| // Copyright (C) 2019-2021 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 |
| // <http://www.gnu.org/licenses/>. |
| |
| // { dg-options "-std=gnu++2a" } |
| // { dg-do compile { target c++2a } } |
| |
| #include <iterator> |
| |
| template<typename T> |
| using PI = std::projected<T, std::identity>; |
| |
| static_assert(std::same_as<PI<int*>::value_type, int>); |
| static_assert(std::same_as<decltype(*std::declval<const PI<int*>&>()), int&>); |
| |
| struct X |
| { |
| using value_type = char*; |
| char* const& operator*() const; |
| }; |
| static_assert( std::indirectly_readable<X> ); |
| static_assert( std::indirectly_readable<X&> ); |
| static_assert( std::indirectly_readable<const X> ); |
| static_assert(std::same_as<PI<X>::value_type, char*>); |
| static_assert(std::same_as<decltype(*std::declval<PI<X>&>()), char* const&>); |
| |
| struct Y; |
| using PY = std::projected<const Y*, int Y::*>; |
| static_assert(std::same_as<PY::value_type, int>); |
| static_assert(std::same_as<decltype(*std::declval<PY&>()), const int&>); |
