Replaced macos-11 GHA image with 12, 13 and 14 since 11 is being removed.

This fixes the deprecation warnings for actions/checkout@v3. actions/checkout@v4
is not functional because of the upstream bug:

https://github.com/actions/checkout/issues/1590

.github/workflows/ci.yml

@@ -1,4 +1,4 @@
-# Copyright 2021-2023 Andrey Semashev
+# Copyright 2021-2024 Andrey Semashev
 #
 # 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)
@@ -257,15 +257,25 @@ jobs:
             source_keys:
               - "https://apt.llvm.org/llvm-snapshot.gpg.key"
           - toolset: clang
-            compiler: clang++-16
-            cxxstd: "03-gnu,11-gnu,14-gnu,17-gnu,20-gnu,2b-gnu"
+            compiler: clang++-17
+            cxxstd: "03-gnu,11-gnu,14-gnu,17-gnu,20-gnu,23-gnu"
             os: ubuntu-22.04
             install:
-              - clang-16
-              - libc++-16-dev
-              - libc++abi-16-dev
+              - clang-17
             sources:
-              - "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-16 main"
+              - "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-17 main"
+            source_keys:
+              - "https://apt.llvm.org/llvm-snapshot.gpg.key"
+          - toolset: clang
+            compiler: clang++-17
+            cxxstd: "03-gnu,11-gnu,14-gnu,17-gnu,20-gnu,23-gnu"
+            os: ubuntu-22.04
+            install:
+              - clang-17
+              - libc++-17-dev
+              - libc++abi-17-dev
+            sources:
+              - "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-17 main"
             source_keys:
               - "https://apt.llvm.org/llvm-snapshot.gpg.key"
             cxxflags: -stdlib=libc++
@@ -285,10 +295,16 @@ jobs:
               - libc++abi-15-dev
 
           - toolset: clang
-            cxxstd: "11,14,17,2a"
-            os: macos-11
+            cxxstd: "11,14,17,20,2b"
+            os: macos-12
+          - toolset: clang
+            cxxstd: "11,14,17,20,2b"
+            os: macos-13
+          - toolset: clang
+            cxxstd: "11,14,17,20,2b"
+            os: macos-14
 
-    timeout-minutes: 60
+    timeout-minutes: 15
     runs-on: ${{matrix.os}}
     container: ${{matrix.container}}
 
@@ -317,8 +333,6 @@ jobs:
             fi
             git config --global pack.threads 0
 
