docs: updated copyright notice

GitHub Actions config

.drone.star

@@ -0,0 +1,36 @@
+# Use, modification, and distribution are
+# subject to the Boost Software License, Version 1.0. (See accompanying
+# file LICENSE.txt)
+#
+# Copyright Rene Rivera 2020.
+
+# For Drone CI we use the Starlark scripting language to reduce duplication.
+# As the yaml syntax for Drone CI is rather limited.
+#
+#
+globalenv={}
+linuxglobalimage="cppalliance/droneubuntu1604:1"
+windowsglobalimage="cppalliance/dronevs2019"
+
+def main(ctx):
+  return [
+  linux_cxx("TOOLSET=gcc COMPILER=g++ CXXSTD=03,11 Job 0", "g++", packages="", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'TOOLSET': 'gcc', 'COMPILER': 'g++', 'CXXSTD': '03,11', 'DRONE_JOB_UUID': 'b6589fc6ab'}, globalenv=globalenv),
+  linux_cxx("TOOLSET=gcc COMPILER=g++-4.7 CXXSTD=03,11 Job 1", "g++-4.7", packages="g++-4.7", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'TOOLSET': 'gcc', 'COMPILER': 'g++-4.7', 'CXXSTD': '03,11', 'DRONE_JOB_UUID': '356a192b79'}, globalenv=globalenv),
+  linux_cxx("TOOLSET=gcc COMPILER=g++-4.8 CXXSTD=03,11 Job 2", "g++-4.8", packages="g++-4.8", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'TOOLSET': 'gcc', 'COMPILER': 'g++-4.8', 'CXXSTD': '03,11', 'DRONE_JOB_UUID': 'da4b9237ba'}, globalenv=globalenv),
+  linux_cxx("TOOLSET=gcc COMPILER=g++-4.9 CXXSTD=03,11 Job 3", "g++-4.9", packages="g++-4.9", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'TOOLSET': 'gcc', 'COMPILER': 'g++-4.9', 'CXXSTD': '03,11', 'DRONE_JOB_UUID': '77de68daec'}, globalenv=globalenv),
+  linux_cxx("TOOLSET=gcc COMPILER=g++-5 CXXSTD=03,11,14,1z Job 4", "g++-5", packages="g++-5", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'TOOLSET': 'gcc', 'COMPILER': 'g++-5', 'CXXSTD': '03,11,14,1z', 'DRONE_JOB_UUID': '1b64538924'}, globalenv=globalenv),
+  linux_cxx("TOOLSET=gcc COMPILER=g++-6 CXXSTD=03,11,14,1z Job 5", "g++-6", packages="g++-6", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'TOOLSET': 'gcc', 'COMPILER': 'g++-6', 'CXXSTD': '03,11,14,1z', 'DRONE_JOB_UUID': 'ac3478d69a'}, globalenv=globalenv),
+  linux_cxx("TOOLSET=gcc COMPILER=g++-7 CXXSTD=03,11,14,17 Job 6", "g++-7", packages="g++-7", buildtype="boost", buildscript="drone", image="cppalliance/droneubuntu1404:1", environment={'TOOLSET': 'gcc', 'COMPILER': 'g++-7', 'CXXSTD': '03,11,14,17', 'DRONE_JOB_UUID': 'c1dfd96eea'}, globalenv=globalenv),
+  linux_cxx("TOOLSET=clang COMPILER=clang++ CXXSTD=03,11 Job 7", "clang++", packages="", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'TOOLSET': 'clang', 'COMPILER': 'clang++', 'CXXSTD': '03,11', 'DRONE_JOB_UUID': '902ba3cda1'}, globalenv=globalenv),
+  linux_cxx("TOOLSET=clang COMPILER=clang++-3.5 CXXSTD=03, Job 8", "clang++-3.5", packages="clang-3.5 libstdc++-4.9-dev", llvm_os="precise", llvm_ver="3.5", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'TOOLSET': 'clang', 'COMPILER': 'clang++-3.5', 'CXXSTD': '03,11,14,1z', 'DRONE_JOB_UUID': 'fe5dbbcea5'}, globalenv=globalenv),
+  linux_cxx("TOOLSET=clang COMPILER=clang++-3.6 CXXSTD=03, Job 9", "clang++-3.6", packages="clang-3.6", llvm_os="precise", llvm_ver="3.6", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'TOOLSET': 'clang', 'COMPILER': 'clang++-3.6', 'CXXSTD': '03,11,14,1z', 'DRONE_JOB_UUID': '0ade7c2cf9'}, globalenv=globalenv),
+  linux_cxx("TOOLSET=clang COMPILER=clang++-3.7 CXXSTD=03, Job 10", "clang++-3.7", packages="clang-3.7", llvm_os="precise", llvm_ver="3.7", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'TOOLSET': 'clang', 'COMPILER': 'clang++-3.7', 'CXXSTD': '03,11,14,1z', 'DRONE_JOB_UUID': 'b1d5781111'}, globalenv=globalenv),
+  linux_cxx("TOOLSET=clang COMPILER=clang++-3.8 CXXSTD=03, Job 11", "clang++-3.8", packages="clang-3.8 libstdc++-4.9-dev", llvm_os="precise", llvm_ver="3.8", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'TOOLSET': 'clang', 'COMPILER': 'clang++-3.8', 'CXXSTD': '03,11,14,1z', 'DRONE_JOB_UUID': '17ba079149'}, globalenv=globalenv),
+  linux_cxx("TOOLSET=clang COMPILER=clang++-3.9 CXXSTD=03, Job 12", "clang++-3.9", packages="clang-3.9 libstdc++-4.9-dev", llvm_os="precise", llvm_ver="3.9", buildtype="boost", buildscript="drone", image=linuxglobalimage, environment={'TOOLSET': 'clang', 'COMPILER': 'clang++-3.9', 'CXXSTD': '03,11,14,1z', 'DRONE_JOB_UUID': '7b52009b64'}, globalenv=globalenv),
+  linux_cxx("TOOLSET=clang COMPILER=clang++-4.0 CXXSTD=03, Job 13", "clang++-4.0", packages="clang-4.0", llvm_os="trusty", llvm_ver="4.0", buildtype="boost", buildscript="drone", image="cppalliance/droneubuntu1404:1", environment={'TOOLSET': 'clang', 'COMPILER': 'clang++-4.0', 'CXXSTD': '03,11,14,1z', 'DRONE_JOB_UUID': 'bd307a3ec3'}, globalenv=globalenv),
+  linux_cxx("TOOLSET=clang COMPILER=clang++-5.0 CXXSTD=03, Job 14", "clang++-5.0", packages="clang-5.0", llvm_os="trusty", llvm_ver="5.0", buildtype="boost", buildscript="drone", image="cppalliance/droneubuntu1404:1", environment={'TOOLSET': 'clang', 'COMPILER': 'clang++-5.0', 'CXXSTD': '03,11,14,1z', 'DRONE_JOB_UUID': 'fa35e19212'}, globalenv=globalenv),
+  osx_cxx("TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,1 Job 15", "clang++", packages="", buildtype="boost", buildscript="drone", environment={'TOOLSET': 'clang', 'COMPILER': 'clang++', 'CXXSTD': '03,11,14,1z', 'DRONE_JOB_UUID': 'f1abd67035'}, globalenv=globalenv),
+    ]
+
+# from https://github.com/boostorg/boost-ci
+load("@boost_ci//ci/drone/:functions.star", "linux_cxx","windows_cxx","osx_cxx","freebsd_cxx")

.drone/drone.sh

@@ -0,0 +1,37 @@
+#!/bin/bash
+
+# Copyright 2020 Rene Rivera, Sam Darwin
+# Distributed under the Boost Software License, Version 1.0.
+# (See accompanying file LICENSE.txt or copy at http://boost.org/LICENSE_1_0.txt)
+
+set -e
+export TRAVIS_BUILD_DIR=$(pwd)
+export DRONE_BUILD_DIR=$(pwd)
+export TRAVIS_BRANCH=$DRONE_BRANCH
+export VCS_COMMIT_ID=$DRONE_COMMIT
+export GIT_COMMIT=$DRONE_COMMIT
+export REPO_NAME=$DRONE_REPO
+export PATH=~/.local/bin:/usr/local/bin:$PATH
+
+if [ "$DRONE_JOB_BUILDTYPE" == "boost" ]; then
+
+echo '==================================> INSTALL'
+
+BOOST_BRANCH=develop && [ "$TRAVIS_BRANCH" == "master" ] && BOOST_BRANCH=master || true
+cd ..
+git clone -b $BOOST_BRANCH --depth 1 https://github.com/boostorg/boost.git boost-root
+cd boost-root
+git submodule update --init tools/build
+git submodule update --init libs/config
+git submodule update --init tools/boostdep
+cp -r $TRAVIS_BUILD_DIR/* libs/optional
+python tools/boostdep/depinst/depinst.py optional
+./bootstrap.sh
+./b2 headers
+
+echo '==================================> SCRIPT'
+
+echo "using $TOOLSET : : $COMPILER ;" > ~/user-config.jam
+./b2 libs/optional/test toolset=$TOOLSET cxxstd=$CXXSTD
+
+fi

