Fixed accessing members of the dereferenced value after iterator post-increment.

The recent commit 5777e9944b broke code such as
(*it++).foo(), where the result of dereferencing would be convertible to
the value type but did not provide the members of the value type. To mitigate
this, return a reference to the value instead of a proxy object. This will only
work for non-writable iterators (and it didn't work for writable iterators
before either) because in that case a proxy is needed to be able to intercept
operator=.

Also fix a similar issue with (it++)->foo() by adding operator-> overloads
to the post-increment result proxies.

Added tests for the fixes.

.github/workflows/ci.yml

@@ -0,0 +1,472 @@
+# Copyright 2021-2022 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)
+
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+      - develop
+      - feature/**
+
+concurrency:
+  group: ${{format('{0}:{1}', github.repository, github.ref)}}
+  cancel-in-progress: true
+
+env:
+  GIT_FETCH_JOBS: 8
+  NET_RETRY_COUNT: 5
+  DEFAULT_BUILD_VARIANT: debug,release
+
+jobs:
+  posix:
+    defaults:
+      run:
+        shell: bash
+
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          # Linux, gcc
+          - toolset: gcc-4.4
+            cxxstd: "98,0x"
+            os: ubuntu-latest
+            container: ubuntu:16.04
+            install:
+              - g++-4.4
+            sources:
+              - "ppa:ubuntu-toolchain-r/test"
+          - toolset: gcc-4.6
+            cxxstd: "03,0x"
+            os: ubuntu-latest
+            container: ubuntu:16.04
+            install:
+              - g++-4.6
+            sources:
+              - "ppa:ubuntu-toolchain-r/test"
+          - toolset: gcc-4.7
+            cxxstd: "03,11"
+            os: ubuntu-latest
+            container: ubuntu:16.04
+            install:
+              - g++-4.7
+          - toolset: gcc-4.8
+            cxxstd: "03,11"
+            os: ubuntu-latest
+            container: ubuntu:18.04
+            install:
+              - g++-4.8
+          - toolset: gcc-4.9
+            cxxstd: "03,11"
+            os: ubuntu-latest
+            container: ubuntu:16.04
+            install:
+              - g++-4.9
+          - toolset: gcc-5
+            cxxstd: "03,11,14,1z"
+            os: ubuntu-latest
+            container: ubuntu:16.04
+            install:
+              - g++-5
+          - toolset: gcc-6
+            cxxstd: "03,11,14,1z"
+            os: ubuntu-latest
+            container: ubuntu:18.04
+            install:
+              - g++-6
+          - toolset: gcc-7
+            cxxstd: "03,11,14,17"
+            os: ubuntu-latest
+            container: ubuntu:18.04
+            install:
+              - g++-7
+          - toolset: gcc-8
+            cxxstd: "03,11,14,17,2a"
+            os: ubuntu-latest
+            container: ubuntu:18.04
+            install:
+              - g++-8
+          - toolset: gcc-9
+            cxxstd: "03,11,14,17,2a"
+            os: ubuntu-20.04
+            install:
+              - g++-9
+          - toolset: gcc-10
+            cxxstd: "03,11,14,17,20"
+            os: ubuntu-20.04
+            install:
+              - g++-10
+          - toolset: gcc-11
+            cxxstd: "03,11,14,17,20,23"
+            os: ubuntu-22.04
+            install:
+              - g++-11
+          - toolset: gcc-12
+            cxxstd: "03,11,14,17,20,23"
+            os: ubuntu-22.04
+            install:
+              - g++-12
+          - name: UBSAN
+            toolset: gcc-11
+            cxxstd: "03,11,14,17,20,23"
+            ubsan: 1
+            build_variant: debug
+            os: ubuntu-22.04
+            install:
+              - g++-11
+
+          # Linux, clang
+          - toolset: clang
+            compiler: clang++-3.5
+            cxxstd: "03,11"
+            os: ubuntu-latest
+            container: ubuntu:16.04
+            install:
+              - clang-3.5
+          - toolset: clang
+            compiler: clang++-3.6
+            cxxstd: "03,11,14"
+            os: ubuntu-latest
+            container: ubuntu:16.04
+            install:
+              - clang-3.6
+          - toolset: clang
+            compiler: clang++-3.7
+            cxxstd: "03,11,14"
+            os: ubuntu-latest
+            container: ubuntu:16.04
+            install:
+              - clang-3.7
+          - toolset: clang
+            compiler: clang++-3.8
+            cxxstd: "03,11,14"
+            os: ubuntu-latest
+            container: ubuntu:16.04
+            install:
+              - clang-3.8
+          - toolset: clang
+            compiler: clang++-3.9
+            cxxstd: "03,11,14"
+            os: ubuntu-latest
+            container: ubuntu:18.04
+            install:
+              - clang-3.9
+          - toolset: clang
+            compiler: clang++-4.0
+            cxxstd: "03,11,14"
+            os: ubuntu-latest
+            container: ubuntu:18.04
+            install:
+              - clang-4.0
+          - toolset: clang
+            compiler: clang++-5.0
+            cxxstd: "03,11,14,1z"
+            os: ubuntu-latest
+            container: ubuntu:18.04
+            install:
+              - clang-5.0
+          - toolset: clang
+            compiler: clang++-6.0
+            cxxstd: "03,11,14,17"
+            os: ubuntu-latest
+            container: ubuntu:18.04
+            install:
+              - clang-6.0
+          - toolset: clang
+            compiler: clang++-7
+            cxxstd: "03,11,14,17"
+            os: ubuntu-latest
+            container: ubuntu:18.04
+            install:
+              - clang-7
+          # Note: clang-8 does not fully support C++20, so it is not compatible with libstdc++-8 in this mode
+          - toolset: clang
+            compiler: clang++-8
+            cxxstd: "03,11,14,17,2a"
+            os: ubuntu-latest
+            container: ubuntu:18.04
+            install:
+              - clang-8
+              - g++-7
+            gcc_toolchain: 7
+          - toolset: clang
+            compiler: clang++-9
+            cxxstd: "03,11,14,17,2a"
+            os: ubuntu-20.04
+            install:
+              - clang-9
+          - toolset: clang
+            compiler: clang++-10
+            cxxstd: "03,11,14,17,20"
+            os: ubuntu-20.04
+            install:
+              - clang-10
+          - toolset: clang
+            compiler: clang++-11
+            cxxstd: "03,11,14,17,20"
+            os: ubuntu-22.04
+            install:
+              - clang-11
+          - toolset: clang
+            compiler: clang++-12
+            cxxstd: "03,11,14,17,20,2b"
+            os: ubuntu-22.04
+            install:
+              - clang-12
+          - toolset: clang
+            compiler: clang++-13
+            cxxstd: "03,11,14,17,20,2b"
+            os: ubuntu-22.04
+            install:
+              - clang-13
+          - toolset: clang
+            compiler: clang++-14
+            cxxstd: "03,11,14,17,20,2b"
+            os: ubuntu-22.04
+            install:
+              - clang-14
+          - toolset: clang
+            compiler: clang++-15
+            cxxstd: "03,11,14,17,20,2b"
+            os: ubuntu-22.04
+            install:
+              - clang-15
+            sources:
+              - "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-15 main"
+            source_keys:
+              - "https://apt.llvm.org/llvm-snapshot.gpg.key"
+          - toolset: clang
+            compiler: clang++-15
+            cxxstd: "03,11,14,17,20,2b"
+            os: ubuntu-22.04
+            install:
+              - clang-15
+              - libc++-15-dev
+              - libc++abi-15-dev
+            sources:
+              - "deb http://apt.llvm.org/jammy/ llvm-toolchain-jammy-15 main"
+            source_keys:
+              - "https://apt.llvm.org/llvm-snapshot.gpg.key"
+            cxxflags: -stdlib=libc++
+            linkflags: -stdlib=libc++
+          - name: UBSAN
+            toolset: clang
+            compiler: clang++-14
+            cxxstd: "03,11,14,17,20,2b"
+            cxxflags: -stdlib=libc++
+            linkflags: -stdlib=libc++
+            ubsan: 1
+            build_variant: debug
+            os: ubuntu-22.04
+            install:
+              - clang-14
+              - libc++-14-dev
