52 lines
2.0 KiB
C++
52 lines
2.0 KiB
C++
// Copyright (C) 2018-2020 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
|
|
// <http://www.gnu.org/licenses/>.
|
|
|
|
// { dg-options "-std=gnu++2a" }
|
|
// { dg-do compile { target c++2a } }
|
|
|
|
#include <type_traits>
|
|
|
|
template<typename T, typename U> struct expect_same;
|
|
template<typename T> struct expect_same<T, T> : std::true_type { };
|
|
|
|
template<typename T, typename U = std::decay_t<T>>
|
|
constexpr bool check()
|
|
{
|
|
using T2 = typename std::unwrap_ref_decay<T>::type;
|
|
static_assert(expect_same<T2, std::unwrap_ref_decay_t<T>>::value);
|
|
return expect_same<T2, U>::value;
|
|
}
|
|
|
|
void
|
|
test01()
|
|
{
|
|
static_assert( check<int>() );
|
|
static_assert( check<const int>() );
|
|
static_assert( check<const int&>() );
|
|
static_assert( check<const int*>() );
|
|
static_assert( check<const int*&>() );
|
|
|
|
// reference_wrapper types (including cv and references) get unwrapped:
|
|
static_assert( check<std::reference_wrapper<int>, int&>() );
|
|
static_assert( check<std::reference_wrapper<int>&, int&>() );
|
|
static_assert( check<const std::reference_wrapper<int>, int&>() );
|
|
static_assert( check<const std::reference_wrapper<int>&, int&>() );
|
|
static_assert( check<std::reference_wrapper<const int>, const int&>() );
|
|
static_assert( check<std::reference_wrapper<const int>&, const int&>() );
|
|
static_assert( check<std::reference_wrapper<long>, long&>() );
|
|
}
|