.github/workflows/ci.yml

@@ -0,0 +1,377 @@
+name: GitHub Actions CI
+
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+      - develop
+      - githubactions*
+      - feature/**
+      - fix/**
+      - pr/**
+
+jobs:
+  posix:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - name: "TOOLSET=gcc COMPILER=g++ CXXSTD=03,11 Job 0"
+            buildtype: "boost"
+            packages: ""
+            packages_to_remove: ""
+            os: "ubuntu-16.04"
+            cxx: "g++"
+            sources: ""
+            llvm_os: ""
+            llvm_ver: ""
+            toolset: "gcc"
+            compiler: "g++"
+            cxxstd: "03,11"
+          - name: "TOOLSET=gcc COMPILER=g++-4.7 CXXSTD=03,11 Job 1"
+            buildtype: "boost"
+            packages: "g++-4.7"
+            packages_to_remove: ""
+            os: "ubuntu-16.04"
+            cxx: "g++-4.7"
+            sources: ""
+            llvm_os: ""
+            llvm_ver: ""
+            toolset: "gcc"
+            compiler: "g++-4.7"
+            cxxstd: "03,11"
+          - name: "TOOLSET=gcc COMPILER=g++-4.8 CXXSTD=03,11 Job 2"
+            buildtype: "boost"
+            packages: "g++-4.8"
+            packages_to_remove: ""
+            os: "ubuntu-16.04"
+            cxx: "g++-4.8"
+            sources: ""
+            llvm_os: ""
+            llvm_ver: ""
+            toolset: "gcc"
+            compiler: "g++-4.8"
+            cxxstd: "03,11"
+          - name: "TOOLSET=gcc COMPILER=g++-4.9 CXXSTD=03,11 Job 3"
+            buildtype: "boost"
+            packages: "g++-4.9"
+            packages_to_remove: ""
+            os: "ubuntu-16.04"
+            cxx: "g++-4.9"
+            sources: ""
+            llvm_os: ""
+            llvm_ver: ""
+            toolset: "gcc"
+            compiler: "g++-4.9"
+            cxxstd: "03,11"
+          - name: "TOOLSET=gcc COMPILER=g++-5 CXXSTD=03,11,14,1z Job 4"
+            buildtype: "boost"
+            packages: "g++-5"
+            packages_to_remove: ""
+            os: "ubuntu-16.04"
+            cxx: "g++-5"
+            sources: ""
+            llvm_os: ""
+            llvm_ver: ""
+            toolset: "gcc"
+            compiler: "g++-5"
+            cxxstd: "03,11,14,1z"
+          - name: "TOOLSET=gcc COMPILER=g++-6 CXXSTD=03,11,14,1z Job 5"
+            buildtype: "boost"
+            packages: "g++-6"
+            packages_to_remove: ""
+            os: "ubuntu-16.04"
+            cxx: "g++-6"
+            sources: ""
+            llvm_os: ""
+            llvm_ver: ""
+            toolset: "gcc"
+            compiler: "g++-6"
+            cxxstd: "03,11,14,1z"
+          - name: "TOOLSET=gcc COMPILER=g++-7 CXXSTD=03,11,14,17 Job 6"
+            buildtype: "boost"
+            packages: "g++-7"
+            packages_to_remove: ""
+            os: "ubuntu-16.04"
+            cxx: "g++-7"
+            sources: ""
+            llvm_os: ""
+            llvm_ver: ""
+            toolset: "gcc"
+            compiler: "g++-7"
+            cxxstd: "03,11,14,17"
+          - name: "TOOLSET=clang COMPILER=clang++ CXXSTD=03,11 Job 7"
+            buildtype: "boost"
+            packages: ""
+            packages_to_remove: ""
+            os: "ubuntu-16.04"
+            cxx: "clang++"
+            sources: ""
+            llvm_os: ""
+            llvm_ver: ""
+            toolset: "clang"
+            compiler: "clang++"
+            cxxstd: "03,11"
+          - name: "TOOLSET=clang COMPILER=clang++-3.5 CXXSTD=03, Job 8"
+            buildtype: "boost"
+            packages: "clang-3.5 libstdc++-4.9-dev"
+            packages_to_remove: ""
+            os: "ubuntu-16.04"
+            cxx: "clang++-3.5"
+            sources: ""
+            llvm_os: "precise"
+            llvm_ver: "3.5"
+            toolset: "clang"
+            compiler: "clang++-3.5"
+            cxxstd: "03,11,14"
+          - name: "TOOLSET=clang COMPILER=clang++-3.6 CXXSTD=03, Job 9"
+            buildtype: "boost"
+            packages: "clang-3.6"
+            packages_to_remove: ""
+            os: "ubuntu-16.04"
+            cxx: "clang++-3.6"
+            sources: ""
+            llvm_os: "precise"
+            llvm_ver: "3.6"
+            toolset: "clang"
+            compiler: "clang++-3.6"
+            cxxstd: "03,11,14"
+          - name: "TOOLSET=clang COMPILER=clang++-3.7 CXXSTD=03, Job 10"
+            buildtype: "boost"
+            packages: "clang-3.7"
+            packages_to_remove: ""
+            os: "ubuntu-16.04"
+            cxx: "clang++-3.7"
+            sources: ""
+            llvm_os: "precise"
+            llvm_ver: "3.7"
+            toolset: "clang"
+            compiler: "clang++-3.7"
+            cxxstd: "03,11,14"
+          - name: "TOOLSET=clang COMPILER=clang++-3.8 CXXSTD=03, Job 11"
+            buildtype: "boost"
+            packages: "clang-3.8 libstdc++-4.9-dev"
+            packages_to_remove: ""
+            os: "ubuntu-16.04"
+            cxx: "clang++-3.8"
+            sources: ""
+            llvm_os: "precise"
+            llvm_ver: "3.8"
+            toolset: "clang"
+            compiler: "clang++-3.8"
+            cxxstd: "03,11,14"
+          - name: "TOOLSET=clang COMPILER=clang++-3.9 CXXSTD=03, Job 12"
+            buildtype: "boost"
+            packages: "clang-3.9 libstdc++-4.9-dev"
+            packages_to_remove: ""
+            os: "ubuntu-16.04"
+            cxx: "clang++-3.9"
+            sources: ""
+            llvm_os: "precise"
+            llvm_ver: "3.9"
+            toolset: "clang"
+            compiler: "clang++-3.9"
+            cxxstd: "03,11,14"
+          - name: "TOOLSET=clang COMPILER=clang++-4.0 CXXSTD=03, Job 13"
+            buildtype: "boost"
+            packages: "clang-4.0"
+            packages_to_remove: ""
+            os: "ubuntu-16.04"
+            container: "ubuntu:14.04"
+            cxx: "clang++-4.0"
+            sources: ""
+            llvm_os: "trusty"
+            llvm_ver: "4.0"
+            toolset: "clang"
+            compiler: "clang++-4.0"
+            cxxstd: "03,11,14"
+          - name: "TOOLSET=clang COMPILER=clang++-5.0 CXXSTD=03, Job 14"
+            buildtype: "boost"
+            packages: "clang-5.0"
+            packages_to_remove: ""
+            os: "ubuntu-16.04"
+            container: "ubuntu:14.04"
+            cxx: "clang++-5.0"
+            sources: ""
+            llvm_os: "trusty"
+            llvm_ver: "5.0"
+            toolset: "clang"
+            compiler: "clang++-5.0"
+            cxxstd: "03,11,14,1z"
+
+    runs-on: ${{ matrix.os }}
+    container: ${{ matrix.container }}
+
+    steps:
+      - name: Check if running in container
+        if: matrix.container != ''
+        run: echo "GHA_CONTAINER=${{ matrix.container }}" >> $GITHUB_ENV
+      - name: If running in container, upgrade packages
+        if: matrix.container != ''
+        run: |
+            sudo apt-get -o Acquire::Retries=3 update && DEBIAN_FRONTEND=noninteractive apt-get -y install tzdata && apt-get -o Acquire::Retries=3 install -y sudo software-properties-common wget curl apt-transport-https make apt-file sudo unzip libssl-dev build-essential autotools-dev autoconf automake g++ libc++-helpers python python-pip ruby cpio gcc-multilib g++-multilib pkgconf python3 python3-pip ccache libpython-dev
+            sudo apt-add-repository ppa:git-core/ppa
+            sudo apt-get -o Acquire::Retries=3 update && apt-get -o Acquire::Retries=3 -y install git
+            sudo python -m pip install --upgrade pip==20.3.4
+            sudo /usr/local/bin/pip install cmake
+
+      - uses: actions/checkout@v2
+
+      - name: linux
+        shell: bash
+        env:
+          CXX: ${{ matrix.cxx }}
+          SOURCES: ${{ matrix.sources }}
+          LLVM_OS: ${{ matrix.llvm_os }}
+          LLVM_VER: ${{ matrix.llvm_ver }}
+          PACKAGES: ${{ matrix.packages }}
+          PACKAGES_TO_REMOVE: ${{ matrix.packages_to_remove }}
+          JOB_BUILDTYPE: ${{ matrix.buildtype }}
+          TOOLSET: ${{ matrix.toolset }}
+          COMPILER: ${{ matrix.compiler }}
+          CXXSTD: ${{ matrix.cxxstd }}
+          TRAVIS_BRANCH: ${{ github.base_ref }}
+          TRAVIS_OS_NAME: "linux"
+        run: |
+          echo '==================================> SETUP'
+          echo '==================================> PACKAGES'
+          set -e
+          if [ -n "$PACKAGES_TO_REMOVE" ]; then sudo apt-get purge -y $PACKAGES_TO_REMOVE; fi
+          echo ">>>>> APT: REPO.."
+          for i in {1..3}; do sudo -E apt-add-repository -y "ppa:ubuntu-toolchain-r/test" && break || sleep 2; done
+          
+          if test -n "${LLVM_OS}" ; then
+              wget -O - https://apt.llvm.org/llvm-snapshot.gpg.key | sudo apt-key add -
+              if test -n "${LLVM_VER}" ; then
+                  sudo -E apt-add-repository "deb http://apt.llvm.org/${LLVM_OS}/ llvm-toolchain-${LLVM_OS}-${LLVM_VER} main"
+              else
+                  # Snapshot (i.e. trunk) build of clang
+                  sudo -E apt-add-repository "deb http://apt.llvm.org/${LLVM_OS}/ llvm-toolchain-${LLVM_OS} main"
+              fi
+          fi
+          echo ">>>>> APT: UPDATE.."
+          sudo -E apt-get -o Acquire::Retries=3 update
+          if test -n "${SOURCES}" ; then
+              echo ">>>>> APT: INSTALL SOURCES.."
+              for SOURCE in $SOURCES; do
+                  sudo -E apt-add-repository ppa:$SOURCE
+              done
+          fi
+          echo ">>>>> APT: INSTALL ${PACKAGES}.."
+          sudo -E DEBIAN_FRONTEND=noninteractive apt-get -o Acquire::Retries=3 -y --no-install-suggests --no-install-recommends install ${PACKAGES}
+
+          echo '==================================> INSTALL AND COMPILE'
+          set -e
+          export TRAVIS_BUILD_DIR=$(pwd)
+          export TRAVIS_BRANCH=${TRAVIS_BRANCH:-$(echo $GITHUB_REF | awk 'BEGIN { FS = "/" } ; { print $3 }')}
+          export VCS_COMMIT_ID=$GITHUB_SHA
+          export GIT_COMMIT=$GITHUB_SHA
+          export REPO_NAME=$(basename $GITHUB_REPOSITORY)
+          export USER=$(whoami)
+          export CC=${CC:-gcc}
+          export PATH=~/.local/bin:/usr/local/bin:$PATH
+
+          if [ "$JOB_BUILDTYPE" == "boost" ]; then
+
+          echo '==================================> INSTALL'
+
+          BOOST_BRANCH=develop && [ "$TRAVIS_BRANCH" == "master" ] && BOOST_BRANCH=master || true
+          cd ..
+          git clone -b $BOOST_BRANCH --depth 1 https://github.com/boostorg/boost.git boost-root
+          cd boost-root
+          git submodule update --init tools/build
+          git submodule update --init libs/config
+          git submodule update --init tools/boostdep
+          cp -r $TRAVIS_BUILD_DIR/* libs/optional
+          python tools/boostdep/depinst/depinst.py optional
+          ./bootstrap.sh
+          ./b2 headers
+
+          echo '==================================> SCRIPT'
+
+          echo "using $TOOLSET : : $COMPILER ;" > ~/user-config.jam
+          ./b2 libs/optional/test toolset=$TOOLSET cxxstd=$CXXSTD
+
+          fi
+  osx:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - name: "TOOLSET=clang COMPILER=clang++ CXXSTD=03,11,1 Job 15"
+            buildtype: "boost"
+            packages: ""
+            os: "macos-10.15"
+            cxx: "clang++"
+            sources: ""
+            llvm_os: ""
+            llvm_ver: ""
+            xcode_version: 11.7
+            toolset: "clang"
+            compiler: "clang++"
+            cxxstd: "03,11,14,1z"
+
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Set DEVELOPER_DIR
+        if: matrix.xcode_version != ''
+        run: echo "DEVELOPER_DIR=/Applications/Xcode_${{ matrix.xcode_version }}.app/Contents/Developer" >> $GITHUB_ENV
+      - name: Test DEVELOPER_DIR
+        run: echo $DEVELOPER_DIR
+
+      - name: "osx"
+        shell: bash
+        env:
+          CXX: ${{ matrix.cxx }}
+          SOURCES: ${{ matrix.sources }}
+          LLVM_OS: ${{ matrix.llvm_os }}
+          LLVM_VER: ${{ matrix.llvm_ver }}
+          PACKAGES: ${{ matrix.packages }}
+          JOB_BUILDTYPE: ${{ matrix.buildtype }}
+          TOOLSET: ${{ matrix.toolset }}
+          COMPILER: ${{ matrix.compiler }}
+          CXXSTD: ${{ matrix.cxxstd }}
+          TRAVIS_BRANCH: ${{ github.base_ref }}
+          TRAVIS_OS_NAME: "osx"
+        run: |
+          echo '==================================> SETUP'
+          set -e
+          sudo mv /Library/Developer/CommandLineTools /Library/Developer/CommandLineTools.bck
+          echo '==================================> PACKAGES'
+          echo '==================================> INSTALL AND COMPILE'
+          set -e
+          export TRAVIS_BUILD_DIR=$(pwd)
+          export TRAVIS_BRANCH=${TRAVIS_BRANCH:-$(echo $GITHUB_REF | awk 'BEGIN { FS = "/" } ; { print $3 }')}
+          export VCS_COMMIT_ID=$GITHUB_SHA
+          export GIT_COMMIT=$GITHUB_SHA
+          export REPO_NAME=$(basename $GITHUB_REPOSITORY)
+          export USER=$(whoami)
+          export CC=${CC:-gcc}
+          export PATH=~/.local/bin:/usr/local/bin:$PATH
+
+          if [ "$JOB_BUILDTYPE" == "boost" ]; then
+
+          echo '==================================> INSTALL'
+
+          BOOST_BRANCH=develop && [ "$TRAVIS_BRANCH" == "master" ] && BOOST_BRANCH=master || true
+          cd ..
+          git clone -b $BOOST_BRANCH --depth 1 https://github.com/boostorg/boost.git boost-root
+          cd boost-root
+          git submodule update --init tools/build
+          git submodule update --init libs/config
+          git submodule update --init tools/boostdep
+          cp -r $TRAVIS_BUILD_DIR/* libs/optional
+          python tools/boostdep/depinst/depinst.py optional
+          ./bootstrap.sh
+          ./b2 headers
+
+          echo '==================================> SCRIPT'
+
+          echo "using $TOOLSET : : $COMPILER ;" > ~/user-config.jam
+          ./b2 libs/optional/test toolset=$TOOLSET cxxstd=$CXXSTD
+
+          fi