+              - libc++abi-14-dev
+
+          - toolset: clang
+            cxxstd: "03,11,14,17,2a"
+            os: macos-11
+
+    timeout-minutes: 60
+    runs-on: ${{matrix.os}}
+    container: ${{matrix.container}}
+
+    steps:
+      - name: Setup environment
+        run: |
+            if [ -f "/etc/debian_version" ]
+            then
+                echo "DEBIAN_FRONTEND=noninteractive" >> $GITHUB_ENV
+                export DEBIAN_FRONTEND=noninteractive
+            fi
+            if [ -n "${{matrix.container}}" ]
+            then
+                echo "GHA_CONTAINER=${{matrix.container}}" >> $GITHUB_ENV
+                if [ -f "/etc/debian_version" ]
+                then
+                    apt-get -o Acquire::Retries=$NET_RETRY_COUNT update
+                    if [ "$(apt-cache search "^python-is-python3$" | wc -l)" -ne 0 ]
+                    then
+                        PYTHON_PACKAGE="python-is-python3"
+                    else
+                        PYTHON_PACKAGE="python"
+                    fi
+                    apt-get -o Acquire::Retries=$NET_RETRY_COUNT install -y sudo software-properties-common tzdata wget curl apt-transport-https ca-certificates make build-essential g++ $PYTHON_PACKAGE python3 perl git cmake
+                fi
+            fi
+            git config --global pack.threads 0
+
+      - uses: actions/checkout@v3
+
+      - name: Install packages
+        if: matrix.install
+        run: |
+            declare -a SOURCE_KEYS SOURCES
+            if [ -n "${{join(matrix.source_keys, ' ')}}" ]
+            then
+                SOURCE_KEYS=("${{join(matrix.source_keys, '" "')}}")
+            fi
+            if [ -n "${{join(matrix.sources, ' ')}}" ]
+            then
+                SOURCES=("${{join(matrix.sources, '" "')}}")
+            fi
+            for key in "${SOURCE_KEYS[@]}"
+            do
+                for i in {1..$NET_RETRY_COUNT}
+                do
+                    echo "Adding key: $key"
+                    wget -O - "$key" | sudo apt-key add - && break || sleep 2
+                done
+            done
+            if [ ${#SOURCES[@]} -gt 0 ]
+            then
+                APT_ADD_REPO_COMMON_ARGS=("-y")
+                APT_ADD_REPO_SUPPORTED_ARGS="$(apt-add-repository --help | perl -ne 'if (/^\s*-n/) { print "n"; } elsif (/^\s*-P/) { print "P"; } elsif (/^\s*-S/) { print "S"; } elsif (/^\s*-U/) { print "U"; }')"
+                if [ -n "$APT_ADD_REPO_SUPPORTED_ARGS" -a -z "${APT_ADD_REPO_SUPPORTED_ARGS##*n*}" ]
+                then
+                    APT_ADD_REPO_COMMON_ARGS+=("-n")
+                fi
+                APT_ADD_REPO_HAS_SOURCE_ARGS="$([ -n "$APT_ADD_REPO_SUPPORTED_ARGS" -a -z "${APT_ADD_REPO_SUPPORTED_ARGS##*P*}" -a -z "${APT_ADD_REPO_SUPPORTED_ARGS##*S*}" -a -z "${APT_ADD_REPO_SUPPORTED_ARGS##*U*}" ] && echo 1 || echo 0)"
+                for source in "${SOURCES[@]}"
+                do
+                    for i in {1..$NET_RETRY_COUNT}
+                    do
+                        APT_ADD_REPO_ARGS=("${APT_ADD_REPO_COMMON_ARGS[@]}")
+                        if [ $APT_ADD_REPO_HAS_SOURCE_ARGS -ne 0 ]
+                        then
+                            case "$source" in
+                            "ppa:"*)
+                                APT_ADD_REPO_ARGS+=("-P")
+                                ;;
+                            "deb "*)
+                                APT_ADD_REPO_ARGS+=("-S")
+                                ;;
+                            *)
+                                APT_ADD_REPO_ARGS+=("-U")
+                                ;;
+                            esac
+                        fi
+                        APT_ADD_REPO_ARGS+=("$source")
+                        echo "apt-add-repository ${APT_ADD_REPO_ARGS[@]}"
+                        sudo -E apt-add-repository "${APT_ADD_REPO_ARGS[@]}" && break || sleep 2
+                    done
+                done
+            fi
+            sudo apt-get -o Acquire::Retries=$NET_RETRY_COUNT update
+            sudo apt-get -o Acquire::Retries=$NET_RETRY_COUNT install -y ${{join(matrix.install, ' ')}}
+
+      - name: Setup GCC Toolchain
+        if: matrix.gcc_toolchain
+        run: |
+            GCC_TOOLCHAIN_ROOT="$HOME/gcc-toolchain"
+            echo "GCC_TOOLCHAIN_ROOT=\"$GCC_TOOLCHAIN_ROOT\"" >> $GITHUB_ENV
+            MULTIARCH_TRIPLET="$(dpkg-architecture -qDEB_HOST_MULTIARCH)"
+            mkdir -p "$GCC_TOOLCHAIN_ROOT"
+            ln -s /usr/include "$GCC_TOOLCHAIN_ROOT/include"
+            ln -s /usr/bin "$GCC_TOOLCHAIN_ROOT/bin"
+            mkdir -p "$GCC_TOOLCHAIN_ROOT/lib/gcc/$MULTIARCH_TRIPLET"
+            ln -s "/usr/lib/gcc/$MULTIARCH_TRIPLET/${{matrix.gcc_toolchain}}" "$GCC_TOOLCHAIN_ROOT/lib/gcc/$MULTIARCH_TRIPLET/${{matrix.gcc_toolchain}}"
+
+      - 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: $BOOST_BRANCH
+            BUILD_JOBS=$((nproc || sysctl -n hw.ncpu) 2> /dev/null)
+            echo "BUILD_JOBS=$BUILD_JOBS" >> $GITHUB_ENV
+            echo "CMAKE_BUILD_PARALLEL_LEVEL=$BUILD_JOBS" >> $GITHUB_ENV
+            DEPINST_ARGS=()
+            GIT_VERSION="$(git --version | sed -e 's/git version //')"
+            GIT_HAS_JOBS=1
+            if [ -f "/etc/debian_version" ]
+            then
+                if $(dpkg --compare-versions "$GIT_VERSION" lt 2.8.0)
+                then
+                    GIT_HAS_JOBS=0
+                fi
+            else
+                declare -a GIT_VER=(${GIT_VERSION//./ })
+                declare -a GIT_MIN_VER=(2 8 0)
+                for ((i=0; i<${#GIT_VER[@]}; i++))
+                do
+                    if [ -z "${GIT_MIN_VER[i]}" ]
+                    then
+                        GIT_MIN_VER[i]=0
+                    fi
+                    if [ "${GIT_VER[i]}" -lt "${GIT_MIN_VER[i]}" ]
+                    then
+                        GIT_HAS_JOBS=0
+                        break
+                    fi
+                done
+            fi
+            if [ "$GIT_HAS_JOBS" -ne 0 ]
+            then
+                DEPINST_ARGS+=("--git_args" "--jobs $GIT_FETCH_JOBS")
+            fi
+            cd ..
+            git clone -b "$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
+            git submodule update --init tools/boostdep
+            DEPINST_ARGS+=("$LIBRARY")
+            python tools/boostdep/depinst/depinst.py "${DEPINST_ARGS[@]}"
+            if [ -z "${{matrix.cmake_tests}}" ]
+            then
+                ./bootstrap.sh
+                ./b2 headers
+                if [ -n "${{matrix.compiler}}" -o -n "$GCC_TOOLCHAIN_ROOT" ]
+                then
+                    echo -n "using ${{matrix.toolset}} : : ${{matrix.compiler}}" > ~/user-config.jam
+                    if [ -n "$GCC_TOOLCHAIN_ROOT" ]
+                    then
+                        echo -n " : <compileflags>\"--gcc-toolchain=$GCC_TOOLCHAIN_ROOT\" <linkflags>\"--gcc-toolchain=$GCC_TOOLCHAIN_ROOT\"" >> ~/user-config.jam
+                    fi
+                    echo " ;" >> ~/user-config.jam
+                fi
+            fi
+
+      - name: Run tests
+        if: matrix.cmake_tests == ''
+        run: |
+            cd ../boost-root
+            B2_ARGS=("-j" "$BUILD_JOBS" "toolset=${{matrix.toolset}}" "cxxstd=${{matrix.cxxstd}}")
+            if [ -n "${{matrix.build_variant}}" ]
+            then
+                B2_ARGS+=("variant=${{matrix.build_variant}}")
+            else
+                B2_ARGS+=("variant=$DEFAULT_BUILD_VARIANT")
+            fi
+            if [ -n "${{matrix.threading}}" ]
+            then
+                B2_ARGS+=("threading=${{matrix.threading}}")
+            fi
+            if [ -n "${{matrix.ubsan}}" ]
+            then
+                export UBSAN_OPTIONS="print_stacktrace=1"
+                B2_ARGS+=("cxxflags=-fsanitize=undefined -fno-sanitize-recover=undefined" "linkflags=-fsanitize=undefined -fuse-ld=gold" "define=UBSAN=1" "debug-symbols=on" "visibility=global")
+            fi
+            if [ -n "${{matrix.cxxflags}}" ]
+            then
+                B2_ARGS+=("cxxflags=${{matrix.cxxflags}}")
+            fi
+            if [ -n "${{matrix.linkflags}}" ]
+            then
+                B2_ARGS+=("linkflags=${{matrix.linkflags}}")
+            fi
+            B2_ARGS+=("libs/$LIBRARY/test")
+            ./b2 "${B2_ARGS[@]}"

