is now superseded by the [@boost:numeric_conversion/doc/html/html/boost_numericconversion/improved_numeric_cast__.html Boost Numeric Conversion Library]
 [endsect]

include/boost/implicit_cast.hpp

@@ -2,8 +2,14 @@
 // Distributed under the Boost Software License, Version 1.0. (See
 // accompanying file LICENSE_1_0.txt or copy at
 // http://www.boost.org/LICENSE_1_0.txt)
-#ifndef IMPLICIT_CAST_DWA200356_HPP
+
-# define IMPLICIT_CAST_DWA200356_HPP
+#ifndef BOOST_IMPLICIT_CAST_DWA200356_HPP
+#define BOOST_IMPLICIT_CAST_DWA200356_HPP
+
+#include <boost/config.hpp>
+#ifdef BOOST_HAS_PRAGMA_ONCE
+# pragma once
+#endif
 
 namespace boost {
 
@@ -11,7 +17,7 @@ namespace detail {
 
 template<class T> struct icast_identity
 {
-    typedef T type;
+    using type = T;
 };
 
 } // namespace detail
@@ -22,15 +28,11 @@ template<class T> struct icast_identity
 // The use of identity creates a non-deduced form, so that the
 // explicit template argument must be supplied
 template <typename T>
-inline T implicit_cast (typename boost::detail::icast_identity<T>::type x) {
+constexpr T implicit_cast (typename boost::detail::icast_identity<T>::type x) {
     return x;
 }
 
-// incomplete return type now is here
-//template <typename T>
-//void implicit_cast (...);
-
 } // namespace boost
 
 
-#endif // IMPLICIT_CAST_DWA200356_HPP
+#endif // BOOST_IMPLICIT_CAST_DWA200356_HPP

include/boost/polymorphic_cast.hpp

@@ -14,7 +14,7 @@
 //  08 Nov 14  Add polymorphic_pointer_downcast (Boris Rasin)
 //  09 Jun 14  "cast.hpp" was renamed to "polymorphic_cast.hpp" and
 //             inclusion of numeric_cast was removed (Antony Polukhin)
-//  23 Jun 05  numeric_cast removed and redirected to the new verion (Fernando Cacciola)
+//  23 Jun 05  numeric_cast removed and redirected to the new version (Fernando Cacciola)
 //  02 Apr 01  Removed BOOST_NO_LIMITS workarounds and included
 //             <boost/limits.hpp> instead (the workaround did not
 //             actually compile when BOOST_NO_LIMITS was defined in
@@ -31,7 +31,7 @@
 //  19 Oct 00  Fix numeric_cast for floating-point types (Dave Abrahams)
 //  15 Jul 00  Suppress numeric_cast warnings for GCC, Borland and MSVC
 //             (Dave Abrahams)
-//  30 Jun 00  More MSVC6 wordarounds.  See comments below.  (Dave Abrahams)
+//  30 Jun 00  More MSVC6 workarounds.  See comments below.  (Dave Abrahams)
 //  28 Jun 00  Removed implicit_cast<>.  See comment below. (Beman Dawes)
 //  27 Jun 00  More MSVC6 workarounds
 //  15 Jun 00  Add workarounds for MSVC6
@@ -49,15 +49,25 @@
 #ifndef BOOST_POLYMORPHIC_CAST_HPP
 #define BOOST_POLYMORPHIC_CAST_HPP
 
-# include <boost/config.hpp>
+#include <boost/config.hpp>
-# include <boost/assert.hpp>
-# include <boost/throw_exception.hpp>
-# include <typeinfo>
 
 #ifdef BOOST_HAS_PRAGMA_ONCE
 #   pragma once
 #endif
 
+# include <boost/assert.hpp>
+# include <boost/throw_exception.hpp>
+
+# include <memory>  // std::addressof
+# include <typeinfo>
+# include <type_traits>
+
+#if defined(__cpp_constexpr) && __cpp_constexpr >= 201907L
+#define BOOST_CONVERSION_IMPL_CONSTEXPR_DYN_CAST constexpr
+#else
+#define BOOST_CONVERSION_IMPL_CONSTEXPR_DYN_CAST inline
+#endif
+
 namespace boost
 {
 //  See the documentation for descriptions of how to choose between
@@ -70,7 +80,7 @@ namespace boost
     //  section 15.8 exercise 1, page 425.
 
     template <class Target, class Source>
-    inline Target polymorphic_cast(Source* x)
+    BOOST_CONVERSION_IMPL_CONSTEXPR_DYN_CAST Target polymorphic_cast(Source* x)
     {
         Target tmp = dynamic_cast<Target>(x);
         if ( tmp == 0 ) boost::throw_exception( std::bad_cast() );
@@ -79,7 +89,7 @@ namespace boost
 
 //  polymorphic_downcast  ----------------------------------------------------//
 
-    //  BOOST_ASSERT() checked polymorphic downcast.  Crosscasts prohibited.
+    //  BOOST_ASSERT() checked raw pointer polymorphic downcast.  Crosscasts prohibited.
 