.travis.yml

@@ -151,6 +151,7 @@ matrix:
             - llvm-toolchain-precise-3.9
 
     - os: linux
+      dist: trusty
       compiler: clang++-4.0
       env: TOOLSET=clang COMPILER=clang++-4.0 CXXSTD=03,11,14,1z
       addons:
@@ -162,6 +163,7 @@ matrix:
             - llvm-toolchain-trusty-4.0
 
     - os: linux
+      dist: trusty
       compiler: clang++-5.0
       env: TOOLSET=clang COMPILER=clang++-5.0 CXXSTD=03,11,14,1z
       addons:

CMakeLists.txt

@@ -0,0 +1,28 @@
+# 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
+#
+# NOTE: CMake support for Boost.Optional is currently experimental at best
+#       and the interface is likely to change in the future
+
+cmake_minimum_required( VERSION 3.5 )
+project( BoostOptional )
+
+add_library( boost_optional INTERFACE )
+add_library( Boost::optional ALIAS boost_optional )
+
+target_include_directories( boost_optional INTERFACE include )
+
+target_link_libraries( boost_optional
+    INTERFACE
+        Boost::assert
+        Boost::config
+        Boost::core
+        Boost::detail
+        Boost::move
+        Boost::predef
+        Boost::static_assert
+        Boost::throw_exception
+        Boost::type_traits
+        Boost::utility
+)

doc/00_optional.qbk

@@ -2,7 +2,7 @@
     [quickbook 1.4]
     [authors [Cacciola Carballal, Fernando Luis]]
     [copyright 2003-2007 Fernando Luis Cacciola Carballal]
-    [copyright 2014-2018 Andrzej Krzemieński]
+    [copyright 2014-2021 Andrzej Krzemieński]
     [category miscellaneous]
     [id optional]
     [dirname optional]
@@ -61,7 +61,7 @@ Suppose we want to read a parameter form a config file which represents some int
 This is how you solve it with `boost::optional`:
 
     #include <boost/optional.hpp>
-    
+
     boost::optional<int> getConfigParam(std::string name);  // return either an int or a `not-an-int`
 
     int main()
@@ -71,7 +71,7 @@ This is how you solve it with `boost::optional`:
       else
         runWithNoMax();
     }
- 
+
 [endsect]
 
 [include 01_quick_start.qbk]
@@ -102,5 +102,3 @@ This is how you solve it with `boost::optional`:
 [include 90_dependencies.qbk]
 [include 91_relnotes.qbk]
 [include 92_acknowledgments.qbk]
-
-

doc/21_ref_none.qbk

@@ -17,8 +17,8 @@ namespace boost {
 
 class none_t {/* see below */};
 