.travis.yml

@@ -1,415 +0,0 @@
-# Copyright 2016, 2017 Peter Dimov
-# Copyright 2019 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)
-
-language: cpp
-
-sudo: false
-
-python: "2.7"
-
-branches:
-  only:
-    - master
-    - develop
-    - /feature\/.*/
-
-env:
-  matrix:
-    - BOGUS_JOB=true
-
-matrix:
-
-  exclude:
-    - env: BOGUS_JOB=true
-
-  include:
-# gcc, Linux
-# Note: gcc-4.4 in C++0x mode fails zip_iterator tests with std::tuple
-    - os: linux
-      dist: trusty
-      compiler: gcc-4.4
-      env: TOOLSET=gcc COMPILER=g++-4.4 CXXSTD=98
-      addons:
-        apt:
-          packages:
-            - g++-4.4
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      dist: trusty
-      compiler: gcc-4.6
-      env: TOOLSET=gcc COMPILER=g++-4.6 CXXSTD=03,0x
-      addons:
-        apt:
-          packages:
-            - g++-4.6
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      dist: trusty
-      compiler: gcc-4.7
-      env: TOOLSET=gcc COMPILER=g++-4.7 CXXSTD=03,11
-      addons:
-        apt:
-          packages:
-            - g++-4.7
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      dist: xenial
-      compiler: gcc-4.8
-      env: TOOLSET=gcc COMPILER=g++-4.8 CXXSTD=03,11
-      addons:
-        apt:
-          packages:
-            - g++-4.8
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      dist: xenial
-      compiler: gcc-4.9
-      env: TOOLSET=gcc COMPILER=g++-4.9 CXXSTD=03,11
-      addons:
-        apt:
-          packages:
-            - g++-4.9
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      dist: xenial
-      compiler: gcc-5
-      env: TOOLSET=gcc COMPILER=g++-5 CXXSTD=03,11,14,1z
-      addons:
-        apt:
-          packages:
-            - g++-5
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      dist: xenial
-      compiler: gcc-6
-      env: TOOLSET=gcc COMPILER=g++-6 CXXSTD=03,11,14,1z
-      addons:
-        apt:
-          packages:
-            - g++-6
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      dist: xenial
-      compiler: gcc-7
-      env: TOOLSET=gcc COMPILER=g++-7 CXXSTD=03,11,14,17
-      addons:
-        apt:
-          packages:
-            - g++-7
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      dist: xenial
-      compiler: gcc-8
-      env: TOOLSET=gcc COMPILER=g++-8 CXXSTD=03,11,14,17,2a
-      addons:
-        apt:
-          packages:
-            - g++-8
-          sources:
-            - ubuntu-toolchain-r-test
-
-    - os: linux
-      dist: bionic
-      compiler: gcc-9
-      env: TOOLSET=gcc COMPILER=g++-9 CXXSTD=03,11,14,17,2a
-      addons:
-        apt:
-          packages:
-            - g++-9
-          sources:
-            - sourceline: "ppa:ubuntu-toolchain-r/test"
-
-    - os: linux
-      dist: bionic
-      compiler: gcc-10
-      env: TOOLSET=gcc COMPILER=g++-10 CXXSTD=03,11,14,17,20
-      addons:
-        apt:
-          packages:
-            - g++-10
-          sources:
-            - sourceline: "ppa:ubuntu-toolchain-r/test"
-
-    - os: linux
-      dist: bionic
-      compiler: gcc-UBSAN
-      env: UBSAN=1 TOOLSET=gcc COMPILER=g++-10 CXXSTD=03,11,14,17,20 UBSAN_OPTIONS=print_stacktrace=1 LINKFLAGS=-fuse-ld=gold
-      addons:
-        apt:
-          packages:
-            - g++-10
-          sources:
-            - sourceline: "ppa:ubuntu-toolchain-r/test"
-
-# clang, Linux
-    - os: linux
-      dist: trusty
-      compiler: clang-3.5
-      env: TOOLSET=clang COMPILER=clang++-3.5 CXXSTD=03,11
-      addons:
-        apt:
-          packages:
-            - clang-3.5
-            - libstdc++-4.9-dev
-          sources:
-            - ubuntu-toolchain-r-test
-            - sourceline: "deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-3.5 main"
-              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
-
-    - os: linux
-      dist: trusty
-      compiler: clang-3.6
-      env: TOOLSET=clang COMPILER=clang++-3.6 CXXSTD=03,11
-      addons:
-        apt:
-          packages:
-            - clang-3.6
-            - libstdc++-5-dev
-          sources:
-            - ubuntu-toolchain-r-test
-            - sourceline: "deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-3.6 main"
-              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
-
-    - os: linux
-      dist: trusty
-      compiler: clang-3.7
-      env: TOOLSET=clang COMPILER=clang++-3.7 CXXSTD=03,11
-      addons:
-        apt:
-          packages:
-            - clang-3.7
-            - libstdc++-5-dev
-          sources:
-            - ubuntu-toolchain-r-test
-            - sourceline: "deb http://apt.llvm.org/trusty/ llvm-toolchain-trusty-3.7 main"
-              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
-
-    - os: linux
-      dist: xenial
-      compiler: clang-3.8
-      env: TOOLSET=clang COMPILER=clang++-3.8 CXXSTD=03,11,14,1z
-      addons:
-        apt:
-          packages:
-            - clang-3.8
-            - libstdc++-6-dev
-          sources:
-            - ubuntu-toolchain-r-test
-            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-3.8 main"
-              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
-
-    - os: linux
-      dist: xenial
-      compiler: clang-3.9
-      env: TOOLSET=clang COMPILER=clang++-3.9 CXXSTD=03,11,14,1z
-      addons:
-        apt:
-          packages:
-            - clang-3.9
-            - libstdc++-6-dev
-          sources:
-            - ubuntu-toolchain-r-test
-            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-3.9 main"
-              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
-
-    - os: linux
-      dist: xenial
-      compiler: clang-4
-      env: TOOLSET=clang COMPILER=clang++-4.0 CXXSTD=03,11,14,1z
-      addons:
-        apt:
-          packages:
-            - clang-4.0
-            - libstdc++-6-dev
-          sources:
-            - ubuntu-toolchain-r-test
-            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-4.0 main"
-              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
-
-    - os: linux
-      dist: xenial
-      compiler: clang-5
-      env: TOOLSET=clang COMPILER=clang++-5.0 CXXSTD=03,11,14,1z
-      addons:
-        apt:
-          packages:
-            - clang-5.0
-            - libstdc++-7-dev
-          sources:
-            - ubuntu-toolchain-r-test
-            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-5.0 main"
-              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
-
-    - os: linux
-      dist: xenial
-      compiler: clang-6
-      env: TOOLSET=clang COMPILER=clang++-6.0 CXXSTD=03,11,14,17,2a
-      addons:
-        apt:
-          packages:
-            - clang-6.0
-            - libstdc++-8-dev
-          sources:
-            - ubuntu-toolchain-r-test
-            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-6.0 main"
-              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
-
-    - os: linux
-      dist: xenial
-      compiler: clang-7
-      env: TOOLSET=clang COMPILER=clang++-7 CXXSTD=03,11,14,17,2a
-      addons:
-        apt:
-          packages:
-            - clang-7
-            - libstdc++-8-dev
-          sources:
-            - ubuntu-toolchain-r-test
-            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-7 main"
-              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
-
-    - os: linux
-      dist: xenial
-      compiler: clang-8
-      env: TOOLSET=clang COMPILER=clang++-8 CXXSTD=03,11,14,17,2a
-      addons:
-        apt:
-          packages:
-            - clang-8
-            - libstdc++-8-dev
-          sources:
-            - ubuntu-toolchain-r-test
-            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-8 main"
-              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
-
-    - os: linux
-      dist: xenial
-      compiler: clang-9
-      env: TOOLSET=clang COMPILER=clang++-9 CXXSTD=03,11,14,17,2a
-      addons:
-        apt:
-          packages:
-            - clang-9
-            - libstdc++-9-dev
-          sources:
-            - sourceline: "ppa:ubuntu-toolchain-r/test"
-            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-9 main"
-              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
-
-    - os: linux
-      dist: xenial
-      compiler: clang-10
-      env: TOOLSET=clang COMPILER=clang++-10 CXXSTD=03,11,14,17,20
-      addons:
-        apt:
-          packages:
-            - clang-10
-            - libstdc++-9-dev
-          sources:
-            - sourceline: "ppa:ubuntu-toolchain-r/test"
-            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-10 main"
-              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
-
-    - os: linux
-      dist: xenial
-      compiler: clang-UBSAN
-      env: UBSAN=1 TOOLSET=clang COMPILER=clang++-10 CXXSTD=03,11,14,17,20 UBSAN_OPTIONS=print_stacktrace=1
-      addons:
-        apt:
-          packages:
-            - clang-10
-            - libstdc++-9-dev
-          sources:
-            - sourceline: "ppa:ubuntu-toolchain-r/test"
-            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-10 main"
-              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
-
-    - os: linux
-      dist: xenial
-      compiler: clang-libc++
-      env: TOOLSET=clang COMPILER=clang++-10 CXXSTD=03,11,14,17,20 CXXFLAGS="-stdlib=libc++" LINKFLAGS="-stdlib=libc++"
-      addons:
-        apt:
-          packages:
-            - clang-10
-            - libc++-10-dev
-            - libc++abi-10-dev
-          sources:
-            - sourceline: "ppa:ubuntu-toolchain-r/test"
-            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-10 main"
-              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
-
-    - os: linux
-      dist: xenial
-      compiler: clang-libc++-UBSAN
-      env: UBSAN=1 TOOLSET=clang COMPILER=clang++-10 CXXSTD=03,11,14,17,20 UBSAN_OPTIONS=print_stacktrace=1 CXXFLAGS="-stdlib=libc++" LINKFLAGS="-stdlib=libc++"
-      addons:
-        apt:
-          packages:
-            - clang-10
-            - libc++-10-dev
-            - libc++abi-10-dev
-          sources:
-            - sourceline: "ppa:ubuntu-toolchain-r/test"
-            - sourceline: "deb http://apt.llvm.org/xenial/ llvm-toolchain-xenial-10 main"
-              key_url: "https://apt.llvm.org/llvm-snapshot.gpg.key"
-
-# clang, OS X
-# OS X builds are slow on Travis CI
-#    - os: osx
-#      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z
-#      osx_image: xcode9.4
-#
-#    - os: osx
-#      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,1z
-#      osx_image: xcode10.3
-
-    - os: osx
-      env: TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,14,17
-      osx_image: xcode11.2
-
-install:
-  - GIT_FETCH_JOBS=8
-  - BOOST_BRANCH=develop
-  - if [ "$TRAVIS_BRANCH" = "master" ]; then BOOST_BRANCH=master; fi
-  - cd ..
-  - git clone -b $BOOST_BRANCH --depth 1 https://github.com/boostorg/boost.git boost-root
-  - cd boost-root
-  - git submodule init tools/build
-  - git submodule init tools/boostdep
-  - git submodule init tools/boost_install
-  - git submodule init libs/headers
-  - git submodule init libs/config
-  - git submodule update --jobs $GIT_FETCH_JOBS
-  - cp -r $TRAVIS_BUILD_DIR/* libs/iterator
-  - python tools/boostdep/depinst/depinst.py --git_args "--jobs $GIT_FETCH_JOBS" iterator
-  - ./bootstrap.sh
-  - ./b2 headers
-
-script:
-  - |-
-    echo "using $TOOLSET : : $COMPILER ;" > ~/user-config.jam
-  - BUILD_JOBS=`(nproc || sysctl -n hw.ncpu) 2> /dev/null`
-  - ./b2 -j $BUILD_JOBS libs/iterator/test toolset=$TOOLSET cxxstd=$CXXSTD ${UBSAN:+cxxflags=-fsanitize=undefined cxxflags=-fno-sanitize-recover=undefined linkflags=-fsanitize=undefined define=UBSAN=1 debug-symbols=on visibility=global} ${CXXFLAGS:+cxxflags="$CXXFLAGS"} ${LINKFLAGS:+linkflags="$LINKFLAGS"}
-
-notifications:
-  email:
-    on_success: always