-      - uses: actions/checkout@v3
-
       - name: Install packages
         if: matrix.install
         run: |
@@ -433,11 +447,25 @@ jobs:
             then
                 DEPINST_ARGS+=("--git_args" "--jobs $GIT_FETCH_JOBS")
             fi
+            mkdir -p snapshot
+            cd snapshot
+            echo "Downloading library snapshot: https://github.com/${GITHUB_REPOSITORY}/archive/${GITHUB_SHA}.tar.gz"
+            curl -L --retry "$NET_RETRY_COUNT" -o "${LIBRARY}-${GITHUB_SHA}.tar.gz" "https://github.com/${GITHUB_REPOSITORY}/archive/${GITHUB_SHA}.tar.gz"
+            tar -xf "${LIBRARY}-${GITHUB_SHA}.tar.gz"
+            if [ ! -d "${LIBRARY}-${GITHUB_SHA}" ]
+            then
+                echo "Library snapshot does not contain the library directory ${LIBRARY}-${GITHUB_SHA}:"
+                ls -la
+                exit 1
+            fi
+            rm -f "${LIBRARY}-${GITHUB_SHA}.tar.gz"
             cd ..
             git clone -b "$BOOST_BRANCH" --depth 1 "https://github.com/boostorg/boost.git" "boost-root"
             cd boost-root
-            mkdir -p libs/$LIBRARY
-            cp -r $GITHUB_WORKSPACE/* libs/$LIBRARY
+            mkdir -p libs
+            rm -rf "libs/$LIBRARY"
+            mv -f "../snapshot/${LIBRARY}-${GITHUB_SHA}" "libs/$LIBRARY"
+            rm -rf "../snapshot"
             git submodule update --init tools/boostdep
             DEPINST_ARGS+=("$LIBRARY")
             python tools/boostdep/depinst/depinst.py "${DEPINST_ARGS[@]}"
@@ -459,7 +487,7 @@ jobs:
       - name: Run tests
         if: matrix.cmake_tests == ''
         run: |
-            cd ../boost-root
+            cd boost-root
             B2_ARGS=("-j" "$BUILD_JOBS" "toolset=${{matrix.toolset}}" "cxxstd=${{matrix.cxxstd}}")
             if [ -n "${{matrix.build_variant}}" ]
             then
@@ -486,3 +514,78 @@ jobs:
             fi
             B2_ARGS+=("libs/$LIBRARY/test")
             ./b2 "${B2_ARGS[@]}"
+
+  windows:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - toolset: msvc-14.0
+            cxxstd: "14"
+            addrmd: 32,64
+            os: windows-2019
+          - toolset: msvc-14.2
+            cxxstd: "14,17,20,latest"
+            addrmd: 32,64
+            os: windows-2019
+          - toolset: msvc-14.3
+            cxxstd: "14,17,20,latest"
+            addrmd: 32,64
+            os: windows-2022
+          - toolset: clang-win
+            cxxstd: "14,17,latest"
+            addrmd: 32,64
+            os: windows-2022
+          - toolset: gcc
+            cxxstd: "11,14,17,2a"
+            addrmd: 64
+            os: windows-2019
+
+    timeout-minutes: 15
+    runs-on: ${{matrix.os}}
+
+    steps:
+      - name: Setup Boost
+        shell: cmd
+        run: |
+            echo GITHUB_REPOSITORY: %GITHUB_REPOSITORY%
+            for /f %%i in ("%GITHUB_REPOSITORY%") do set LIBRARY=%%~nxi
+            echo LIBRARY: %LIBRARY%
+            echo LIBRARY=%LIBRARY%>>%GITHUB_ENV%
+            echo GITHUB_BASE_REF: %GITHUB_BASE_REF%
+            echo GITHUB_REF: %GITHUB_REF%
+            if "%GITHUB_BASE_REF%" == "" set GITHUB_BASE_REF=%GITHUB_REF%
+            set BOOST_BRANCH=develop
+            for /f %%i in ("%GITHUB_BASE_REF%") do if "%%~nxi" == "master" set BOOST_BRANCH=master
+            echo BOOST_BRANCH: %BOOST_BRANCH%
+            mkdir snapshot
+            cd snapshot
+            echo Downloading library snapshot: https://github.com/%GITHUB_REPOSITORY%/archive/%GITHUB_SHA%.zip
+            curl -L --retry %NET_RETRY_COUNT% -o "%LIBRARY%-%GITHUB_SHA%.zip" "https://github.com/%GITHUB_REPOSITORY%/archive/%GITHUB_SHA%.zip"
+            tar -xf "%LIBRARY%-%GITHUB_SHA%.zip"
+            if not exist "%LIBRARY%-%GITHUB_SHA%\" (
+                echo Library snapshot does not contain the library directory %LIBRARY%-%GITHUB_SHA%:
+                dir
+                exit /b 1
+            )
+            del /f "%LIBRARY%-%GITHUB_SHA%.zip"
+            cd ..
+            git clone -b %BOOST_BRANCH% --depth 1 https://github.com/boostorg/boost.git boost-root
+            cd boost-root
+            if not exist "libs\" mkdir libs
+            if exist "libs\%LIBRARY%\" rmdir /s /q "libs\%LIBRARY%"
+            move /Y "..\snapshot\%LIBRARY%-%GITHUB_SHA%" "libs\%LIBRARY%"
+            rmdir /s /q "..\snapshot"
+            git submodule update --init tools/boostdep
+            python tools/boostdep/depinst/depinst.py --git_args "--jobs %GIT_FETCH_JOBS%" %LIBRARY%
+            cmd /c bootstrap
+            b2 -d0 headers
+
+      - name: Run tests
+        shell: cmd
+        run: |
+            cd boost-root
+            if not "${{matrix.cxxstd}}" == "" set CXXSTD=cxxstd=${{matrix.cxxstd}}
+            if not "${{matrix.addrmd}}" == "" set ADDRMD=address-model=${{matrix.addrmd}}
+            if not "${{matrix.build_variant}}" == "" (set BUILD_VARIANT=variant=${{matrix.build_variant}}) else (set BUILD_VARIANT=variant=%DEFAULT_BUILD_VARIANT%)
+            b2 -j %NUMBER_OF_PROCESSORS% libs/%LIBRARY%/test toolset=${{matrix.toolset}} %CXXSTD% %ADDRMD% %BUILD_VARIANT% embed-manifest-via=linker