-const none_t none (/* see below */); 
-    
+inline constexpr none_t none (/* see below */);
+
 } // namespace boost
 ```
 

doc/27_ref_optional_synopsis.qbk

@@ -196,11 +196,10 @@ They are empty, trivially copyable classes with disabled default constructor.
 
         bool operator!() const noexcept ; ``[link reference_optional_operator_not __GO_TO__]``
 
-        // deprecated methods
-
-        // (deprecated)
         void reset() noexcept ; ``[link reference_optional_reset __GO_TO__]``
 
+        // deprecated methods
+
         // (deprecated)
         void reset ( T const& ) ; ``[link reference_optional_reset_value __GO_TO__]``
 
@@ -275,11 +274,10 @@ They are empty, trivially copyable classes with disabled default constructor.
 
         bool operator!() const noexcept ; ``[link reference_optional_ref_operator_not __GO_TO__]``
 
-        // deprecated methods
-
-        // (deprecated)
         void reset() noexcept ; ``[link reference_optional_ref_reset __GO_TO__]``
 
+        // deprecated methods
+
         // (deprecated)
         template<class R> void reset ( R && r ) noexcept ; ``[link reference_optional_ref_reset_value __GO_TO__]``
 

doc/28_ref_optional_semantics.qbk

@@ -541,7 +541,7 @@ __SPACE__
 [#reference_optional_reset]
 
 [: `void optional<T>::reset() noexcept ;`]
-* [*Deprecated:] Same as `operator=( none_t );`
+* [*Effects:] Same as `operator=( none_t );`
 
 __SPACE__
 
@@ -1129,8 +1129,7 @@ __SPACE__
 
 [#reference_optional_ref_reset]
 [: `void optional<T&>::reset() noexcept;`]
-* [*Effects:] Use `*this = none` instead.
-* [*Remarks:] This function is depprecated.
+* [*Effects:] Same as `*this = none`.
 
 __SPACE__
 

doc/91_relnotes.qbk

@@ -1,7 +1,7 @@
 [/
     Boost.Optional
 
-    Copyright (c) 2015, 2016 Andrzej Krzemienski
+    Copyright (c) 2015 - 2018 Andrzej Krzemienski
 
     Distributed under the Boost Software License, Version 1.0.
     (See accompanying file LICENSE_1_0.txt or copy at
@@ -11,6 +11,29 @@
 
 [section:relnotes Release Notes]
 
+[heading Boost Release 1.76]
+
+* Fixed MSVC warning C4702.
+
+[heading Boost Release 1.75]
+
+* `boost::none` is `constexpr`-declared.
+
+* Fixed [@https://github.com/boostorg/optional/issues/78 issue #78].
+
+[heading Boost Release 1.73]
+
+* Fixed [@https://github.com/boostorg/optional/issues/78 issue #78].
+* `boost::none` is now declared as an inline variable (on compilers that support it): there is only one instance of `boost::none` across all translation units.
+* Fixed a number of compilation errors in GCC 4.4.7 in `optional<T>` for trivial `T`s. Thanks to Robert Leahy for the fix. For details see [@https://github.com/boostorg/optional/pull/80 pr #78].
+* Now surpressing warning `-Wweak-vtables`.
+
+[heading Boost Release 1.69]
+
+* Remove deprecation mark from `reset()` method (without arguments).
+* Fixed [@https://github.com/boostorg/optional/issues/59 issue #59].
+* Fixed bug with initialization of certain wrapper types in clang with -std=c++03. See [@https://github.com/boostorg/optional/pull/64 pr #64].
+
 [heading Boost Release 1.68]
 
 * Added member function `has_value()` for compatibility with `std::optional` ([@https://github.com/boostorg/optional/issues/52 issue #52]).

doc/html/boost_optional/acknowledgements.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Acknowledgements</title>
 <link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -116,7 +116,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/dependencies_and_portability.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Dependencies and Portability</title>
 <link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -77,7 +77,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/dependencies_and_portability/emplace_operations_in_older_compilers.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Emplace operations in older compilers</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -76,7 +76,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/dependencies_and_portability/optional_reference_binding.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Optional Reference Binding</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -93,7 +93,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/quick_start.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Quick Start</title>
 <link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -155,7 +155,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/quick_start/bypassing_unnecessary_default_construction.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Bypassing unnecessary default construction</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -61,7 +61,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/quick_start/optional_automatic_variables.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Optional automatic variables</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -61,7 +61,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/quick_start/optional_data_members.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Optional data members</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -80,7 +80,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/quick_start/storage_in_containers.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Storage in containers</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -50,7 +50,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/reference/header__boost_optional_bad_optional_access_hpp_.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Header &lt;boost/optional/bad_optional_access.hpp&gt;</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -49,7 +49,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/reference/header__boost_optional_bad_optional_access_hpp_/detailed_semantics.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Detailed semantics</title>
 <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -46,7 +46,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/reference/header__boost_optional_hpp_.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Header &lt;boost/optional.hpp&gt;</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -33,7 +33,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/reference/header__boost_optional_optional_fwd_hpp_.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Header &lt;boost/optional/optional_fwd.hpp&gt;</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -52,7 +52,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/reference/header__boost_optional_optional_hpp_/detailed_semantics___free_functions.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Detailed Semantics - Free Functions</title>
 <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -507,7 +507,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/reference/header__boost_optional_optional_hpp_/detailed_semantics___optional_references.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Detailed Semantics - Optional References</title>
 <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -486,14 +486,9 @@
 <a name="reference_optional_ref_reset"></a><div class="blockquote"><blockquote class="blockquote"><p>
             <code class="computeroutput"><span class="keyword">void</span> <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&amp;&gt;::</span><span class="identifier">reset</span><span class="special">()</span> <span class="keyword">noexcept</span><span class="special">;</span></code>
           </p></blockquote></div>
-<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
-<li class="listitem">
-              <span class="bold"><strong>Effects:</strong></span> Use <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span> <span class="special">=</span> <span class="identifier">none</span></code> instead.
-            </li>
-<li class="listitem">
-              <span class="bold"><strong>Remarks:</strong></span> This function is depprecated.
-            </li>
-</ul></div>
+<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
+              <span class="bold"><strong>Effects:</strong></span> Same as <code class="computeroutput"><span class="special">*</span><span class="keyword">this</span> <span class="special">=</span> <span class="identifier">none</span></code>.
+            </li></ul></div>
 <p>
           <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span>
         </p>
@@ -543,7 +538,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/reference/header__boost_optional_optional_hpp_/detailed_semantics___optional_values.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Detailed Semantics - Optional Values</title>
 <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -1199,8 +1199,8 @@
             <span class="special">;</span></code>
           </p></blockquote></div>
 <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
-              <span class="bold"><strong>Deprecated:</strong></span> Same as <code class="computeroutput"><span class="keyword">operator</span><span class="special">=(</span>
-              <span class="identifier">none_t</span> <span class="special">);</span></code>
+              <span class="bold"><strong>Effects:</strong></span> Same as <code class="computeroutput"><span class="keyword">operator</span><span class="special">=(</span> <span class="identifier">none_t</span>
+              <span class="special">);</span></code>
             </li></ul></div>
 <p>
           <span class="inlinemediaobject"><img src="../../../images/space.png" alt="space"></span>
@@ -1774,7 +1774,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/reference/header__boost_optional_optional_hpp_/header_optional_in_place_init.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Initialization tags</title>
 <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -47,7 +47,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/reference/header__boost_optional_optional_hpp_/header_optional_optional_refs.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Optional References</title>
 <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -84,11 +84,10 @@
 
     <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">!()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span> <span class="special">;</span> <a class="link" href="detailed_semantics___optional_references.html#reference_optional_ref_operator_not"><span class="inlinemediaobject"><img src="../../../images/callouts/R.png" alt="R"></span></a>
 
-    <span class="comment">// deprecated methods</span>
-
-    <span class="comment">// (deprecated)</span>
     <span class="keyword">void</span> <span class="identifier">reset</span><span class="special">()</span> <span class="keyword">noexcept</span> <span class="special">;</span> <a class="link" href="detailed_semantics___optional_references.html#reference_optional_ref_reset"><span class="inlinemediaobject"><img src="../../../images/callouts/R.png" alt="R"></span></a>
 
+    <span class="comment">// deprecated methods</span>
+
     <span class="comment">// (deprecated)</span>
     <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">R</span><span class="special">&gt;</span> <span class="keyword">void</span> <span class="identifier">reset</span> <span class="special">(</span> <span class="identifier">R</span> <span class="special">&amp;&amp;</span> <span class="identifier">r</span> <span class="special">)</span> <span class="keyword">noexcept</span> <span class="special">;</span> <a class="link" href="detailed_semantics___optional_references.html#reference_optional_ref_reset_value"><span class="inlinemediaobject"><img src="../../../images/callouts/R.png" alt="R"></span></a>
 
@@ -105,7 +104,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/reference/header__boost_optional_optional_hpp_/header_optional_optional_values.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Optional Values</title>
 <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -122,11 +122,10 @@
 