CMakeLists.txt

@@ -3,12 +3,9 @@
 # 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
 
-# Partial (add_subdirectory only) and experimental CMake support
-# Subject to change; please do not rely on the contents of this file yet.
+cmake_minimum_required(VERSION 3.5...3.20)
 
-cmake_minimum_required(VERSION 3.5)
-
-project(BoostIterator LANGUAGES CXX)
+project(boost_iterator VERSION "${BOOST_SUPERPROJECT_VERSION}" LANGUAGES CXX)
 
 add_library(boost_iterator INTERFACE)
 add_library(Boost::iterator ALIAS boost_iterator)

README.md

@@ -0,0 +1,27 @@
+# Boost.Iterator
+
+Boost.Iterator, part of collection of the [Boost C++ Libraries](https://github.com/boostorg), provides tools for building and working with iterators in C++. The library also provides a number of iterator classes that can be used out of the box.
+
+### Directories
+
+* **doc** - Documentation sources
+* **include** - Interface headers of Boost.Iterator
+* **test** - Boost.Iterator unit tests
+* **example** - Boost.Iterator usage examples
+
+### More information
+
+* [Documentation](https://boost.org/libs/iterator)
+* [Report bugs](https://github.com/boostorg/iterator/issues/new). Be sure to mention Boost version, platform and compiler you're using. A small compilable code sample to reproduce the problem is always good as well.
+* Submit your patches as [pull requests](https://github.com/boostorg/iterator/compare) against **develop** branch. Note that by submitting patches you agree to license your modifications under the [Boost Software License, Version 1.0](https://www.boost.org/LICENSE_1_0.txt).
+
+### Build status
+
+Branch          | GitHub Actions | AppVeyor | Test Matrix | Dependencies |
+:-------------: | -------------- | -------- | ----------- | ------------ |
+[`master`](https://github.com/boostorg/iterator/tree/master) | [![GitHub Actions](https://github.com/boostorg/iterator/actions/workflows/ci.yml/badge.svg?branch=master)](https://github.com/boostorg/iterator/actions?query=branch%3Amaster) | [![AppVeyor](https://ci.appveyor.com/api/projects/status/ud8ug5aai8vd30hg/branch/master?svg=true)](https://ci.appveyor.com/project/Lastique/iterator/branch/master) | [![Tests](https://img.shields.io/badge/matrix-master-brightgreen.svg)](http://www.boost.org/development/tests/master/developer/iterator.html) | [![Dependencies](https://img.shields.io/badge/deps-master-brightgreen.svg)](https://pdimov.github.io/boostdep-report/master/iterator.html)
+[`develop`](https://github.com/boostorg/iterator/tree/develop) | [![GitHub Actions](https://github.com/boostorg/iterator/actions/workflows/ci.yml/badge.svg?branch=develop)](https://github.com/boostorg/iterator/actions?query=branch%3Adevelop) | [![AppVeyor](https://ci.appveyor.com/api/projects/status/ud8ug5aai8vd30hg/branch/develop?svg=true)](https://ci.appveyor.com/project/Lastique/iterator/branch/develop) | [![Tests](https://img.shields.io/badge/matrix-develop-brightgreen.svg)](http://www.boost.org/development/tests/develop/developer/iterator.html) | [![Dependencies](https://img.shields.io/badge/deps-develop-brightgreen.svg)](https://pdimov.github.io/boostdep-report/develop/iterator.html)
+
+### License
+
+Distributed under the [Boost Software License, Version 1.0](https://www.boost.org/LICENSE_1_0.txt).

appveyor.yml

@@ -15,22 +15,31 @@ branches:
 
 environment:
   matrix:
-    - TOOLSET: msvc-9.0,msvc-10.0,msvc-11.0,msvc-12.0
+    - TOOLSET: msvc-9.0,msvc-10.0,msvc-11.0
+      ADDRMD: 32
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
+    - TOOLSET: msvc-12.0
+      ADDRMD: 32,64
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
     - TOOLSET: msvc-14.0
+      CXXSTD: 14,latest
       ADDRMD: 32,64
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2015
     - TOOLSET: msvc-14.1
-      CXXSTD: 14,17
+      CXXSTD: 14,17,latest
       ADDRMD: 32,64
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
     - TOOLSET: msvc-14.2
       ADDRMD: 32,64
-      CXXSTD: 14,17
+      CXXSTD: 14,17,20,latest
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
+    - TOOLSET: msvc-14.3
+      ADDRMD: 32,64
+      CXXSTD: 14,17,20,latest
+      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2022
     - TOOLSET: clang-win
       ADDRMD: 32,64
-      CXXSTD: 14,17
+      CXXSTD: 14,17,latest
       APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017
     - TOOLSET: gcc
       CXXSTD: 03,11,14,1z

doc/Jamfile.v2

@@ -4,20 +4,20 @@
 
 using quickbook ;
 
-xml iterator 
-  : 
-    quickbook/iterator.qbk 
+xml iterator
+  :
+    quickbook/iterator.qbk
   ;
 
 boostbook standalone 
   : 
     iterator 
   :
-    <xsl:param>boost.root=../../../..
+    <xsl:param>"boost.root=../../../.."
     <xsl:param>toc.max.depth=3
     <xsl:param>toc.section.depth=3
     <xsl:param>chunk.section.depth=2
-    <format>pdf:<xsl:param>boost.url.prefix=http://www.boost.org/doc/libs/release/libs/iterator/doc
+    <format>pdf:<xsl:param>"boost.url.prefix=http://www.boost.org/doc/libs/release/libs/iterator/doc/html"
   ;
 
 ###############################################################################

example/node.hpp

@@ -24,7 +24,7 @@ struct node_base
 
     virtual void print(std::ostream& s) const = 0;
     virtual void double_me() = 0;
-        
+
     void append(node_base* p)
     {
         if (m_next)
@@ -32,7 +32,7 @@ struct node_base
         else
             m_next = p;
     }
-    
+
  private:
     node_base* m_next;
 };
@@ -52,9 +52,9 @@ struct node : node_base
 
     void print(std::ostream& s) const { s << this->m_value; }
     void double_me() { m_value += m_value; }
-    
+
  private:
     T m_value;
 };
-    
+
 #endif // NODE_DWA2004110_HPP

example/node_iterator1.hpp

@@ -28,10 +28,10 @@ class node_iterator
 
     void increment()
     { m_node = m_node->next(); }
-    
+
     bool equal(node_iterator const& other) const
     { return this->m_node == other.m_node; }
-    
+
     node_base& dereference() const
     { return *m_node; }
 

example/node_iterator2.hpp

@@ -38,15 +38,15 @@ class node_iter
             boost::is_convertible<OtherValue*,Value*>
           , enabler
         >::type = enabler()
-# endif 
+# endif
     )
       : m_node(other.m_node) {}
 
 
 # if !BOOST_WORKAROUND(__GNUC__, == 2)
- private: // GCC2 can't grant friendship to template member functions    
+ private: // GCC2 can't grant friendship to template member functions
     friend class boost::iterator_core_access;
-# endif 
+# endif
 
     template <class OtherValue>
     bool equal(node_iter<OtherValue> const& other) const
@@ -63,7 +63,7 @@ class node_iter
 # else
  private:
     template <class> friend class node_iter;
-# endif 
+# endif
     Value* m_node;
 };
 

example/node_iterator3.hpp

@@ -27,7 +27,7 @@ class node_iter
     typedef boost::iterator_adaptor<
         node_iter<Value>, Value*, boost::use_default, boost::forward_traversal_tag
     > super_t;
-    
+
  public:
     node_iter()
       : super_t(0) {}
@@ -43,14 +43,14 @@ class node_iter
             boost::is_convertible<OtherValue*,Value*>
           , enabler
         >::type = enabler()
-# endif 
+# endif
     )
       : super_t(other.base()) {}
 
 # if !BOOST_WORKAROUND(__GNUC__, == 2)
- private: // GCC2 can't grant friendship to template member functions    
+ private: // GCC2 can't grant friendship to template member functions
     friend class boost::iterator_core_access;
-# endif     
+# endif
     void increment() { this->base_reference() = this->base()->next(); }
 };
 

include/boost/iterator/advance.hpp

@@ -8,6 +8,7 @@
 #define BOOST_ITERATOR_ADVANCE_HPP
 
 #include <boost/config.hpp>
+#include <boost/detail/workaround.hpp>
 #include <boost/iterator/iterator_categories.hpp>
 
 namespace boost {
@@ -28,6 +29,12 @@ namespace iterators {
             }
         }
 
+#if BOOST_WORKAROUND(BOOST_GCC_VERSION, >= 40600)
+// type-limits warning issued below when n is an unsigned integral
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wtype-limits"
+#endif
+
         template <typename BidirectionalIterator, typename Distance>
         inline BOOST_CXX14_CONSTEXPR void
         advance_impl(
@@ -50,6 +57,10 @@ namespace iterators {
             }
         }
 
+#if BOOST_WORKAROUND(BOOST_GCC_VERSION, >= 40600)
+#pragma GCC diagnostic pop
+#endif
+
         template <typename RandomAccessIterator, typename Distance>
         inline BOOST_CXX14_CONSTEXPR void
         advance_impl(

include/boost/iterator/counting_iterator.hpp

@@ -5,12 +5,21 @@
 #ifndef COUNTING_ITERATOR_DWA200348_HPP
 # define COUNTING_ITERATOR_DWA200348_HPP
 
