From 8992cd1892df1adb352cf5d5b279a00686d1e88a Mon Sep 17 00:00:00 2001 From: Jonathan Wakely Date: Mon, 6 Jul 2020 21:54:12 +0100 Subject: [PATCH] libstdc++: Add noexcept to std::optional initialization (PR 96036) libstdc++-v3/ChangeLog: PR libstdc++/96036 * include/std/optional (optional): Add noexcept-specifier to every constructor, assignment operator, emplace function and dereference operator. * testsuite/20_util/optional/assignment/noexcept.cc: New test. * testsuite/20_util/optional/cons/noexcept.cc: New test. --- libstdc++-v3/include/std/optional | 31 +++++-- .../20_util/optional/assignment/noexcept.cc | 81 +++++++++++++++++++ .../20_util/optional/cons/noexcept.cc | 64 +++++++++++++++ 3 files changed, 170 insertions(+), 6 deletions(-) create mode 100644 libstdc++-v3/testsuite/20_util/optional/assignment/noexcept.cc create mode 100644 libstdc++-v3/testsuite/20_util/optional/cons/noexcept.cc diff --git a/libstdc++-v3/include/std/optional b/libstdc++-v3/include/std/optional index 923d45ae0e8..785c434412d 100644 --- a/libstdc++-v3/include/std/optional +++ b/libstdc++-v3/include/std/optional @@ -698,6 +698,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION is_convertible<_Up&&, _Tp>> = true> constexpr optional(_Up&& __t) + noexcept(is_nothrow_constructible_v<_Tp, _Up>) : _Base(std::in_place, std::forward<_Up>(__t)) { } template>> = false> explicit constexpr optional(_Up&& __t) + noexcept(is_nothrow_constructible_v<_Tp, _Up>) : _Base(std::in_place, std::forward<_Up>(__t)) { } template>> = true> constexpr optional(const optional<_Up>& __t) + noexcept(is_nothrow_constructible_v<_Tp, const _Up&>) { if (__t) emplace(*__t); @@ -727,6 +730,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __not_<__converts_from_optional<_Tp, _Up>>> = false> explicit constexpr optional(const optional<_Up>& __t) + noexcept(is_nothrow_constructible_v<_Tp, const _Up&>) { if (__t) emplace(*__t); @@ -739,6 +743,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __not_<__converts_from_optional<_Tp, _Up>>> = true> constexpr optional(optional<_Up>&& __t) + noexcept(is_nothrow_constructible_v<_Tp, _Up>) { if (__t) emplace(std::move(*__t)); @@ -751,6 +756,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __not_<__converts_from_optional<_Tp, _Up>>> = false> explicit constexpr optional(optional<_Up>&& __t) + noexcept(is_nothrow_constructible_v<_Tp, _Up>) { if (__t) emplace(std::move(*__t)); @@ -760,6 +766,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION _Requires> = false> explicit constexpr optional(in_place_t, _Args&&... __args) + noexcept(is_nothrow_constructible_v<_Tp, _Args...>) : _Base(std::in_place, std::forward<_Args>(__args)...) { } template> = false> explicit constexpr optional(in_place_t, initializer_list<_Up> __il, _Args&&... __args) + noexcept(is_nothrow_constructible_v<_Tp, initializer_list<_Up>&, + _Args...>) : _Base(std::in_place, __il, std::forward<_Args>(__args)...) { } + // Assignment operators. optional& operator=(nullopt_t) noexcept @@ -786,6 +796,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION is_assignable<_Tp&, _Up>>, optional&> operator=(_Up&& __u) + noexcept(__and_v, + is_nothrow_assignable<_Tp&, _Up>>) { if (this->_M_is_engaged()) this->_M_get() = std::forward<_Up>(__u); @@ -803,6 +815,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __not_<__assigns_from_optional<_Tp, _Up>>>, optional&> operator=(const optional<_Up>& __u) + noexcept(__and_v, + is_nothrow_assignable<_Tp&, const _Up&>>) { if (__u) { @@ -826,6 +840,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION __not_<__assigns_from_optional<_Tp, _Up>>>, optional&> operator=(optional<_Up>&& __u) + noexcept(__and_v, + is_nothrow_assignable<_Tp&, _Up>>) { if (__u) { @@ -845,6 +861,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION template enable_if_t, _Tp&> emplace(_Args&&... __args) + noexcept(is_nothrow_constructible_v<_Tp, _Args...>) { this->_M_reset(); this->_M_construct(std::forward<_Args>(__args)...); @@ -855,6 +872,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION enable_if_t&, _Args&&...>, _Tp&> emplace(initializer_list<_Up> __il, _Args&&... __args) + noexcept(is_nothrow_constructible_v<_Tp, initializer_list<_Up>&, + _Args...