     <span class="keyword">bool</span> <span class="keyword">operator</span><span class="special">!()</span> <span class="keyword">const</span> <span class="keyword">noexcept</span> <span class="special">;</span> <a class="link" href="detailed_semantics___optional_values.html#reference_optional_operator_not"><span class="inlinemediaobject"><img src="../../../images/callouts/R.png" alt="R"></span></a>
 
-    <span class="comment">// deprecated methods</span>
-
-    <span class="comment">// (deprecated)</span>
     <span class="keyword">void</span> <span class="identifier">reset</span><span class="special">()</span> <span class="keyword">noexcept</span> <span class="special">;</span> <a class="link" href="detailed_semantics___optional_values.html#reference_optional_reset"><span class="inlinemediaobject"><img src="../../../images/callouts/R.png" alt="R"></span></a>
 
+    <span class="comment">// deprecated methods</span>
+
     <span class="comment">// (deprecated)</span>
     <span class="keyword">void</span> <span class="identifier">reset</span> <span class="special">(</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="special">)</span> <span class="special">;</span> <a class="link" href="detailed_semantics___optional_values.html#reference_optional_reset_value"><span class="inlinemediaobject"><img src="../../../images/callouts/R.png" alt="R"></span></a>
 
@@ -140,7 +139,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/reference/io_header.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Header &lt;boost/optional/optional_io.hpp&gt;</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -58,7 +58,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/reference/io_header/io_semantics.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Detailed semantics</title>
 <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -32,7 +32,7 @@
           <span class="special">&lt;</span><span class="keyword">class</span>
           <span class="identifier">CharType</span><span class="special">,</span>
           <span class="keyword">class</span> <span class="identifier">CharTrait</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span></code>
-          <br> &#160;&#160;&#160;&#160;<code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special">&lt;</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">&gt;&amp;</span></code> <br> &#160;&#160;&#160;&#160;<code class="computeroutput"><span class="keyword">operator</span><span class="special">&lt;&lt;(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special">&lt;</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">&gt;&amp;</span>
+          <br>     <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special">&lt;</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">&gt;&amp;</span></code> <br>     <code class="computeroutput"><span class="keyword">operator</span><span class="special">&lt;&lt;(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special">&lt;</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">&gt;&amp;</span>
           <span class="identifier">out</span><span class="special">,</span>
           <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">v</span><span class="special">);</span></code>
         </p>
@@ -53,8 +53,8 @@
         </p>
 <p>
           <code class="computeroutput"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">CharType</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">CharTrait</span><span class="special">,</span>
-          <span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span></code> <br> &#160;&#160;&#160;&#160;<code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special">&lt;</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">&gt;&amp;</span></code>
-          <br> &#160;&#160;&#160;&#160;<code class="computeroutput"><span class="keyword">operator</span><span class="special">&lt;&lt;(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special">&lt;</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">&gt;&amp;</span> <span class="identifier">out</span><span class="special">,</span> <span class="identifier">none_t</span><span class="special">);</span></code>
+          <span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span></code> <br>     <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special">&lt;</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">&gt;&amp;</span></code>
+          <br>     <code class="computeroutput"><span class="keyword">operator</span><span class="special">&lt;&lt;(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special">&lt;</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">&gt;&amp;</span> <span class="identifier">out</span><span class="special">,</span> <span class="identifier">none_t</span><span class="special">);</span></code>
         </p>
 <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
 <li class="listitem">
@@ -70,8 +70,8 @@
         </p>
 <p>
           <code class="computeroutput"><span class="keyword">template</span> <span class="special">&lt;</span><span class="keyword">class</span> <span class="identifier">CharType</span><span class="special">,</span> <span class="keyword">class</span> <span class="identifier">CharTrait</span><span class="special">,</span>
-          <span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span></code> <br> &#160;&#160;&#160;&#160;<code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special">&lt;</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">&gt;&amp;</span></code>
-          <br> &#160;&#160;&#160;&#160;<code class="computeroutput"><span class="keyword">operator</span><span class="special">&gt;&gt;(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_istream</span><span class="special">&lt;</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">&gt;&amp;</span> <span class="identifier">in</span><span class="special">,</span> <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;&amp;</span> <span class="identifier">v</span><span class="special">);</span></code>
+          <span class="keyword">class</span> <span class="identifier">T</span><span class="special">&gt;</span></code> <br>     <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_ostream</span><span class="special">&lt;</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">&gt;&amp;</span></code>
+          <br>     <code class="computeroutput"><span class="keyword">operator</span><span class="special">&gt;&gt;(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_istream</span><span class="special">&lt;</span><span class="identifier">CharType</span><span class="special">,</span> <span class="identifier">CharTrait</span><span class="special">&gt;&amp;</span> <span class="identifier">in</span><span class="special">,</span> <span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;&amp;</span> <span class="identifier">v</span><span class="special">);</span></code>
         </p>
 <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
 <li class="listitem">
@@ -98,7 +98,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/relnotes.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Release Notes</title>
 <link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -28,6 +28,69 @@
 </h2></div></div></div>
 <h4>
 <a name="boost_optional.relnotes.h0"></a>
+      <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_76"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_76">Boost
+      Release 1.76</a>
+    </h4>
+<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
+          Fixed MSVC warning C4702.
+        </li></ul></div>
+<h4>
+<a name="boost_optional.relnotes.h1"></a>
+      <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_75"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_75">Boost
+      Release 1.75</a>
+    </h4>
+<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
+<li class="listitem">
+          <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">none</span></code> is <code class="computeroutput"><span class="keyword">constexpr</span></code>-declared.
+        </li>
+<li class="listitem">
+          Fixed <a href="https://github.com/boostorg/optional/issues/78" target="_top">issue
+          #78</a>.
+        </li>
+</ul></div>
+<h4>
+<a name="boost_optional.relnotes.h2"></a>
+      <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_73"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_73">Boost
+      Release 1.73</a>
+    </h4>
+<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
+<li class="listitem">
+          Fixed <a href="https://github.com/boostorg/optional/issues/78" target="_top">issue
+          #78</a>.
+        </li>
+<li class="listitem">
+          <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">none</span></code> is now declared as an inline variable
+          (on compilers that support it): there is only one instance of <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">none</span></code> across all translation units.
+        </li>
+<li class="listitem">
+          Fixed a number of compilation errors in GCC 4.4.7 in <code class="computeroutput"><span class="identifier">optional</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&gt;</span></code> for trivial <code class="computeroutput"><span class="identifier">T</span></code>s.
+          Thanks to Robert Leahy for the fix. For details see <a href="https://github.com/boostorg/optional/pull/80" target="_top">pr
+          #78</a>.
+        </li>
+<li class="listitem">
+          Now surpressing warning <code class="computeroutput"><span class="special">-</span><span class="identifier">Wweak</span><span class="special">-</span><span class="identifier">vtables</span></code>.
+        </li>
+</ul></div>
+<h4>
+<a name="boost_optional.relnotes.h3"></a>
+      <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_69"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_69">Boost
+      Release 1.69</a>
+    </h4>
+<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
+<li class="listitem">
+          Remove deprecation mark from <code class="computeroutput"><span class="identifier">reset</span><span class="special">()</span></code> method (without arguments).
+        </li>
+<li class="listitem">
+          Fixed <a href="https://github.com/boostorg/optional/issues/59" target="_top">issue
+          #59</a>.
+        </li>
+<li class="listitem">
+          Fixed bug with initialization of certain wrapper types in clang with -std=c++03.
+          See <a href="https://github.com/boostorg/optional/pull/64" target="_top">pr #64</a>.
+        </li>
+</ul></div>
+<h4>
+<a name="boost_optional.relnotes.h4"></a>
       <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_68"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_68">Boost
       Release 1.68</a>
     </h4>
@@ -44,7 +107,7 @@
         </li>
 </ul></div>
 <h4>
-<a name="boost_optional.relnotes.h1"></a>
+<a name="boost_optional.relnotes.h5"></a>
       <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_67"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_67">Boost
       Release 1.67</a>
     </h4>
@@ -58,7 +121,7 @@
         </li>
 </ul></div>
 <h4>
-<a name="boost_optional.relnotes.h2"></a>
+<a name="boost_optional.relnotes.h6"></a>
       <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_66"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_66">Boost
       Release 1.66</a>
     </h4>
@@ -76,7 +139,7 @@
         </li>
 </ul></div>
 <h4>
-<a name="boost_optional.relnotes.h3"></a>
+<a name="boost_optional.relnotes.h7"></a>
       <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_63"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_63">Boost
       Release 1.63</a>
     </h4>
@@ -100,7 +163,7 @@
         </li>
 </ul></div>
 <h4>
-<a name="boost_optional.relnotes.h4"></a>
+<a name="boost_optional.relnotes.h8"></a>
       <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_62"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_62">Boost
       Release 1.62</a>
     </h4>
@@ -108,7 +171,7 @@
           Fixed <a href="https://svn.boost.org/trac/boost/ticket/12179" target="_top">Trac #12179</a>.