-# include <boost/iterator/iterator_adaptor.hpp>
+# include <boost/config.hpp>
+# include <boost/static_assert.hpp>
+# ifndef BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS
+# include <limits>
+# elif !BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x551))
+# include <boost/type_traits/is_convertible.hpp>
+# else
+# include <boost/type_traits/is_arithmetic.hpp>
+# endif
+# include <boost/type_traits/is_integral.hpp>
+# include <boost/type_traits/type_identity.hpp>
+# include <boost/type_traits/conditional.hpp>
+# include <boost/type_traits/integral_constant.hpp>
 # include <boost/detail/numeric_traits.hpp>
-# include <boost/mpl/bool.hpp>
-# include <boost/mpl/if.hpp>
-# include <boost/mpl/identity.hpp>
-# include <boost/mpl/eval_if.hpp>
+# include <boost/iterator/iterator_adaptor.hpp>
 
 namespace boost {
 namespace iterators {
@@ -45,7 +54,7 @@ namespace detail
            && boost::is_convertible<T,int>::value
       ));
 #  else
-    BOOST_STATIC_CONSTANT(bool, value = ::boost::is_arithmetic<T>::value);
+      BOOST_STATIC_CONSTANT(bool, value = ::boost::is_arithmetic<T>::value);
 #  endif
 
 # endif
@@ -53,23 +62,33 @@ namespace detail
 
   template <class T>
   struct is_numeric
-    : mpl::bool_<(::boost::iterators::detail::is_numeric_impl<T>::value)>
+    : boost::integral_constant<bool, ::boost::iterators::detail::is_numeric_impl<T>::value>
   {};
 
 #  if defined(BOOST_HAS_LONG_LONG)
   template <>
-  struct is_numeric< ::boost::long_long_type>
-    : mpl::true_ {};
+  struct is_numeric<boost::long_long_type>
+    : boost::true_type {};
 
   template <>
-  struct is_numeric< ::boost::ulong_long_type>
-    : mpl::true_ {};
+  struct is_numeric<boost::ulong_long_type>
+    : boost::true_type {};
+#  endif
+
+#  if defined(BOOST_HAS_INT128)
+  template <>
+  struct is_numeric<boost::int128_type>
+    : boost::true_type {};
+
+  template <>
+  struct is_numeric<boost::uint128_type>
+    : boost::true_type {};
 #  endif
 
   // Some compilers fail to have a numeric_limits specialization
   template <>
   struct is_numeric<wchar_t>
-    : mpl::true_ {};
+    : true_type {};
 
   template <class T>
   struct numeric_difference
@@ -77,27 +96,40 @@ namespace detail
       typedef typename boost::detail::numeric_traits<T>::difference_type type;
   };
 
-  BOOST_STATIC_ASSERT(is_numeric<int>::value);
+#  if defined(BOOST_HAS_INT128)
+  // std::numeric_limits, which is used by numeric_traits, is not specialized for __int128 in some standard libraries
+  template <>
+  struct numeric_difference<boost::int128_type>
+  {
+      typedef boost::int128_type type;
+  };
+
+  template <>
+  struct numeric_difference<boost::uint128_type>
+  {
+      typedef boost::int128_type type;
+  };
+#  endif
 
   template <class Incrementable, class CategoryOrTraversal, class Difference>
   struct counting_iterator_base
   {
       typedef typename detail::ia_dflt_help<
           CategoryOrTraversal
-        , mpl::eval_if<
-              is_numeric<Incrementable>
-            , mpl::identity<random_access_traversal_tag>
+        , typename boost::conditional<
+              is_numeric<Incrementable>::value
+            , boost::type_identity<random_access_traversal_tag>
             , iterator_traversal<Incrementable>
-          >
+          >::type
       >::type traversal;
 
       typedef typename detail::ia_dflt_help<
           Difference
-        , mpl::eval_if<
-              is_numeric<Incrementable>
+        , typename boost::conditional<
+              is_numeric<Incrementable>::value
             , numeric_difference<Incrementable>
             , iterator_difference<Incrementable>
-          >
+          >::type
       >::type difference;
 
       typedef iterator_adaptor<
@@ -161,9 +193,9 @@ class counting_iterator
  public:
     typedef typename super_t::difference_type difference_type;
 
-    counting_iterator() { }
+    BOOST_DEFAULTED_FUNCTION(counting_iterator(), {})
 
-    counting_iterator(counting_iterator const& rhs) : super_t(rhs.base()) {}
+    BOOST_DEFAULTED_FUNCTION(counting_iterator(counting_iterator const& rhs), : super_t(rhs.base()) {})
 
     counting_iterator(Incrementable x)
       : super_t(x)
@@ -180,6 +212,8 @@ class counting_iterator
     {}
 # endif
 
+    BOOST_DEFAULTED_FUNCTION(counting_iterator& operator=(counting_iterator const& rhs), { *static_cast< super_t* >(this) = static_cast< super_t const& >(rhs); return *this; })
+
  private:
 
     typename super_t::reference dereference() const
@@ -191,13 +225,13 @@ class counting_iterator
     difference_type
     distance_to(counting_iterator<OtherIncrementable, CategoryOrTraversal, Difference> const& y) const
     {
-      typedef typename mpl::if_<
-          detail::is_numeric<Incrementable>
-        , detail::number_distance<difference_type, Incrementable, OtherIncrementable>
-        , detail::iterator_distance<difference_type, Incrementable, OtherIncrementable>
-      >::type d;
+        typedef typename boost::conditional<
+            detail::is_numeric<Incrementable>::value
+          , detail::number_distance<difference_type, Incrementable, OtherIncrementable>
+          , detail::iterator_distance<difference_type, Incrementable, OtherIncrementable>
+        >::type d;
 
-      return d::distance(this->base(), y.base());
+        return d::distance(this->base(), y.base());
     }
 };
 
@@ -206,8 +240,8 @@ template <class Incrementable>
 inline counting_iterator<Incrementable>
 make_counting_iterator(Incrementable x)
 {
-  typedef counting_iterator<Incrementable> result_t;
-  return result_t(x);
+    typedef counting_iterator<Incrementable> result_t;
+    return result_t(x);
 }
 
 } // namespace iterators

include/boost/iterator/detail/config_def.hpp

@@ -18,9 +18,9 @@
 
 #ifdef BOOST_ITERATOR_CONFIG_DEF
 # error you have nested config_def #inclusion.
-#else 
+#else
 # define BOOST_ITERATOR_CONFIG_DEF
-#endif 
+#endif
 
 // We enable this always now.  Otherwise, the simple case in
 // libs/iterator/test/constant_iterator_arrow.cpp fails to compile
@@ -50,7 +50,7 @@
     || (BOOST_WORKAROUND(BOOST_INTEL_CXX_VERSION, <= 700) && defined(_MSC_VER)) \
     || BOOST_WORKAROUND(__DECCXX_VER, BOOST_TESTED_AT(60590042))                \
     || BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x590))
-    
+
 # define BOOST_NO_LVALUE_RETURN_DETECTION
 
 # if 0 // test code
@@ -79,7 +79,7 @@
 
   int z2[(lvalue_deref_helper<v*>::value == 1) ? 1 : -1];
   int z[(lvalue_deref_helper<value_iterator>::value) == 1 ? -1 : 1 ];
-# endif 
+# endif
 
 #endif
 
@@ -112,7 +112,7 @@
 
 #if !defined(BOOST_MSVC) && (defined(BOOST_NO_SFINAE) || defined(BOOST_NO_IS_CONVERTIBLE) || defined(BOOST_NO_IS_CONVERTIBLE_TEMPLATE))
 # define BOOST_NO_STRICT_ITERATOR_INTEROPERABILITY
-#endif 
+#endif
 
 # if BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x564))
 
@@ -123,6 +123,6 @@
 // instantiation stack backtrace.  They may be due in part to the fact
 // that it drops cv-qualification willy-nilly in templates.
 #  define BOOST_NO_ONE_WAY_ITERATOR_INTEROP
-# endif 
+# endif
 
 // no include guard; multiple inclusion intended

include/boost/iterator/detail/config_undef.hpp

@@ -21,4 +21,4 @@
 # undef BOOST_ITERATOR_CONFIG_DEF
 #else
 # error missing or nested #include config_def
-#endif 
+#endif

include/boost/iterator/detail/enable_if.hpp

@@ -7,10 +7,11 @@
 #ifndef BOOST_ENABLE_IF_23022003THW_HPP
 #define BOOST_ENABLE_IF_23022003THW_HPP
 
-#include <boost/detail/workaround.hpp>
-#include <boost/mpl/identity.hpp>
-
+#include <boost/config.hpp>
 #include <boost/iterator/detail/config_def.hpp>
+#if defined(BOOST_NO_SFINAE) || defined(BOOST_NO_IS_CONVERTIBLE)
+#include <boost/type_traits/type_identity.hpp>
+#endif
 
 //
 // Boost iterators uses its own enable_if cause we need
@@ -48,7 +49,6 @@ namespace boost
       struct base
       {
 #ifdef BOOST_NO_SFINAE
-
         typedef T type;
 
         // This way to do it would give a nice error message containing
@@ -69,7 +69,7 @@ namespace boost
 # if !defined(BOOST_NO_SFINAE) && !defined(BOOST_NO_IS_CONVERTIBLE)
       : enabled<(Cond::value)>::template base<Return>
 # else
-      : mpl::identity<Return>
+      : boost::type_identity<Return>
 # endif
     {
     };

include/boost/iterator/function_input_iterator.hpp

@@ -12,7 +12,7 @@
 #include <boost/config.hpp>
 #include <boost/assert.hpp>
 #include <boost/core/addressof.hpp>
-#include <boost/mpl/if.hpp>
+#include <boost/type_traits/conditional.hpp>
 #include <boost/function_types/is_function_pointer.hpp>
 #include <boost/function_types/result_type.hpp>
 #include <boost/iterator/iterator_facade.hpp>
@@ -28,6 +28,9 @@ namespace boost {
 
 namespace iterators {
 
+    template <class Function, class Input>
+    class function_input_iterator;
+
     namespace impl {
 