     //  WARNING: Because this cast uses BOOST_ASSERT(), it violates
     //  the One Definition Rule if used in multiple translation units
@@ -89,12 +99,34 @@ namespace boost
     //  Contributed by Dave Abrahams
 
     template <class Target, class Source>
-    inline Target polymorphic_downcast(Source* x)
+    BOOST_CONVERSION_IMPL_CONSTEXPR_DYN_CAST Target polymorphic_downcast(Source* x)
     {
         BOOST_ASSERT( dynamic_cast<Target>(x) == x );  // detect logic error
         return static_cast<Target>(x);
     }
 
+    //  BOOST_ASSERT() checked reference polymorphic downcast.  Crosscasts prohibited.
+
+    //  WARNING: Because this cast uses BOOST_ASSERT(), it violates
+    //  the One Definition Rule if used in multiple translation units
+    //  where BOOST_DISABLE_ASSERTS, BOOST_ENABLE_ASSERT_HANDLER
+    //  NDEBUG are defined inconsistently.
+
+    //  Contributed by Julien Delacroix
+
+    template <class Target, class Source>
+    BOOST_CONVERSION_IMPL_CONSTEXPR_DYN_CAST typename std::enable_if<
+        std::is_reference<Target>::value, Target
+    >::type polymorphic_downcast(Source& x)
+    {
+        using target_pointer_type = typename std::remove_reference<Target>::type*;
+        return *boost::polymorphic_downcast<target_pointer_type>(
+            std::addressof(x)
+        );
+    }
+
 } // namespace boost
 
+#undef BOOST_CONVERSION_IMPL_CONSTEXPR_DYN_CAST
+
 #endif  // BOOST_POLYMORPHIC_CAST_HPP

include/boost/polymorphic_pointer_cast.hpp

@@ -1,5 +1,6 @@
 //  boost polymorphic_pointer_cast.hpp header file  ----------------------------------------------//
-//  (C) Copyright Boris Rasin and Antony Polukhin 2014-2015.
+//  (C) Copyright Boris Rasin, 2014-2021.
+//  (C) Copyright Antony Polukhin, 2014-2026.
 //  Distributed under the Boost
 //  Software License, Version 1.0. (See accompanying file
 //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
@@ -9,19 +10,16 @@
 #ifndef BOOST_CONVERSION_POLYMORPHIC_POINTER_CAST_HPP
 #define BOOST_CONVERSION_POLYMORPHIC_POINTER_CAST_HPP
 
-# include <boost/config.hpp>
+#include <boost/config.hpp>
-# include <boost/assert.hpp>
-# include <boost/pointer_cast.hpp>
-# include <boost/throw_exception.hpp>
-# include <boost/utility/declval.hpp>
-# ifdef BOOST_NO_CXX11_DECLTYPE
-#   include <boost/typeof/typeof.hpp>
-# endif
-
 #ifdef BOOST_HAS_PRAGMA_ONCE
 #   pragma once
 #endif
 
+# include <boost/assert.hpp>
+# include <boost/pointer_cast.hpp>
+# include <boost/throw_exception.hpp>
+
+
 namespace boost
 {
 //  See the documentation for descriptions of how to choose between
@@ -40,36 +38,20 @@ namespace boost
 