         </li></ul></div>
 <h4>
-<a name="boost_optional.relnotes.h5"></a>
+<a name="boost_optional.relnotes.h9"></a>
       <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_61"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_61">Boost
       Release 1.61</a>
     </h4>
@@ -151,7 +214,7 @@
         </li>
 </ul></div>
 <h4>
-<a name="boost_optional.relnotes.h6"></a>
+<a name="boost_optional.relnotes.h10"></a>
       <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_60"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_60">Boost
       Release 1.60</a>
     </h4>
@@ -162,7 +225,7 @@
           #11203</a>.
         </li></ul></div>
 <h4>
-<a name="boost_optional.relnotes.h7"></a>
+<a name="boost_optional.relnotes.h11"></a>
       <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_59"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_59">Boost
       Release 1.59</a>
     </h4>
@@ -176,7 +239,7 @@
         </li>
 </ul></div>
 <h4>
-<a name="boost_optional.relnotes.h8"></a>
+<a name="boost_optional.relnotes.h12"></a>
       <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_58"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_58">Boost
       Release 1.58</a>
     </h4>
@@ -212,7 +275,7 @@
         </li>
 </ul></div>
 <h4>
-<a name="boost_optional.relnotes.h9"></a>
+<a name="boost_optional.relnotes.h13"></a>
       <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_57"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_57">Boost
       Release 1.57</a>
     </h4>
@@ -222,7 +285,7 @@
           to fix C++03 compile error on <code class="computeroutput"><span class="identifier">logic_error</span><span class="special">(</span><span class="string">"..."</span><span class="special">)</span></code>"</em></span>.
         </li></ul></div>
 <h4>
-<a name="boost_optional.relnotes.h10"></a>
+<a name="boost_optional.relnotes.h14"></a>
       <span class="phrase"><a name="boost_optional.relnotes.boost_release_1_56"></a></span><a class="link" href="relnotes.html#boost_optional.relnotes.boost_release_1_56">Boost
       Release 1.56</a>
     </h4>
@@ -279,7 +342,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/tutorial/design_overview.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Design Overview</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -65,8 +65,8 @@
           <code class="computeroutput"><span class="identifier">npos</span></code>, -1, etc... This is
           equivalent to adding the special value to the set of possible values of
           a given type. This super set of <code class="computeroutput"><span class="identifier">T</span></code>
-          plus some <span class="emphasis"><em>nil_t</em></span>&#8212;where <code class="computeroutput"><span class="identifier">nil_t</span></code>
-          is some stateless POD&#8212;can be modeled in modern languages as a <span class="bold"><strong>discriminated union</strong></span> of T and nil_t. Discriminated
+          plus some <span class="emphasis"><em>nil_t</em></span>—where <code class="computeroutput"><span class="identifier">nil_t</span></code>
+          is some stateless POD—can be modeled in modern languages as a <span class="bold"><strong>discriminated union</strong></span> of T and nil_t. Discriminated
           unions are often called <span class="emphasis"><em>variants</em></span>. A variant has a
           <span class="emphasis"><em>current type</em></span>, which in our case is either <code class="computeroutput"><span class="identifier">T</span></code> or <code class="computeroutput"><span class="identifier">nil_t</span></code>.
           Using the <a href="../../../../../variant/index.html" target="_top">Boost.Variant</a>
@@ -100,8 +100,8 @@
         </p>
 <p>
           In any event, both the discriminated-union or the single-element container
-          models serve as a conceptual ground for a class representing optional&#8212;i.e.
-          possibly uninitialized&#8212;objects. For instance, these models show the
+          models serve as a conceptual ground for a class representing optional—i.e.
+          possibly uninitialized—objects. For instance, these models show the
           <span class="emphasis"><em>exact</em></span> semantics required for a wrapper of optional
           values:
         </p>
@@ -170,7 +170,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/tutorial/design_overview/the_interface.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>The Interface</title>
 <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -79,7 +79,7 @@
           facto</em></span> standard for handling optional objects because all you
           have to do to refer to a value which you don't really have is to use a
           null pointer value of the appropriate type. Pointers have been used for
-          decades&#8212;from the days of C APIs to modern C++ libraries&#8212;to <span class="emphasis"><em>refer</em></span>
+          decades—from the days of C APIs to modern C++ libraries—to <span class="emphasis"><em>refer</em></span>
           to optional (that is, possibly nonexistent) objects; particularly as optional
           arguments to a function, but also quite often as optional data members.
         </p>
@@ -93,7 +93,7 @@
           and this information is tied to the <span class="emphasis"><em>syntax</em></span> of the
           expressions. That is, the presence of operators <code class="computeroutput"><span class="special">*</span></code>
           and <code class="computeroutput"><span class="special">-&gt;</span></code> tell by themselves
-          &#8212;without any additional context&#8212; that the expression will be undefined
+          —without any additional context— that the expression will be undefined
           unless the implied pointee actually exist.
         </p>
 <p>
@@ -173,7 +173,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/tutorial/design_overview/the_semantics.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>The semantics</title>
 <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -107,7 +107,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/tutorial/exception_safety_guarantees.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Exception Safety Guarantees</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -161,7 +161,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/tutorial/gotchas.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Gotchas</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -37,7 +37,7 @@
         </p>
 <p>
           First, it is functionally similar to a tristate boolean (false, maybe,
-          true) &#8212;such as <a href="../../../../../../doc/html/tribool.html" target="_top">boost::tribool</a>&#8212;
+          true) —such as <a href="../../../../../../doc/html/tribool.html" target="_top">boost::tribool</a>—
           except that in a tristate boolean, the maybe state <span class="underline">represents
           a valid value</span>, unlike the corresponding state of an uninitialized
           <code class="computeroutput"><span class="identifier">optional</span><span class="special">&lt;</span><span class="keyword">bool</span><span class="special">&gt;</span></code>.
@@ -98,7 +98,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/tutorial/gotchas/false_positive_with__wmaybe_uninitialized.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>False positive with -Wmaybe-uninitialized</title>
 <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -63,7 +63,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/tutorial/gotchas/mixed_relational_comparisons.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Mixed relational comparisons</title>
 <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -45,7 +45,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/tutorial/gotchas/moved_from__optional_.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Moved-from optional</title>
 <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -49,7 +49,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/tutorial/in_place_factories.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>In-Place Factories</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -183,7 +183,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/tutorial/io_operators.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>IO operators</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -73,7 +73,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/tutorial/optional_references.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Optional references</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -103,7 +103,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/tutorial/optional_references/rebinding_semantics_for_assignment_of_optional_references.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Rebinding semantics for assignment of optional references</title>
 <link rel="stylesheet" href="../../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -133,7 +133,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/tutorial/performance_considerations.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Performance considerations</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -251,7 +251,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/tutorial/relational_operators.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Relational operators</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -99,7 +99,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/tutorial/type_requirements.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Type requirements</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -95,7 +95,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/boost_optional/tutorial/when_to_use_optional.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>When to use Optional</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -128,7 +128,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/index.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Boost.Optional</title>
 <link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -25,8 +25,8 @@
 <div><div class="author"><h3 class="author">
 <span class="firstname">Fernando Luis</span> <span class="surname">Cacciola Carballal</span>
 </h3></div></div>
-<div><p class="copyright">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal</p></div>
-<div><p class="copyright">Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski</p></div>
+<div><p class="copyright">Copyright © 2003-2007 Fernando Luis Cacciola Carballal</p></div>
+<div><p class="copyright">Copyright © 2014-2021 Andrzej Krzemieński</p></div>
 <div><div class="legalnotice">
 <a name="optional.legal"></a><p>
         Distributed under the Boost Software License, Version 1.0. (See accompanying
@@ -145,7 +145,7 @@
 </div>
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
-<td align="left"><p><small>Last revised: July 02, 2018 at 21:10:01 GMT</small></p></td>
+<td align="left"><p><small>Last revised: March 10, 2021 at 22:06:01 GMT</small></p></td>
 <td align="right"><div class="copyright-footer"></div></td>
 </tr></table>
 <hr>

doc/html/optional/reference.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Reference</title>
 <link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -54,7 +54,7 @@
 
 <span class="keyword">class</span> <span class="identifier">none_t</span> <span class="special">{/*</span> <span class="identifier">see</span> <span class="identifier">below</span> <span class="special">*/};</span>
 
-<span class="keyword">const</span> <span class="identifier">none_t</span> <span class="identifier">none</span> <span class="special">(/*</span> <span class="identifier">see</span> <span class="identifier">below</span> <span class="special">*/);</span>
+<span class="keyword">inline</span> <span class="keyword">constexpr</span> <span class="identifier">none_t</span> <span class="identifier">none</span> <span class="special">(/*</span> <span class="identifier">see</span> <span class="identifier">below</span> <span class="special">*/);</span>
 