         // Computes the return type of an lvalue-call with an empty argument,
@@ -38,7 +41,7 @@ namespace iterators {
         {
             typedef typename result_of<
 #ifdef BOOST_RESULT_OF_USE_TR1
-                typename mpl::if_<is_function<F>, F&, F>::type()
+                typename boost::conditional<is_function<F>::value, F&, F>::type()
 #else
                 F&()
 #endif
@@ -46,21 +49,21 @@ namespace iterators {
         };
 
         template <class Function, class Input>
-        class function_input_iterator
-            : public iterator_facade<
-            function_input_iterator<Function, Input>,
-            typename result_of_nullary_lvalue_call<Function>::type,
-            single_pass_traversal_tag,
-            typename result_of_nullary_lvalue_call<Function>::type const &
+        class function_object_input_iterator :
+            public iterator_facade<
+                iterators::function_input_iterator<Function, Input>,
+                typename result_of_nullary_lvalue_call<Function>::type,
+                single_pass_traversal_tag,
+                typename result_of_nullary_lvalue_call<Function>::type const &
             >
         {
         public:
-            function_input_iterator() {}
-            function_input_iterator(Function & f_, Input state_ = Input())
+            function_object_input_iterator() {}
+            function_object_input_iterator(Function & f_, Input state_ = Input())
                 : f(boost::addressof(f_)), state(state_) {}
 
             void increment() {
-                if(value)
+                if (value)
                     value = none;
                 else
                     (*f)();
@@ -69,10 +72,12 @@ namespace iterators {
 
             typename result_of_nullary_lvalue_call<Function>::type const &
                 dereference() const {
-                    return (value ? value : value = (*f)()).get();
+                if (!value)
+                    value = (*f)();
+                return value.get();
             }
 
-            bool equal(function_input_iterator const & other) const {
+            bool equal(function_object_input_iterator const & other) const {
                 return f == other.f && state == other.state;
             }
 
@@ -83,12 +88,12 @@ namespace iterators {
         };
 
         template <class Function, class Input>
-        class function_pointer_input_iterator
-            : public iterator_facade<
-            function_pointer_input_iterator<Function, Input>,
-            typename function_types::result_type<Function>::type,
-            single_pass_traversal_tag,
-            typename function_types::result_type<Function>::type const &
+        class function_pointer_input_iterator :
+            public iterator_facade<
+                iterators::function_input_iterator<Function, Input>,
+                typename function_types::result_type<Function>::type,
+                single_pass_traversal_tag,
+                typename function_types::result_type<Function>::type const &
             >
         {
         public:
@@ -97,7 +102,7 @@ namespace iterators {
                 : f(f_), state(state_) {}
 
             void increment() {
-                if(value)
+                if (value)
                     value = none;
                 else
                     (*f)();
@@ -106,7 +111,9 @@ namespace iterators {
 
             typename function_types::result_type<Function>::type const &
                 dereference() const {
-                    return (value ? value : value = (*f)()).get();
+                if (!value)
+                    value = (*f)();
+                return value.get();
             }
 
             bool equal(function_pointer_input_iterator const & other) const {
@@ -122,17 +129,17 @@ namespace iterators {
     } // namespace impl
 
     template <class Function, class Input>
-    class function_input_iterator
-        : public mpl::if_<
-            function_types::is_function_pointer<Function>,
+    class function_input_iterator :
+        public boost::conditional<
+            function_types::is_function_pointer<Function>::value,
             impl::function_pointer_input_iterator<Function,Input>,
-            impl::function_input_iterator<Function,Input>
+            impl::function_object_input_iterator<Function,Input>
         >::type
     {
-        typedef typename mpl::if_<
-            function_types::is_function_pointer<Function>,
+        typedef typename boost::conditional<
+            function_types::is_function_pointer<Function>::value,
             impl::function_pointer_input_iterator<Function,Input>,
-            impl::function_input_iterator<Function,Input>
+            impl::function_object_input_iterator<Function,Input>
         >::type base_type;
     public:
         function_input_iterator(Function & f, Input i)
@@ -153,7 +160,8 @@ namespace iterators {
             return result_t(f, state);
     }
 
-    struct infinite {
+    struct infinite
+    {
         infinite & operator++() { return *this; }
         infinite & operator++(int) { return *this; }
         bool operator==(infinite &) const { return false; };

include/boost/iterator/function_output_iterator.hpp

@@ -12,13 +12,53 @@
 #define BOOST_ITERATOR_FUNCTION_OUTPUT_ITERATOR_HPP
 
 #include <iterator>
+#include <boost/config.hpp>
+#include <boost/core/enable_if.hpp>
+#include <boost/type_traits/is_same.hpp>
+#include <boost/type_traits/remove_cv.hpp>
+#ifndef BOOST_NO_CXX11_RVALUE_REFERENCES
+#include <boost/type_traits/remove_reference.hpp>
+#endif
 
 namespace boost {
 namespace iterators {
 
   template <class UnaryFunction>
   class function_output_iterator {
+  private:
     typedef function_output_iterator self;
+
+    class output_proxy {
+    public:
+      explicit output_proxy(UnaryFunction& f) BOOST_NOEXCEPT : m_f(f) { }
+
+#ifdef BOOST_NO_CXX11_RVALUE_REFERENCES
+      template <class T>
+      typename boost::disable_if_c<
+        boost::is_same< typename boost::remove_cv< T >::type, output_proxy >::value,
+        output_proxy&
+      >::type operator=(const T& value) {
+        m_f(value);
+        return *this;
+      }
+#else
+      template <class T>
+      typename boost::disable_if_c<
+        boost::is_same< typename boost::remove_cv< typename boost::remove_reference< T >::type >::type, output_proxy >::value,
+        output_proxy&
+      >::type operator=(T&& value) {
+        m_f(static_cast< T&& >(value));
+        return *this;
+      }
+#endif
+
+      BOOST_DEFAULTED_FUNCTION(output_proxy(output_proxy const& that), BOOST_NOEXCEPT : m_f(that.m_f) {})
+      BOOST_DELETED_FUNCTION(output_proxy& operator=(output_proxy const&))
+
+    private:
+      UnaryFunction& m_f;
+    };
+
   public:
     typedef std::output_iterator_tag iterator_category;
     typedef void                value_type;
@@ -31,17 +71,10 @@ namespace iterators {
     explicit function_output_iterator(const UnaryFunction& f)
       : m_f(f) {}
 
-    struct output_proxy {
-      output_proxy(UnaryFunction& f) : m_f(f) { }
-      template <class T> output_proxy& operator=(const T& value) {
-        m_f(value);
-        return *this;
-      }
-      UnaryFunction& m_f;
-    };
     output_proxy operator*() { return output_proxy(m_f); }
     self& operator++() { return *this; }
     self& operator++(int) { return *this; }
+
   private:
     UnaryFunction m_f;
   };

include/boost/iterator/iterator_facade.hpp

@@ -154,79 +154,160 @@ namespace iterators {
     class postfix_increment_proxy
     {
         typedef typename iterator_value<Iterator>::type value_type;
+
      public:
         explicit postfix_increment_proxy(Iterator const& x)
-          : stored_value(*x)
+          : stored_iterator(x)
+          , stored_value(*x)
         {}
 
         // Returning a mutable reference allows nonsense like
         // (*r++).mutate(), but it imposes fewer assumptions about the
         // behavior of the value_type.  In particular, recall that
         // (*r).mutate() is legal if operator* returns by value.
-        value_type&
-        operator*() const
-        {
-            return this->stored_value;
-        }
-     private:
-        mutable value_type stored_value;
-    };
-
-    //
-    // In general, we can't determine that such an iterator isn't
-    // writable -- we also need to store a copy of the old iterator so
-    // that it can be written into.
-    template <class Iterator>
-    class writable_postfix_increment_proxy
-    {
-        typedef typename iterator_value<Iterator>::type value_type;
-     public:
-        explicit writable_postfix_increment_proxy(Iterator const& x)
-          : stored_value(*x)
-          , stored_iterator(x)
-        {}
-
-        // Dereferencing must return a proxy so that both *r++ = o and
-        // value_type(*r++) can work.  In this case, *r is the same as
-        // *r++, and the conversion operator below is used to ensure
-        // readability.
-        writable_postfix_increment_proxy const&
-        operator*() const
-        {
-            return *this;
-        }
-
         // Provides readability of *r++
-        operator value_type&() const
+        value_type& operator*() const
         {
             return stored_value;
         }
 
-        // Provides writability of *r++
-        template <class T>
-        T const& operator=(T const& x) const
-        {
-            *this->stored_iterator = x;
-            return x;
-        }
-
-        // This overload just in case only non-const objects are writable
-        template <class T>
-        T& operator=(T& x) const
-        {
-            *this->stored_iterator = x;
-            return x;
-        }
-
         // Provides X(r++)
         operator Iterator const&() const
         {
             return stored_iterator;
         }
 