     //  Contributed by Boris Rasin
 
-    namespace detail
-    {
-        template <typename Target, typename Source>
-        struct dynamic_pointer_cast_result
-        {
-#ifdef BOOST_NO_CXX11_DECLTYPE
-            BOOST_TYPEOF_NESTED_TYPEDEF_TPL(nested, dynamic_pointer_cast<Target>(boost::declval<Source>()))
-            typedef typename nested::type type;
-#else
-            typedef decltype(dynamic_pointer_cast<Target>(boost::declval<Source>())) type;
-#endif
-        };
-    }
-
     template <typename Target, typename Source>
-    inline typename detail::dynamic_pointer_cast_result<Target, Source>::type
+    inline auto polymorphic_pointer_downcast (const Source& x)
-    polymorphic_pointer_downcast (const Source& x)
+        -> decltype(static_pointer_cast<Target>(x))
     {
         BOOST_ASSERT(dynamic_pointer_cast<Target> (x) == x);
         return static_pointer_cast<Target> (x);
     }
 
     template <typename Target, typename Source>
-    inline typename detail::dynamic_pointer_cast_result<Target, Source>::type
+    inline auto polymorphic_pointer_cast (const Source& x)
-    polymorphic_pointer_cast (const Source& x)
+        -> decltype(dynamic_pointer_cast<Target>(x))
     {
-        typename detail::dynamic_pointer_cast_result<Target, Source>::type tmp
+        auto tmp = dynamic_pointer_cast<Target> (x);
-            = dynamic_pointer_cast<Target> (x);
         if ( !tmp ) boost::throw_exception( std::bad_cast() );
-
         return tmp;
     }
 

index.html

@@ -2,10 +2,14 @@
 <!--
  Copyright (c) 2016 Mikhail Maximov
  vigorous.activity at gmail dot com
- 
+
+ Copyright (c) Antony Polukhin, 2021-2026
+
  Distributed under the Boost Software License,
  Version 1.0. (See accompanying file LICENSE_1_0.txt
  or copy at http://boost.org/LICENSE_1_0.txt)
+
+boost-no-inspect
 -->
 <html>
 <head>
@@ -29,7 +33,7 @@
     <a href="../../doc/html/conversion.html">../../doc/html/conversion.html</a>
   </p>
   <p>
-    &copy; 2014 Antony Polukhin
+    &copy; Antony Polukhin, 2014-2024
   </p>
 </body>
-</html>
+</html>

meta/libraries.json

@@ -11,5 +11,6 @@
     ],
     "maintainers": [
         "Antony Polukhin <antoshkka -at- gmail.com>"
-    ]
+    ],
+    "cxxstd": "11"
 }

test/CMakeLists.txt

@@ -0,0 +1,17 @@
+# Copyright  (c) 2016-2026 Antony Polukhin
+# Distributed under the Boost Software License, Version 1.0.
+# See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt
+
+include(BoostTest OPTIONAL RESULT_VARIABLE HAVE_BOOST_TEST)
+
+if(NOT HAVE_BOOST_TEST)
+  return()
+endif()
+
+set(BOOST_TEST_LINK_LIBRARIES Boost::conversion Boost::core)
+
+boost_test(TYPE run SOURCES cast_test.cpp)
+boost_test(TYPE run SOURCES implicit_cast.cpp)
+boost_test(TYPE compile-fail SOURCES implicit_cast_fail.cpp)
+boost_test(TYPE compile-fail SOURCES implicit_cast_fail2.cpp)
+boost_test(TYPE run SOURCES polymorphic_cast_test.cpp LINK_LIBRARIES Boost::smart_ptr)

test/Jamfile.v2

@@ -1,18 +1,20 @@
 # Copyright (C) 2001-2003 Douglas Gregor
-# Copyright (C) 2011-2014 Antony Polukhin
+# Copyright (C) Antony Polukhin, 2011-2024
 #
 # 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)
 #
 
+require-b2 5.0.1 ;
+import-search /boost/config/checks ;
+import config : requires ;
 import testing ;
 import feature ;
 
 project
     : requirements
-        <toolset>gcc-4.7:<cxxflags>-ftrapv
+        <library>/boost/conversion//boost_conversion
-        <toolset>gcc-4.6:<cxxflags>-ftrapv
+        [ requires cxx11_decltype ]
-        <toolset>clang:<cxxflags>-ftrapv
         # default to all warnings on:
         <warnings>all
         # set warnings as errors for those compilers we know we get warning free:
@@ -24,6 +26,6 @@ test-suite conversion
   : [ run implicit_cast.cpp ]
     [ compile-fail implicit_cast_fail.cpp ]
     [ run cast_test.cpp ]
-    [ run polymorphic_cast_test.cpp ]
+    [ run polymorphic_cast_test.cpp : : : <library>/boost/smart_ptr//boost_smart_ptr ]
     [ compile-fail implicit_cast_fail2.cpp ]
   ;

test/appveyor.yml

@@ -2,23 +2,26 @@
 # subject to the Boost Software License, Version 1.0. (See accompanying
 # file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 #
-# Copyright Antony Polukhin 2016-2017.
+# Copyright Antony Polukhin, 2016-2025.
 