>) { this->_M_reset(); this->_M_construct(__il, std::forward<_Args>(__args)...); @@ -887,27 +906,27 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION // Observers. constexpr const _Tp* - operator->() const + operator->() const noexcept { return std::__addressof(this->_M_get()); } constexpr _Tp* - operator->() + operator->() noexcept { return std::__addressof(this->_M_get()); } constexpr const _Tp& - operator*() const& + operator*() const& noexcept { return this->_M_get(); } constexpr _Tp& - operator*()& + operator*()& noexcept { return this->_M_get(); } constexpr _Tp&& - operator*()&& + operator*()&& noexcept { return std::move(this->_M_get()); } constexpr const _Tp&& - operator*() const&& + operator*() const&& noexcept { return std::move(this->_M_get()); } constexpr explicit operator bool() const noexcept diff --git a/libstdc++-v3/testsuite/20_util/optional/assignment/noexcept.cc b/libstdc++-v3/testsuite/20_util/optional/assignment/noexcept.cc new file mode 100644 index 00000000000..45592b2a18c --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/optional/assignment/noexcept.cc @@ -0,0 +1,81 @@ +// Copyright (C) 2020 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// . + +// { dg-do compile { target c++17 } } + +#include + +template +struct X +{ + X() noexcept(B); + + X(const X&) noexcept(B); + X& operator=(const X&) noexcept(B); + + X(int) noexcept(B); + X& operator=(int) noexcept(false); + + X(void*) noexcept(true); + X& operator=(void*) noexcept(B); + + X(const X&) noexcept(B); + X& operator=(const X&) noexcept(B); + + X(std::initializer_list, int) noexcept(B); +}; + +using std::is_nothrow_assignable_v; + +using Xyes = X; +using Xno = X; +using Oyes = std::optional; +using Ono = std::optional; + +static_assert( is_nothrow_assignable_v ); +static_assert( is_nothrow_assignable_v ); +static_assert( is_nothrow_assignable_v ); +static_assert( ! is_nothrow_assignable_v ); +static_assert( is_nothrow_assignable_v ); +static_assert( is_nothrow_assignable_v ); +static_assert( is_nothrow_assignable_v ); + +static_assert( is_nothrow_assignable_v ); +static_assert( ! is_nothrow_assignable_v ); +static_assert( ! is_nothrow_assignable_v ); +static_assert( ! is_nothrow_assignable_v ); +static_assert( ! is_nothrow_assignable_v ); +static_assert( ! is_nothrow_assignable_v ); +static_assert( ! is_nothrow_assignable_v ); + +Xyes xyes; +Xno xno; +Oyes oyes; +Ono ono; +static_assert( noexcept(oyes.emplace()) ); +static_assert( noexcept(oyes.emplace(xyes)) ); +static_assert( noexcept(oyes.emplace(1)) ); +static_assert( noexcept(oyes.emplace(nullptr)) ); +static_assert( noexcept(oyes.emplace(xno)) ); +static_assert( noexcept(oyes.emplace({1,2,3}, 1)) ); + +static_assert( ! noexcept(ono.emplace()) ); +static_assert( ! noexcept(ono.emplace(xno)) ); +static_assert( ! noexcept(ono.emplace(1)) ); +static_assert( noexcept(ono.emplace(nullptr)) ); +static_assert( ! noexcept(ono.emplace(xyes)) ); +static_assert( ! noexcept(ono.emplace({1,2,3}, 1)) ); diff --git a/libstdc++-v3/testsuite/20_util/optional/cons/noexcept.cc b/libstdc++-v3/testsuite/20_util/optional/cons/noexcept.cc new file mode 100644 index 00000000000..a529f5d39ad --- /dev/null +++ b/libstdc++-v3/testsuite/20_util/optional/cons/noexcept.cc @@ -0,0 +1,64 @@ +// Copyright (C) 2020 Free Software Foundation, Inc. +// +// This file is part of the GNU ISO C++ Library. This library is free +// software; you can redistribute it and/or modify it under the +// terms of the GNU General Public License as published by the +// Free Software Foundation; either version 3, or (at your option) +// any later version. + +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License along +// with this library; see the file COPYING3. If not see +// . + +// { dg-do compile { target c++17 } } + +#include + +template +struct X +{ + X() noexcept(B); + X(const X&) noexcept(B); + + X(int) noexcept(B); + X(std::initializer_list, int) noexcept(B); + + X(const X&) noexcept(B); + + X& operator=(const X&) noexcept(false); +}; + +using std::is_nothrow_constructible_v; +using std::in_place_t; + +using Xyes = X; +using Xno = X; +using Oyes = std::optional; +using Ono = std::optional; + +static_assert( is_nothrow_constructible_v ); +static_assert( is_nothrow_constructible_v ); +static_assert( is_nothrow_constructible_v ); +static_assert( is_nothrow_constructible_v ); +static_assert( is_nothrow_constructible_v ); +static_assert( is_nothrow_constructible_v, + long> ); +static_assert( is_nothrow_constructible_v ); +static_assert( is_nothrow_constructible_v ); + +static_assert( is_nothrow_constructible_v ); +static_assert( is_nothrow_constructible_v ); +static_assert( ! is_nothrow_constructible_v ); +static_assert( ! is_nothrow_constructible_v ); +static_assert( ! is_nothrow_constructible_v ); +static_assert( ! is_nothrow_constructible_v, + long> ); +static_assert( ! is_nothrow_constructible_v ); +static_assert( ! is_nothrow_constructible_v ); -- 2.30.2