+        // Provides (r++)->foo()
+        value_type* operator->() const
+        {
+            return boost::addressof(stored_value);
+        }
+
      private:
-        mutable value_type stored_value;
         Iterator stored_iterator;
+        mutable value_type stored_value;
+    };
+
+
+    template <class Iterator>
+    class writable_postfix_increment_dereference_proxy;
+
+    template <class T>
+    struct is_not_writable_postfix_increment_dereference_proxy :
+        public boost::true_type
+    {};
+
+    template <class Iterator>
+    struct is_not_writable_postfix_increment_dereference_proxy<
+        writable_postfix_increment_dereference_proxy<Iterator>
+    > :
+        public boost::false_type
+    {};
+
+    template <class Iterator>
+    class writable_postfix_increment_proxy;
+
+    //
+    // In general, we can't determine that such an iterator isn't
+    // writable -- we also need to store a copy of the old iterator so
+    // that it can be written into.
+    template <class Iterator>
+    class writable_postfix_increment_dereference_proxy
+    {
+        friend class writable_postfix_increment_proxy<Iterator>;
+
+        typedef typename iterator_value<Iterator>::type value_type;
+
+     public:
+        explicit writable_postfix_increment_dereference_proxy(Iterator const& x)
+          : stored_iterator(x)
+          , stored_value(*x)
+        {}
+
+        // Provides readability of *r++
+        operator value_type&() const
+        {
+            return this->stored_value;
+        }
+
+        template <class OtherIterator>
+        writable_postfix_increment_dereference_proxy const&
+        operator=(writable_postfix_increment_dereference_proxy<OtherIterator> const& x) const
+        {
+            typedef typename iterator_value<OtherIterator>::type other_value_type;
+            *this->stored_iterator = static_cast<other_value_type&>(x);
+            return *this;
+        }
+
+        // Provides writability of *r++
+#if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
+        template <class T>
+        typename iterators::enable_if<
+            is_not_writable_postfix_increment_dereference_proxy< T >,
+            writable_postfix_increment_dereference_proxy const&
+        >::type operator=(T&& x) const
+        {
+            *this->stored_iterator = static_cast< T&& >(x);
+            return *this;
+        }
+#else
+        template <class T>
+        typename iterators::enable_if<
+            is_not_writable_postfix_increment_dereference_proxy< T >,
+            writable_postfix_increment_dereference_proxy const&
+        >::type operator=(T const& x) const
+        {
+            *this->stored_iterator = x;
+            return *this;
+        }
+
+        // This overload just in case only non-const objects are writable
+        template <class T>
+        typename iterators::enable_if<
+            is_not_writable_postfix_increment_dereference_proxy< T >,
+            writable_postfix_increment_dereference_proxy const&
+        >::type operator=(T& x) const
+        {
+            *this->stored_iterator = x;
+            return *this;
+        }
+#endif
+
+     private:
+        Iterator stored_iterator;
+        mutable value_type stored_value;
+    };
+
+    template <class Iterator>
+    class writable_postfix_increment_proxy
+    {
+        typedef typename iterator_value<Iterator>::type value_type;
+
+     public:
+        explicit writable_postfix_increment_proxy(Iterator const& x)
+          : dereference_proxy(x)
+        {}
+
+        writable_postfix_increment_dereference_proxy<Iterator> const&
+        operator*() const
+        {
+            return dereference_proxy;
+        }
+
+        // Provides X(r++)
+        operator Iterator const&() const
+        {
+            return dereference_proxy.stored_iterator;
+        }
+
+        // Provides (r++)->foo()
+        value_type* operator->() const
+        {
+            return boost::addressof(dereference_proxy.stored_value);
+        }
+
+     private:
+        writable_postfix_increment_dereference_proxy<Iterator> dereference_proxy;
     };
 
 # ifdef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

include/boost/iterator/new_iterator_tests.hpp

@@ -87,11 +87,11 @@ void readable_iterator_test(const Iterator i1, T v)
 
 # if !BOOST_WORKAROUND(__MWERKS__, <= 0x2407)
   readable_iterator_traversal_test(i1, v, detail::is_postfix_incrementable<Iterator>());
-      
+
   // I think we don't really need this as it checks the same things as
   // the above code.
   BOOST_STATIC_ASSERT(is_readable_iterator<Iterator>::value);
-# endif 
+# endif
 }
 
 template <class Iterator, class T>
@@ -106,7 +106,7 @@ void writable_iterator_test(Iterator i, T v, T v2)
           detail::is_incrementable<Iterator>
         , detail::is_postfix_incrementable<Iterator>
       >());
-# endif 
+# endif
 }
 
 template <class Iterator>
@@ -131,7 +131,7 @@ void constant_lvalue_iterator_test(Iterator i, T v1)
 # ifndef BOOST_NO_LVALUE_RETURN_DETECTION
   BOOST_STATIC_ASSERT(is_lvalue_iterator<Iterator>::value);
   BOOST_STATIC_ASSERT(!is_non_const_lvalue_iterator<Iterator>::value);
-# endif 
+# endif
 }
 
 template <class Iterator, class T>
@@ -143,17 +143,17 @@ void non_const_lvalue_iterator_test(Iterator i, T v1, T v2)
   BOOST_STATIC_ASSERT((is_same<value_type&, reference>::value));
   T& v3 = *i2;
   BOOST_TEST(v1 == v3);
-  
+
   // A non-const lvalue iterator is not neccessarily writable, but we
   // are assuming the value_type is assignable here
   *i = v2;
-  
+
   T& v4 = *i2;
   BOOST_TEST(v2 == v4);
 # ifndef BOOST_NO_LVALUE_RETURN_DETECTION
   BOOST_STATIC_ASSERT(is_lvalue_iterator<Iterator>::value);
   BOOST_STATIC_ASSERT(is_non_const_lvalue_iterator<Iterator>::value);
-# endif 
+# endif
 }
 
 template <class Iterator, class T>
@@ -248,7 +248,7 @@ void random_access_readable_iterator_test(Iterator i, int N, TrueVals vals)
     BOOST_TEST(*i == vals[N - 1 - c]);
     typename std::iterator_traits<Iterator>::value_type x = j[N - 1 - c];
     BOOST_TEST(*i == x);
-    Iterator q = k - c; 
+    Iterator q = k - c;
     BOOST_TEST(*i == *q);
     BOOST_TEST(i > j);
     BOOST_TEST(i >= j);

include/boost/iterator/transform_iterator.hpp

@@ -7,11 +7,11 @@
 #ifndef BOOST_TRANSFORM_ITERATOR_23022003THW_HPP
 #define BOOST_TRANSFORM_ITERATOR_23022003THW_HPP
 
+#include <boost/config.hpp>
+#include <boost/config/workaround.hpp>
 #include <boost/iterator/detail/enable_if.hpp>
 #include <boost/iterator/iterator_adaptor.hpp>
 #include <boost/iterator/iterator_categories.hpp>
-#include <boost/mpl/not.hpp>
-#include <boost/mpl/bool.hpp>
 #include <boost/type_traits/function_traits.hpp>
 #include <boost/type_traits/is_const.hpp>
 #include <boost/type_traits/is_class.hpp>
@@ -24,7 +24,11 @@
 #include <iterator>
 
 #if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1310))
-# include <boost/type_traits/is_base_and_derived.hpp>
+#include <boost/type_traits/is_base_and_derived.hpp>
+#endif
+
+#if !BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))
+#include <boost/static_assert.hpp>
 #endif
 
 #include <boost/iterator/detail/config_def.hpp>
@@ -154,7 +158,7 @@ namespace iterators {
       return transform_iterator<UnaryFunc, Iterator>(it, UnaryFunc());
   }
 
-#if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION ) && !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)
+#if defined(BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION) && !defined(BOOST_NO_FUNCTION_TEMPLATE_ORDERING)
   template <class Return, class Argument, class Iterator>
   inline transform_iterator< Return (*)(Argument), Iterator, Return>
   make_transform_iterator(Iterator it, Return (*fun)(Argument))

meta/libraries.json

@@ -14,5 +14,6 @@
         "David Abrahams <dave -at- boost-consulting.com>",
         "Thomas Witt <witt - at - acm.org>",
         "Jeffrey Lee Hellrung Jr. <jeffrey.hellrung -at- gmail.com>"
-    ]
+    ],
+    "cxxstd": "03"
 }

test/Jamfile.v2

@@ -50,6 +50,8 @@ test-suite iterator
     [ run permutation_iterator_test.cpp : : : # <stlport-iostream>on
     ]
     [ run function_input_iterator_test.cpp ]
+    [ run function_output_iterator_test.cpp ]
+    [ compile-fail function_output_iterator_cf.cpp ]
 
     [ run generator_iterator_test.cpp ]
 

test/counting_iterator_test.cpp

@@ -30,7 +30,7 @@
 #include <boost/iterator/new_iterator_tests.hpp>
 
 #include <boost/next_prior.hpp>
-#include <boost/mpl/if.hpp>
+#include <boost/type_traits/conditional.hpp>
 #include <boost/detail/workaround.hpp>
 #include <boost/limits.hpp>
 
@@ -68,7 +68,7 @@ struct unsigned_assert_nonnegative
 
 template <class T>
 struct assert_nonnegative
-  : boost::mpl::if_c<
+  : boost::conditional<
         std::numeric_limits<T>::is_signed
       , signed_assert_nonnegative<T>
       , unsigned_assert_nonnegative<T>
@@ -271,8 +271,12 @@ int main()
     test_integer<long>();
     test_integer<unsigned long>();
 #if defined(BOOST_HAS_LONG_LONG)
-    test_integer< ::boost::long_long_type>();
-    test_integer< ::boost::ulong_long_type>();
+    test_integer<boost::long_long_type>();
+    test_integer<boost::ulong_long_type>();
+#endif
+#if defined(BOOST_HAS_INT128)
+    test_integer<boost::int128_type>();
+    test_integer<boost::uint128_type>();
 #endif
 
     // Test user-defined type.

test/function_input_iterator_test.cpp

@@ -99,6 +99,15 @@ int main()
     for(std::size_t i = 0; i != 10; ++i)
         BOOST_TEST_EQ(generated[i], static_cast<int>(42 + i));
 