 #
 # See https://svn.boost.org/trac/boost/wiki/TravisCoverals for description of this file
 # and how it can be used with Boost libraries.
 #
-# File revision #3
+# File revision #6
 
 init:
-    - set BRANCH_TO_TEST=%APPVEYOR_REPO_BRANCH%  # Change to branch you wish to test. Use %APPVEYOR_REPO_BRANCH% for current branch.
+    # boost-local/libs/ folder to put this library into. This may be useful, if you're for example running Travis
-    - set BOOST_REMOVE=conversion                # Remove this folder from lib from full clone of Boost. If you are testing `any` repo, write here `any`.
+    # from `Boost.DLL` repo while Boost already has `dll` and with to replace `dll` with content of`Boost.DLL`.
+    #
+    # Otherwise just leave the default value - set BOOST_LIBS_FOLDER=%APPVEYOR_PROJECT_NAME%
+    - set BOOST_LIBS_FOLDER=%APPVEYOR_PROJECT_NAME%
 
 ###############################################################################################################
 # From this point and below code is same for all the Boost libs
 ###############################################################################################################
 
-version: 1.64.{build}-{branch}
+version: 1.84.{build}-{branch}
  
 # branches to build
 branches:
@@ -27,36 +30,56 @@ branches:
 
 skip_tags: true
 
+environment:
+  matrix:
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
+      TOOLSET: msvc-14.1,clang-win
+      CXXSTD: 14,17
+      ADDRMD: 32,64
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      ADDPATH: C:\cygwin\bin;
+      TOOLSET: gcc
+      CXXSTD: 03,11,14,1z
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      ADDPATH: C:\cygwin64\bin;
+      TOOLSET: gcc
+      CXXSTD: 03,11,14,1z
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      ADDPATH: C:\mingw\bin;
+      TOOLSET: gcc
+      CXXSTD: 03,11,14,1z
+    - APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+      ADDPATH: C:\mingw-w64\x86_64-7.2.0-posix-seh-rt_v5-rev1\mingw64\bin;
+      TOOLSET: gcc
+      CXXSTD: 03,11,14,1z
+
 before_build:
-    - set PATH=%PATH%;C:\\MinGW\\bin
+    - set BOOST_BRANCH=develop
-    # Set this to the name of the library
+    - if "%APPVEYOR_REPO_BRANCH%" == "master" set BOOST_BRANCH=master
-    - set PROJECT_TO_TEST=%APPVEYOR_PROJECT_NAME%
+    - echo "Testing %APPVEYOR_PROJECT_NAME%"
-    - echo "Testing %PROJECT_TO_TEST%"
     # Cloning Boost libraries (fast nondeep cloning)
     - set BOOST=C:/boost-local
-    - git init %BOOST%
+    - git clone -b %BOOST_BRANCH% --depth 10 https://github.com/boostorg/boost.git %BOOST%
     - cd %BOOST%
-    - git remote add --no-tags -t %BRANCH_TO_TEST% origin https://github.com/boostorg/boost.git
+    - git submodule update --init --depth 10 tools/build tools/boostdep
-    - git fetch --depth=1
+
-    - git checkout %BRANCH_TO_TEST%
+    - rm -rf %BOOST%/libs/%BOOST_LIBS_FOLDER%
-    - git submodule update --init --merge
+    - mv -f %APPVEYOR_BUILD_FOLDER% %BOOST%/libs/%BOOST_LIBS_FOLDER%
-    - git remote set-branches --add origin %BRANCH_TO_TEST%
+    - python tools/boostdep/depinst/depinst.py --git_args "--depth 10 --jobs 2" %BOOST_LIBS_FOLDER%
-    - git pull --recurse-submodules
-    - git status
-    - rm -rf %BOOST%/libs/%BOOST_REMOVE%
-    - mv %APPVEYOR_BUILD_FOLDER% %BOOST%/libs/%PROJECT_TO_TEST%
-    - set TRAVIS_BUILD_DIR=%BOOST%/libs/%PROJECT_TO_TEST%
 
 build_script:
-    - call "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\vcvarsall.bat" x64
+    - cmd /c bootstrap
-    - bootstrap.bat
     - b2.exe headers
-    - cd %BOOST%/libs/%PROJECT_TO_TEST%/test
+    - cd %BOOST%/libs/%BOOST_LIBS_FOLDER%/test
 