 <span class="special">}</span> <span class="comment">// namespace boost</span>
 </pre>
@@ -75,7 +75,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/optional/reference/header__boost_optional_optional_hpp_.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Header &lt;boost/optional/optional.hpp&gt;</title>
 <link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -97,7 +97,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

doc/html/optional/tutorial.html

@@ -1,6 +1,6 @@
 <html>
 <head>
-<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
+<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
 <title>Tutorial</title>
 <link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css">
 <meta name="generator" content="DocBook XSL Stylesheets Vsnapshot">
@@ -139,7 +139,7 @@
 </div>
 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 <td align="left"></td>
-<td align="right"><div class="copyright-footer">Copyright &#169; 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright &#169; 2014-2018 Andrzej Krzemie&#324;ski<p>
+<td align="right"><div class="copyright-footer">Copyright © 2003-2007 Fernando Luis Cacciola Carballal<br>Copyright © 2014-2021 Andrzej Krzemieński<p>
         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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
       </p>

include/boost/none.hpp

@@ -13,6 +13,7 @@
 #ifndef BOOST_NONE_17SEP2003_HPP
 #define BOOST_NONE_17SEP2003_HPP
 
+#include "boost/config.hpp"
 #include "boost/none_t.hpp"
 
 // NOTE: Borland users have to include this header outside any precompiled headers
@@ -23,7 +24,7 @@ namespace boost {
 
 #ifdef BOOST_OPTIONAL_USE_OLD_DEFINITION_OF_NONE
 
-none_t const none = (static_cast<none_t>(0)) ;
+BOOST_INLINE_VARIABLE none_t BOOST_CONSTEXPR_OR_CONST none = (static_cast<none_t>(0)) ;
 
 #elif defined BOOST_OPTIONAL_USE_SINGLETON_DEFINITION_OF_NONE
 
@@ -35,7 +36,7 @@ namespace detail { namespace optional_detail {
   {
     static const T instance;
   };
-  
+
   template <typename T>
   const T none_instance<T>::instance = T(); // global, but because 'tis a template, no cpp file required
 
@@ -44,16 +45,15 @@ namespace detail { namespace optional_detail {
 
 namespace {
   // TU-local
-  const none_t& none = detail::optional_detail::none_instance<none_t>::instance; 
+  const none_t& none = detail::optional_detail::none_instance<none_t>::instance;
 }
 
 #else
 
-const none_t none ((none_t::init_tag()));
+BOOST_INLINE_VARIABLE BOOST_CONSTEXPR_OR_CONST none_t none ((none_t::init_tag()));
 
 #endif // older definitions
 
 } // namespace boost
 
 #endif // header guard
-

include/boost/none_t.hpp

@@ -13,6 +13,8 @@
 #ifndef BOOST_NONE_T_17SEP2003_HPP
 #define BOOST_NONE_T_17SEP2003_HPP
 
+#include <boost/config.hpp>
+
 namespace boost {
 
 #ifdef BOOST_OPTIONAL_USE_OLD_DEFINITION_OF_NONE
@@ -29,7 +31,7 @@ class none_t {};
 struct none_t
 {
   struct init_tag{};
-  explicit none_t(init_tag){} // to disable default constructor
+  explicit BOOST_CONSTEXPR none_t(init_tag){} // to disable default constructor
 };
 
 #endif // old implementation workarounds

include/boost/optional/bad_optional_access.hpp

@@ -19,6 +19,11 @@
 
 namespace boost {
 
+#if defined(__clang__)
+# pragma clang diagnostic push
+# pragma clang diagnostic ignored "-Wweak-vtables"
+#endif
+
 class bad_optional_access : public std::logic_error
 {
 public:
@@ -27,6 +32,10 @@ public:
     {}
 };
 
+#if defined(__clang__)
+# pragma clang diagnostic pop
+#endif
+
 } // namespace boost
 
 #endif

include/boost/optional/detail/old_optional_implementation.hpp

@@ -79,7 +79,7 @@ class optional_base : public optional_tag
   private :
 
     typedef
-#if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
+#if !BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x564))
     BOOST_DEDUCED_TYPENAME
 #endif
     ::boost::detail::make_reference_content<T>::type internal_type ;
@@ -332,7 +332,7 @@ class optional_base : public optional_tag
 
   public :
 
-    // **DEPPRECATED** Destroys the current value, if any, leaving this UNINITIALIZED
+    // Destroys the current value, if any, leaving this UNINITIALIZED
     // No-throw (assuming T::~T() doesn't)
     void reset() BOOST_NOEXCEPT { destroy(); }
 
@@ -619,7 +619,7 @@ class optional_base : public optional_tag
     reference_const_type dereference( internal_type const* p, is_reference_tag     ) const { return p->get() ; }
     reference_type       dereference( internal_type*       p, is_reference_tag     )       { return p->get() ; }
 
-#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x581))
+#if BOOST_WORKAROUND(BOOST_BORLANDC, BOOST_TESTED_AT(0x581))
     void destroy_impl ( is_not_reference_tag ) { get_ptr_impl()->internal_type::~internal_type() ; m_initialized = false ; }
 #else
     void destroy_impl ( is_not_reference_tag ) { get_ptr_impl()->~T() ; m_initialized = false ; }

include/boost/optional/detail/optional_config.hpp

@@ -28,7 +28,7 @@
 # define BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
 #endif
 
-#if BOOST_WORKAROUND(__BORLANDC__, <= 0x551)
+#if BOOST_WORKAROUND(BOOST_BORLANDC, <= 0x551)
 // BCB (5.5.1) cannot parse the nested template struct in an inplace factory.
 # define BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
 #endif

include/boost/optional/detail/optional_reference_spec.hpp

@@ -151,7 +151,14 @@ public:
     T* get_ptr() const BOOST_NOEXCEPT { return ptr_; }
     T* operator->() const { BOOST_ASSERT(ptr_); return ptr_; }
     T& operator*() const { BOOST_ASSERT(ptr_); return *ptr_; }
-    T& value() const { return ptr_ ? *ptr_ : (throw_exception(bad_optional_access()), *ptr_); }
+    
+    T& value() const
+    {
+      if (this->is_initialized())
+        return this->get();
+      else
+        throw_exception(bad_optional_access());
+    }
     
     bool operator!() const BOOST_NOEXCEPT { return ptr_ == 0; }  
     BOOST_EXPLICIT_OPERATOR_BOOL_NOEXCEPT()

include/boost/optional/detail/optional_trivially_copyable_base.hpp

@@ -30,7 +30,7 @@ class tc_optional_base : public optional_tag
       :
       m_initialized(false) {}
 
-    tc_optional_base ( argument_type val )
+    tc_optional_base ( init_value_tag, argument_type val )
       :
       m_initialized(true), m_storage(val) {}
 
@@ -71,7 +71,7 @@ class tc_optional_base : public optional_tag
     // Assigns from another optional<T> (deep-copies the rhs value)
     void assign ( tc_optional_base const& rhs ) 
     {
-      this->operator=(rhs);
+      *this = rhs;
     }
 
     // Assigns from another _convertible_ optional<U> (deep-copies the rhs value)
@@ -127,7 +127,7 @@ class tc_optional_base : public optional_tag
 
   public :
 
-    // **DEPPRECATED** Destroys the current value, if any, leaving this UNINITIALIZED
+    // Destroys the current value, if any, leaving this UNINITIALIZED
     // No-throw (assuming T::~T() doesn't)
     void reset() BOOST_NOEXCEPT { destroy(); }
 
@@ -359,7 +359,7 @@ class tc_optional_base : public optional_tag
     template<class Expr>
     void construct ( Expr const& factory, in_place_factory_base const* )
      {
-       boost_optional_detail::construct<value_type>(factory, m_storage.address());
+       boost_optional_detail::construct<value_type>(factory, boost::addressof(m_storage));
        m_initialized = true ;
      }
 

include/boost/optional/optional.hpp

@@ -107,7 +107,9 @@ using optional_ns::in_place_init_if;
 
 namespace optional_detail {
 
-struct optional_tag {} ;
+struct init_value_tag {};
+
+struct optional_tag {};
 
 
 template<class T>
@@ -147,7 +149,7 @@ class optional_base : public optional_tag
 
     // Creates an optional<T> initialized with 'val'.
     // Can throw if T::T(T const&) does
-    optional_base ( argument_type val )
+    optional_base ( init_value_tag, argument_type val )
       :
       m_initialized(false)
     {
@@ -157,7 +159,7 @@ class optional_base : public optional_tag
 #ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // move-construct an optional<T> initialized from an rvalue-ref to 'val'.
     // Can throw if T::T(T&&) does
-    optional_base ( rval_reference_type val )
+    optional_base ( init_value_tag, rval_reference_type val )
       :
       m_initialized(false)
     {
@@ -378,7 +380,7 @@ class optional_base : public optional_tag
 
   public :
 
-    // **DEPPRECATED** Destroys the current value, if any, leaving this UNINITIALIZED
+    // Destroys the current value, if any, leaving this UNINITIALIZED
     // No-throw (assuming T::~T() doesn't)
     void reset() BOOST_NOEXCEPT { destroy(); }
 
@@ -775,7 +777,7 @@ class optional_base : public optional_tag
 
 #include <boost/optional/detail/optional_trivially_copyable_base.hpp>
 
-// definition of metafunciton is_optional_val_init_candidate
+// definition of metafunction is_optional_val_init_candidate
 template <typename U>
 struct is_optional_related
   : boost::conditional< boost::is_base_of<optional_detail::optional_tag, BOOST_DEDUCED_TYPENAME boost::decay<U>::type>::value
@@ -811,9 +813,14 @@ struct is_optional_constructible : boost::true_type
 
 #endif // is_convertible condition
 
-template <typename T, typename U>
+template <typename T, typename U, bool = is_optional_related<U>::value>
 struct is_optional_val_init_candidate
-  : boost::conditional< !is_optional_related<U>::value && is_convertible_to_T_or_factory<T, U>::value
+  : boost::false_type
+{};
+
+template <typename T, typename U>
+struct is_optional_val_init_candidate<T, U, false>
+  : boost::conditional< is_convertible_to_T_or_factory<T, U>::value
                       , boost::true_type, boost::false_type>::type
 {};
 
@@ -870,12 +877,12 @@ class optional
 
     // Creates an optional<T> initialized with 'val'.
     // Can throw if T::T(T const&) does
-    optional ( argument_type val ) : base(val) {}
+    optional ( argument_type val ) : base(optional_detail::init_value_tag(), val) {}
 
 #ifndef  BOOST_OPTIONAL_DETAIL_NO_RVALUE_REFERENCES
     // Creates an optional<T> initialized with 'move(val)'.
     // Can throw if T::T(T &&) does
-    optional ( rval_reference_type val ) : base( boost::forward<T>(val) )
+    optional ( rval_reference_type val ) : base(optional_detail::init_value_tag(), boost::forward<T>(val))
       {}
 #endif
 
@@ -965,7 +972,7 @@ class optional
     // Can throw if T::T(T&&) does
 
 #ifndef BOOST_OPTIONAL_DETAIL_NO_DEFAULTED_MOVE_FUNCTIONS
-    optional ( optional && rhs ) = default;
+    optional ( optional && ) = default;
 #else
     optional ( optional && rhs )
       BOOST_NOEXCEPT_IF(::boost::is_nothrow_move_constructible<T>::value)

meta/libraries.json

@@ -12,5 +12,6 @@
     "maintainers": [
         "Fernando Cacciola <fernando_cacciola -at- ciudad.com.ar>",
         "Andrzej Krzemienski <akrzemi1 -at- gmail.com>"
-    ]
+    ],
+    "cxxstd": "03"
 }

test/Jamfile.v2

@@ -18,6 +18,7 @@ import testing ;
 {
   test-suite optional :
     [ run optional_test.cpp ]
+    [ run optional_test_assign.cpp ]
     [ run optional_test_swap.cpp ]
     [ run optional_test_conversions_from_U.cpp ]
     [ run optional_test_convert_from_T.cpp ]
@@ -49,6 +50,8 @@ import testing ;
     [ run optional_test_member_T.cpp ]
     [ run optional_test_tc_base.cpp ]
     [ compile optional_test_sfinae_friendly_ctor.cpp ]
+    [ compile optional_test_path_assignment.cpp ]
+    [ compile-fail optional_test_fail_const_swap.cpp ]
     [ compile-fail optional_test_ref_convert_assign_const_int_prevented.cpp ]
     [ compile-fail optional_test_fail1.cpp ]
     [ compile-fail optional_test_fail3a.cpp ]
@@ -74,6 +77,7 @@ import testing ;
     [ run optional_test_static_properties.cpp ]
     [ compile optional_test_maybe_uninitialized_warning.cpp ]
     [ compile optional_test_deleted_default_ctor.cpp ]
+    [ compile optional_test_constructible_from_other.cpp ]
     #[ run optional_xconfig_HACK_TO_LIST_PREDEFINED_MACROS.cpp ]
     [ run optional_xconfig_NO_PROPER_ASSIGN_FROM_CONST_INT_pass.cpp ]