+    // Test that incrementing the iterator returns a reference to the iterator type
+    {
+        typedef boost::iterators::function_input_iterator<counter, int> function_counter_iterator_t;
+        function_counter_iterator_t it1(counter_generator, 0);
+        function_counter_iterator_t it2(++it1);
+        function_counter_iterator_t it3(it2++);
+        BOOST_TEST_EQ(*it3, 54);
+    }
+
 #if !defined(BOOST_NO_CXX11_LAMBDAS) && !defined(BOOST_NO_CXX11_AUTO_DECLARATIONS) \
     && defined(BOOST_RESULT_OF_USE_DECLTYPE)
     // test the iterator with lambda expressions

test/function_output_iterator_cf.cpp

@@ -0,0 +1,37 @@
+// Copyright 2022 (c) Andrey Semashev
+// 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 <boost/iterator/function_output_iterator.hpp>
+
+namespace {
+
+struct sum_func
+{
+    typedef void result_type;
+
+    explicit sum_func(int& n) : m_n(n) {}
+    result_type operator() (int x) const
+    {
+        m_n += x;
+    }
+
+private:
+    int& m_n;
+};
+
+} // namespace
+
+int main()
+{
+    int n = 0;
+    boost::iterators::function_output_iterator< sum_func > it1 =
+        boost::iterators::make_function_output_iterator(sum_func(n));
+    boost::iterators::function_output_iterator< sum_func > it2 =
+        boost::iterators::make_function_output_iterator(sum_func(n));
+
+    *it1 = *it2;
+
+    return 0;
+}

test/function_output_iterator_test.cpp

@@ -0,0 +1,61 @@
+// Copyright 2022 (c) Andrey Semashev
+// 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 <boost/config.hpp>
+
+#include <boost/core/lightweight_test.hpp>
+#include <boost/iterator/function_output_iterator.hpp>
+
+namespace {
+
+struct sum_func
+{
+    typedef void result_type;
+
+    explicit sum_func(int& n) : m_n(n) {}
+    result_type operator() (int x) const
+    {
+        m_n += x;
+    }
+
+private:
+    int& m_n;
+};
+
+} // namespace
+
+int main()
+{
+    {
+        int n = 0;
+        boost::iterators::function_output_iterator< sum_func > it =
+            boost::iterators::make_function_output_iterator(sum_func(n));
+
+        *it = 1;
+        ++it;
+        *it = 2;
+        ++it;
+        *it = 3;
+
+        BOOST_TEST_EQ(n, 6);
+    }
+
+#if !defined(BOOST_NO_CXX11_LAMBDAS) && !defined(BOOST_NO_CXX11_AUTO_DECLARATIONS)
+    {
+        int n = 0;
+        auto it = boost::iterators::make_function_output_iterator([&n](int x) { n -= x; });
+
+        *it = 1;
+        ++it;
+        *it = 2;
+        ++it;
+        *it = 3;
+
+        BOOST_TEST_EQ(n, -6);
+    }
+#endif
+
+    return boost::report_errors();
+}

test/iterator_facade.cpp

@@ -10,7 +10,7 @@
 #include <boost/call_traits.hpp>
 #include <boost/polymorphic_cast.hpp>
 #include <boost/type_traits/is_convertible.hpp>
-#include <boost/utility/enable_if.hpp>
+#include <boost/core/enable_if.hpp>
 
 // This is a really, really limited test so far.  All we're doing
 // right now is checking that the postfix++ proxy for single-pass
@@ -63,7 +63,23 @@ struct proxy
 
 struct value
 {
-    void mutator() {} // non-const member function
+    int increment_count;
+    int private_mutator_count;
+    int& shared_mutator_count;
+
+    explicit value(int& shared_mutator_count) :
+        increment_count(0),
+        private_mutator_count(0),
+        shared_mutator_count(shared_mutator_count)
+    {
+    }
+
+    // non-const member function
+    void mutator()
+    {
+        ++private_mutator_count;
+        ++shared_mutator_count;
+    }
 };
 
 struct input_iter
@@ -75,21 +91,25 @@ struct input_iter
     >
 {
  public:
-    input_iter() {}
+    explicit input_iter(value& val) : state(&val) {}
 
     void increment()
     {
+        ++(state->increment_count);
     }
     value
     dereference() const
     {
-        return value();
+        return *state;
     }
 
     bool equal(input_iter const&) const
     {
         return false;
     }
+
+ private:
+    value* state;
 };
 
 template <class T>
@@ -198,13 +218,30 @@ int main()
     {
         // test for a fix to http://tinyurl.com/zuohe
         // These two lines should be equivalent (and both compile)
-        input_iter p;
+        int shared_mutator_count = 0;
+        value val(shared_mutator_count);
+        input_iter p(val);
         (*p).mutator();
         p->mutator();
+        BOOST_TEST_EQ(val.increment_count, 0);
+        BOOST_TEST_EQ(val.private_mutator_count, 0); // mutator() should be invoked on an object returned by value
+        BOOST_TEST_EQ(shared_mutator_count, 2);
 
         same_type<input_iter::pointer>(p.operator->());
     }
 
+    {
+        // Test that accessing dereferenced value of a post-incremented iterator works
+        int shared_mutator_count = 0;
+        value val(shared_mutator_count);
+        input_iter p(val);
+        (*p++).mutator();
+        (p++)->mutator();
+        BOOST_TEST_EQ(val.increment_count, 2);
+        BOOST_TEST_EQ(val.private_mutator_count, 0); // mutator() should be invoked on an object returned by value
+        BOOST_TEST_EQ(shared_mutator_count, 2);
+    }
+
     {
         int x = 0;
         iterator_with_proxy_reference i(x);

test/iterator_traits_test.cpp

@@ -155,10 +155,11 @@ input_iterator_test<std::istream_iterator<int>, int, std::ptrdiff_t, int*, int&,
 
 // C++20 changed ostream_iterator::difference_type to ptrdiff_t.
 // Note: gcc 10.1 defines __cplusplus to a value less than 202002L, but greater than 201703L in C++20 mode.
-#if __cplusplus > 201703L && (\
-    (defined(BOOST_LIBSTDCXX_VERSION) && BOOST_LIBSTDCXX_VERSION >= 100100) \
-    ) || \
-    defined(_MSVC_LANG) && _MSVC_LANG > 201703L && _MSVC_STL_UPDATE >= 202010L
+#if (__cplusplus > 201703L && ( \
+        (defined(BOOST_LIBSTDCXX_VERSION) && BOOST_LIBSTDCXX_VERSION >= 100100) || \
+        (defined(_LIBCPP_VERSION) && _LIBCPP_VERSION >= 12000) \
+    )) || \
+    (defined(_MSVC_LANG) && _MSVC_LANG > 201703L && _MSVC_STL_UPDATE >= 202010L)
 #define BOOST_ITERATOR_CXX20_OSTREAM_ITERATOR
 #endif
 

test/permutation_iterator_test.cpp

@@ -5,7 +5,7 @@
 // http://www.boost.org/LICENSE_1_0.txt)
 
 #include <boost/config.hpp>
-#include <boost/test/minimal.hpp>
+#include <boost/core/lightweight_test.hpp>
 
 #include <boost/iterator/permutation_iterator.hpp>
 #include <boost/static_assert.hpp>
@@ -59,14 +59,14 @@ void permutation_test()
   permutation_type it = begin;
   permutation_type end = boost::make_permutation_iterator( elements.begin(), indices.end() );
 
-  BOOST_CHECK( it == begin );
-  BOOST_CHECK( it != end );
+  BOOST_TEST( it == begin );
+  BOOST_TEST( it != end );
 
-  BOOST_CHECK( std::distance( begin, end ) == index_size );
+  BOOST_TEST( std::distance( begin, end ) == index_size );
 
   for( index_type::iterator i_it1 = indices.begin(); it != end; ++i_it1, ++it )
   {
-    BOOST_CHECK( *it == elements[ *i_it1 ] );
+    BOOST_TEST( *it == elements[ *i_it1 ] );
   }
 
   it = begin;
@@ -74,14 +74,14 @@ void permutation_test()
   {
     index_type::iterator i_it2 = indices.begin();
     std::advance( i_it2, i1 );
-    BOOST_CHECK( *it == elements[ *i_it2 ] );
+    BOOST_TEST( *it == elements[ *i_it2 ] );
   }
 
   it = begin;
   std::advance(it, index_size);
   for( index_type::iterator i_it3 = indices.end(); it != begin; )
   {
-    BOOST_CHECK( *--it == elements[ *--i_it3 ] );
+    BOOST_TEST( *--it == elements[ *--i_it3 ] );
   }
 
   it = begin;
@@ -90,14 +90,14 @@ void permutation_test()
   {
     index_type::iterator i_it4 = --indices.end();
     std::advance( i_it4, -i2 );
-    BOOST_CHECK( *--it == elements[ *i_it4 ] );
+    BOOST_TEST( *--it == elements[ *i_it4 ] );
   }
 
 }
 
 
-int test_main(int, char *[])
+int main()
 {
   permutation_test();
-  return 0;
+  return boost::report_errors();
 }

test/zip_iterator_test2_std_tuple.cpp

@@ -1,6 +1,9 @@
 #include <boost/config.hpp>
 
-#if !defined(BOOST_NO_CXX11_HDR_TUPLE) && !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
+// libstdc++ from gcc 4.4 has a broken std::tuple that cannot be constructed from a compatible tuple,
+// e.g. std::tuple<int, double> from std::tuple<int const&, double const&>.
+#if !defined(BOOST_NO_CXX11_HDR_TUPLE) && !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES) && \
+    (!defined(BOOST_LIBSTDCXX_VERSION) || BOOST_LIBSTDCXX_VERSION >= 40500)
 
 #include <tuple>
 #include <boost/fusion/adapted/std_tuple.hpp>
@@ -14,8 +17,8 @@
 #else
 
 int main()
- {
- return 0;
- }
+{
+    return 0;
+}
 
 #endif