 after_build:
 before_test:
 test_script:
-    - ..\..\..\b2.exe address-model=32 architecture=x86 toolset=msvc,gcc cxxflags="-DBOOST_TRAVISCI_BUILD" -sBOOST_BUILD_PATH=.
+  - PATH=%ADDPATH%%PATH%
+  - if not "%CXXSTD%" == "" set CXXSTD=cxxstd=%CXXSTD%
+  - if not "%ADDRMD%" == "" set ADDRMD=address-model=%ADDRMD%
+  - echo "Running command ..\..\..\b2 -j3 toolset=%TOOLSET% %CXXSTD% %ADDRMD% variant=debug,release"
+  - ..\..\..\b2.exe -j3 toolset=%TOOLSET% %CXXSTD% %ADDRMD% variant=debug,release cxxflags="-DBOOST_TRAVISCI_BUILD"
 
 after_test:
 on_success:

test/cast_test.cpp

@@ -38,6 +38,48 @@ namespace
     };
 }
 
+constexpr bool compile_time_polymorphic_cast_check() {
+#if defined(__cpp_constexpr) && __cpp_constexpr >= 201907L
+    Derived derived;
+    Base* base = &derived;
+    return polymorphic_cast<Derived*>(base) != nullptr;
+#endif
+    return true;
+}
+
+static_assert(
+    compile_time_polymorphic_cast_check(),
+    "polymorphic_cast does not work at compile time"
+);
+
+constexpr bool compile_time_polymorphic_downcast_check() {
+#if defined(__cpp_constexpr) && __cpp_constexpr >= 201907L
+    Derived derived;
+    Base* base = &derived;
+    return polymorphic_downcast<Derived*>(base) != nullptr;
+#endif
+    return true;
+}
+
+static_assert(
+    compile_time_polymorphic_downcast_check(),
+    "polymorphic_downcast does not work at compile time"
+);
+
+constexpr bool compile_time_polymorphic_downcast2_check() {
+#if defined(__cpp_constexpr) && __cpp_constexpr >= 201907L
+    Derived derived;
+    Base& base = derived;
+    Derived& derived_again = polymorphic_downcast<Derived&>(base);
+    (void)derived_again;
+#endif
+    return true;
+}
+
+static_assert(
+    compile_time_polymorphic_downcast2_check(),
+    "polymorphic_downcast does not work at compile time"
+);
 
 int main( int argc, char * argv[] )
 {
@@ -72,7 +114,7 @@ int main( int argc, char * argv[] )
 
     bool caught_exception = false;
     try { derived = polymorphic_cast<Derived*>( base ); }
-    catch (std::bad_cast)
+    catch (const std::bad_cast&)
         { cout<<"caught bad_cast\n"; caught_exception = true; }
     BOOST_TEST( caught_exception );
     //  the following is just so generated code can be inspected

test/implicit_cast.cpp

@@ -4,8 +4,9 @@
 // http://www.boost.org/LICENSE_1_0.txt)
 
 #include <boost/implicit_cast.hpp>
-#include <boost/detail/lightweight_test.hpp>
+#include <boost/core/lightweight_test.hpp>
 #include <boost/type.hpp>
+
 using boost::implicit_cast;
 using boost::type;
 
@@ -18,8 +19,8 @@ struct foo
     operator long() const { return 0; }
 };
 
-typedef type<long> long_type;
+using long_type = type<long>;
-typedef type<foo> foo_type;
+using foo_type = type<foo>;
 
 int main()
 {
@@ -34,5 +35,9 @@ int main()
     (void)f;
     (void)z;
 
+
+    constexpr long value = boost::implicit_cast<long>(42);
+    BOOST_TEST(value == 42L);
+
     return boost::report_errors();
 }

test/polymorphic_cast_test.cpp

@@ -6,6 +6,7 @@
 // Copyright 1999 Dave Abrahams
 // Copyright 2014 Peter Dimov
 // Copyright 2014 Boris Rasin, Antony Polukhin
+// Copyright 2023 Antony Polukhin
 //
 // Distributed under the Boost Software License, Version 1.0.
 //
@@ -172,20 +173,23 @@ static void test_polymorphic_pointer_cast()
 
 static void test_polymorphic_downcast()
 {
-    Base * base = new Derived;
+    Base *base_pointer = new Derived;
 