     [ run-fail optional_xconfig_NO_PROPER_ASSIGN_FROM_CONST_INT_fail.cpp ]

test/optional_ref_assign_test_defs.hpp

@@ -13,7 +13,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test.cpp

@@ -24,7 +24,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_assign.cpp

@@ -0,0 +1,30 @@
+// Copyright (C) 2018 Andrzej Krzemienski.
+//
+// Use, modification, and distribution is 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)
+//
+// See http://www.boost.org/lib/optional for documentation.
+//
+// You are welcome to contact the author at:
+//  akrzemi1@gmail.com
+
+#include "boost/core/lightweight_test.hpp"
+#include "boost/optional/optional.hpp"
+
+void test_assignment_to_empty()
+{
+  // this test used to fail on GCC 8.1.0/8.2.0/9.0.0 with -std=c++98
+  boost::optional<int> oa, ob(1);
+  BOOST_TEST(!oa);
+  BOOST_TEST(ob);
+
+  oa = ob;
+  BOOST_TEST(oa);
+}
+
+int main()
+{
+  test_assignment_to_empty();
+  return boost::report_errors();
+}

test/optional_test_constructible_from_other.cpp

@@ -0,0 +1,59 @@
+// Copyright (c) 2018 Andrey Semashev
+//
+// Use, modification, and distribution is 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)
+
+// The test verifies that Boost.Optional copy constructors do not attempt to invoke
+// the element type initializing constructors from templated arguments
+
+#include <boost/optional/optional.hpp>
+#include <boost/core/enable_if.hpp>
+
+struct no_type
+{
+    char data;
+};
+
+struct yes_type
+{
+    char data[2];
+};
+
+template< unsigned int Size >
+struct size_tag {};
+
+template< typename T, typename U >
+struct is_constructible
+{
+    static U& get();
+
+    template< typename T1 >
+    static yes_type check_helper(size_tag< sizeof(static_cast< T1 >(get())) >*);
+    template< typename T1 >
+    static no_type check_helper(...);
+
+    static const bool value = sizeof(check_helper< T >(0)) == sizeof(yes_type);
+};
+
+template< typename T >
+class wrapper
+{
+public:
+    wrapper() {}
+    wrapper(wrapper const&) {}
+    template< typename U >
+    wrapper(U const&, typename boost::enable_if_c< is_constructible< T, U >::value, int >::type = 0) {}
+};
+
+inline boost::optional< wrapper< int > > foo()
+{
+    return boost::optional< wrapper< int > >();
+}
+
+int main()
+{
+    // Invokes boost::optional copy constructor. Should not invoke wrapper constructor from U.
+    boost::optional< wrapper< int > > res = foo();
+    return 0;
+}

test/optional_test_conversions_from_U.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_convert_from_T.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_deleted_default_ctor.cpp

@@ -1,4 +1,6 @@
 // Copyright 2017 Peter Dimov
+// Copyright 2017 Vinnie Falco
+// Copyright 2018 Andrzej Krzemienski
 //
 // Distributed under the Boost Software License, Version 1.0.
 //
@@ -19,8 +21,8 @@ int main()
 
 class basic_multi_buffer;
 
-class const_buffers_type
-{
+class const_buffers_type // a similar declaration in boost.beast had problem
+{                        // with boost opitonal
     basic_multi_buffer const* b_;
 
     friend class basic_multi_buffer;
@@ -29,16 +31,36 @@ class const_buffers_type
     const_buffers_type(basic_multi_buffer const& b);
 
 public:
-
     const_buffers_type() = delete;
     const_buffers_type(const_buffers_type const&) = default;
     const_buffers_type& operator=(const_buffers_type const&) = default;
 };
 
+void test_beast_example()
+{
+  // test if it even compiles
+  boost::optional< std::pair<const_buffers_type, int> > opt, opt2;
+  opt = opt2;
+  (void)opt;
+}
+
+struct NotDefaultConstructible // minimal class exposing the problem
+{
+  NotDefaultConstructible() = delete;
+};
+
+void test_assign_for_non_default_constructible()
+{
+  // test if it even compiles
+  boost::optional<NotDefaultConstructible> opt, opt2;
+  opt = opt2;
+  (void)opt;
+}
+
 int main()
 {
-    boost::optional< std::pair<const_buffers_type, int> > opt, opt2;
-    opt = opt2;
+  test_beast_example();
+  test_assign_for_non_default_constructible();
 }
 
 #endif

test/optional_test_emplace.cpp

@@ -11,10 +11,11 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 
+#include <string>
 #include "boost/core/lightweight_test.hpp"
 #include "boost/none.hpp"
 

test/optional_test_empty_braces.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_equals_none.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_experimental_traits.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_fail_const_swap.cpp

@@ -0,0 +1,26 @@
+// Copyright (C) 2018, Andrzej Krzemienski.
+//
+// Use, modification, and distribution is 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)
+//
+// See http://www.boost.org/lib/optional for documentation.
+//
+// You are welcome to contact the author at:
+//  akrzemi1@gmail.com
+
+#include "boost/optional.hpp"
+
+// THIS TEST SHOULD FAIL TO COMPILE
+
+void test_converitng_assignment_of_different_enums()
+{
+  const boost::optional<int> o1(1);
+  const boost::optional<int> o2(2);
+  swap(o1, o2); // no swap on const objects should compile
+}
+
+int main()
+{
+  test_converitng_assignment_of_different_enums();
+}

test/optional_test_flat_map.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_inplace_factory.cpp

@@ -13,7 +13,7 @@
 #include<string>
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 
@@ -31,10 +31,10 @@ struct Guard
   std::string str;
   Guard() : num() {}
   Guard(double num_, std::string str_) : num(num_), str(str_) {}
-  
+
   friend bool operator==(const Guard& lhs, const Guard& rhs) { return lhs.num == rhs.num && lhs.str == rhs.str; }
   friend bool operator!=(const Guard& lhs, const Guard& rhs) { return !(lhs == rhs); }
-  
+
 private:
   Guard(const Guard&);
   Guard& operator=(const Guard&);
@@ -44,26 +44,30 @@ void test_ctor()
 {
 #ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
   Guard g0, g1(1.0, "one"), g2(2.0, "two");
-  
+
   boost::optional<Guard> og0 ( boost::in_place() );
   boost::optional<Guard> og1 ( boost::in_place(1.0, "one") );
   boost::optional<Guard> og1_( boost::in_place(1.0, "one") );
   boost::optional<Guard> og2 ( boost::in_place<Guard>(2.0, "two") );
-  
+
   BOOST_TEST(og0);
   BOOST_TEST(og1);
   BOOST_TEST(og1_);
   BOOST_TEST(og2);
-  
+
   BOOST_TEST(*og0  == g0);
   BOOST_TEST(*og1  == g1);
   BOOST_TEST(*og1_ == g1);
   BOOST_TEST(*og2  == g2);
-  
+
   BOOST_TEST(og1_ == og1);
   BOOST_TEST(og1_ != og2);
   BOOST_TEST(og1_ != og0);
-#endif 
+
+  boost::optional<unsigned int> o( boost::in_place(5) );
+  BOOST_TEST(o);
+  BOOST_TEST(*o == 5);
+#endif
 }
 
 void test_assign()
@@ -71,27 +75,32 @@ void test_assign()
 #ifndef BOOST_OPTIONAL_NO_INPLACE_FACTORY_SUPPORT
 #ifndef BOOST_OPTIONAL_WEAK_OVERLOAD_RESOLUTION
   Guard g0, g1(1.0, "one"), g2(2.0, "two");
-  
+
   boost::optional<Guard> og0, og1, og1_, og2;
-  
+
   og0  = boost::in_place();
   og1  = boost::in_place(1.0, "one");
   og1_ = boost::in_place(1.0, "one");
   og2  = boost::in_place<Guard>(2.0, "two");
-  
+
   BOOST_TEST(og0);
   BOOST_TEST(og1);
   BOOST_TEST(og1_);
   BOOST_TEST(og2);
-  
+
   BOOST_TEST(*og0  == g0);
   BOOST_TEST(*og1  == g1);
   BOOST_TEST(*og1_ == g1);
   BOOST_TEST(*og2  == g2);
-  
+
   BOOST_TEST(og1_ == og1);
   BOOST_TEST(og1_ != og2);
   BOOST_TEST(og1_ != og0);
+
+  boost::optional<unsigned int> o;
+  o = boost::in_place(5);
+  BOOST_TEST(o);
+  BOOST_TEST(*o == 5);
 #endif
 #endif
 }
@@ -101,4 +110,4 @@ int main()
   test_ctor();
   test_assign();
   return boost::report_errors();
-}
+}

test/optional_test_inplace_fail.cpp

@@ -13,7 +13,7 @@
 #include<string>
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_inplace_fail2.cpp

@@ -13,7 +13,7 @@
 #include<string>
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_io.cpp

@@ -14,7 +14,7 @@
 #include "boost/optional/optional.hpp"
 #include "boost/optional/optional_io.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_make_optional.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_map.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_maybe_uninitialized_warning.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_member_T.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_minimum_requirements.cpp

@@ -11,10 +11,11 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 
+#include <string>
 #include "boost/core/lightweight_test.hpp"
 #include "boost/none.hpp"
 

test/optional_test_move.cpp

@@ -12,7 +12,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_msvc_bug_workaround.cpp

@@ -12,7 +12,7 @@
 #define BOOST_OPTIONAL_CONFIG_NO_RVALUE_REFERENCES
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_noexcept_move.cpp

@@ -12,7 +12,7 @@
 #include "boost/static_assert.hpp"
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_old_impl.cpp

@@ -12,7 +12,7 @@
 #define BOOST_OPTIONAL_CONFIG_USE_OLD_IMPLEMENTATION_OF_OPTIONAL // does old implementation still work for basic usage?
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_path_assignment.cpp

@@ -0,0 +1,73 @@
+// Copyright (C) 2019 Andrzej Krzemienski.
+//
+// Use, modification, and distribution is 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)
+//
+// See http://www.boost.org/lib/optional for documentation.
+//
+// You are welcome to contact the author at:
+//  akrzemi1@gmail.com
+
+#include "boost/optional/optional.hpp"
+
+#ifdef BOOST_BORLANDC
+#pragma hdrstop
+#endif
+
+#ifndef BOOST_OPTIONAL_DETAIL_NO_IS_CONSTRUCTIBLE_TRAIT
+#ifndef BOOST_OPTIONAL_DETAIL_NO_SFINAE_FRIENDLY_CONSTRUCTORS
+template <typename, typename>
+struct void_t
+{
+  typedef void type;
+};
+
+
+template <typename T, typename = void>
+struct trait
+{
+};
+
+// the following trait emulates properties std::iterator_traits
+template <typename T>
+struct trait<T, BOOST_DEDUCED_TYPENAME void_t<BOOST_DEDUCED_TYPENAME T::value_type,
+                                              BOOST_DEDUCED_TYPENAME boost::enable_if<boost::is_constructible<T, T&> >::type
+                                             >::type>
+{
+  typedef BOOST_DEDUCED_TYPENAME T::value_type value_type;
+};
+
+// This class emulates the properties of std::filesystem::path
+struct Path
+{
+
+#if __cplusplus >= 201103
+    template <typename T, typename = BOOST_DEDUCED_TYPENAME trait<T>::value_type>
+        Path(T const&);
+#else
+  template <typename T>
+    Path(T const&, BOOST_DEDUCED_TYPENAME trait<T>::value_type* = 0);
+#endif
+
+};
+#endif
+#endif
+
+
+int main()
+{
+#ifndef BOOST_OPTIONAL_DETAIL_NO_IS_CONSTRUCTIBLE_TRAIT
+#ifndef BOOST_OPTIONAL_DETAIL_NO_SFINAE_FRIENDLY_CONSTRUCTORS
+
+    boost::optional<Path> optFs1;
+    boost::optional<Path> optFs2;
+
+    optFs1 = optFs2;
+
+    // the following still fails although it shouldn't
+    //BOOST_STATIC_ASSERT((std::is_copy_constructible<boost::optional<Path>>::value));
+
+#endif
+#endif
+}

test/optional_test_ref_assign_const_int.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_ref_assign_mutable_int.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_ref_assign_portable_minimum.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_ref_convert_assign_const_int.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_ref_convert_assign_const_int_prevented.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_ref_convert_assign_mutable_int.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_ref_convert_assign_non_int.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_ref_converting_ctor.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 
@@ -93,7 +93,9 @@ template <typename T>
 void test_all_const_cases()
 {
   test_converting_ctor<T>();
+#ifndef BOOST_OPTIONAL_CONFIG_NO_PROPER_CONVERT_FROM_CONST_INT
   test_converting_ctor<const T>();
+#endif
   test_converting_ctor_for_noconst_const<T>();
 }
 

test/optional_test_ref_move.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_ref_portable_minimum.cpp

@@ -11,7 +11,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif
 

test/optional_test_ref_to_val.cpp

@@ -12,7 +12,7 @@
 
 #include "boost/optional/optional.hpp"
 
-#ifdef __BORLANDC__
+#ifdef BOOST_BORLANDC
 #pragma hdrstop
 #endif