-    Derived * derived = boost::polymorphic_downcast<Derived*>( base );
+    // test raw pointer cast
+    Derived *derived_pointer = boost::polymorphic_downcast<Derived *>(base_pointer);
 
-    BOOST_TEST( derived != 0 );
+    BOOST_TEST(derived_pointer != 0);
 
-    if( derived != 0 )
+    if (derived_pointer != 0)
     {
-        BOOST_TEST_EQ( derived->kind(), "Derived" );
+        BOOST_TEST_EQ(derived_pointer->kind(), "Derived");
     }
 
-    // polymorphic_downcast can't do crosscasts
+    // test reference cast
+    Derived& derived_ref = boost::polymorphic_downcast<Derived&>(*base_pointer);
+    BOOST_TEST_EQ(derived_ref.kind(), "Derived");
 
-    delete base;
+    delete base_pointer;
 }
 
 static void test_polymorphic_pointer_downcast_builtin()
@@ -234,8 +238,6 @@ static void test_polymorphic_pointer_downcast_intrusive()
     }
 }
 
-#ifndef BOOST_NO_CXX11_SMART_PTR
-
 static void test_polymorphic_pointer_downcast_std_shared()
 {
     std::shared_ptr<Base> base (new Derived);
@@ -250,8 +252,6 @@ static void test_polymorphic_pointer_downcast_std_shared()
     }
 }
 
-#endif
-
 static void test_polymorphic_cast_fail()
 {
     Base * base = new Base;
@@ -269,26 +269,39 @@ static void test_polymorphic_pointer_cast_fail()
 
     BOOST_TEST_THROWS( boost::polymorphic_pointer_cast<Derived>( boost::shared_ptr<Base>(new Base) ), std::bad_cast );
 
-#ifndef BOOST_NO_CXX11_SMART_PTR
     BOOST_TEST_THROWS( boost::polymorphic_pointer_cast<Derived>( std::shared_ptr<Base>(new Base) ), std::bad_cast );
-#endif
 
     BOOST_TEST_THROWS( boost::polymorphic_pointer_cast<Derived>( boost::intrusive_ptr<Base>(new Base) ), std::bad_cast );
 }
 
 static void test_polymorphic_downcast_fail()
 {
-    Base * base = new Base;
+    Base * base_pointer = new Base;
 
-    int old_count = assertion_failed_count;
+    {
-    expect_assertion = true;
+        // test raw pointer cast
 
-    BOOST_TEST_THROWS( boost::polymorphic_downcast<Derived*>( base ), expected_assertion ); // should assert
+        int old_count = assertion_failed_count;
+        expect_assertion = true;
 
-    BOOST_TEST_EQ( assertion_failed_count, old_count + 1 );
+        BOOST_TEST_THROWS(boost::polymorphic_downcast<Derived *>(base_pointer), expected_assertion); // should assert
-    expect_assertion = false;
 
-    delete base;
+        BOOST_TEST_EQ(assertion_failed_count, old_count + 1);
+        expect_assertion = false;
+    }
+    {
+        // test reference cast
+
+        int old_count = assertion_failed_count;
+        expect_assertion = true;
+
+        BOOST_TEST_THROWS(boost::polymorphic_downcast<Derived &>(*base_pointer), expected_assertion); // should assert
+
+        BOOST_TEST_EQ(assertion_failed_count, old_count + 1);
+        expect_assertion = false;
+    }
+
+    delete base_pointer;
 }
 
 static void test_polymorphic_pointer_downcast_builtin_fail()
@@ -319,7 +332,6 @@ static void test_polymorphic_pointer_downcast_boost_shared_fail()
     expect_assertion = false;
 }
 
-#ifndef BOOST_NO_CXX11_SMART_PTR
 
 static void test_polymorphic_pointer_downcast_std_shared_fail()
 {
@@ -334,7 +346,6 @@ static void test_polymorphic_pointer_downcast_std_shared_fail()
     expect_assertion = false;
 }
 
-#endif
 
 static void test_polymorphic_pointer_downcast_intrusive_fail()
 {
@@ -364,10 +375,9 @@ int main()
     test_polymorphic_pointer_downcast_boost_shared_fail();
     test_polymorphic_pointer_downcast_intrusive_fail();
 
-#ifndef BOOST_NO_CXX11_SMART_PTR
     test_polymorphic_pointer_downcast_std_shared();
     test_polymorphic_pointer_downcast_std_shared_fail();
-#endif
+
 
     return boost::report_errors();
 }