gcc/libstdc++-v3/include/experimental/array
Jonathan Wakely cb0de9b60c P0325R4 to_array from LFTS with updates
As an extension to what the standard requires, this also adds
conditional noexcept-specifiers to the std::to_array functions.

	P0325R4 to_array from LFTS with updates
	* include/experimental/array (to_array): Qualify call to __to_array.
	* include/std/array (__cpp_lib_to_array, to_array): Define for C++20.
	* include/std/version (__cpp_lib_to_array): Likewise.
	* testsuite/23_containers/array/creation/1.cc: New test.
	* testsuite/23_containers/array/creation/2.cc: New test.
	* testsuite/23_containers/array/creation/3_neg.cc: New test.
	* testsuite/23_containers/array/tuple_interface/tuple_element_neg.cc:
	Use zero for dg-error line number.

From-SVN: r274209
2019-08-08 11:18:53 +01:00

117 lines
3.3 KiB
C++

// <experimental/array> -*- C++ -*-
// Copyright (C) 2015-2019 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.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file experimental/array
* This is a TS C++ Library header.
* @ingroup libfund-ts
*/
#ifndef _GLIBCXX_EXPERIMENTAL_ARRAY
#define _GLIBCXX_EXPERIMENTAL_ARRAY 1
#pragma GCC system_header
#if __cplusplus >= 201402L
#include <array>
#include <experimental/type_traits>
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
namespace experimental
{
inline namespace fundamentals_v2
{
#define __cpp_lib_experimental_make_array 201505
/**
* @defgroup make_array Array creation functions
* @ingroup libfund-ts
*
* Array creation functions as described in N4529,
* Working Draft, C++ Extensions for Library Fundamentals, Version 2
*
* @{
*/
template<typename _Dest, typename... _Types>
struct __make_array_elem
{
using type = _Dest;
};
template<typename... _Types>
struct __make_array_elem<void, _Types...>
: common_type<_Types...>
{
template <typename>
struct __is_reference_wrapper : false_type
{};
template <typename _Up>
struct __is_reference_wrapper<reference_wrapper<_Up>> : true_type
{};
static_assert(!__or_<__is_reference_wrapper<decay_t<_Types>>...>::value,
"make_array must be used with an explicit target type when"
"any of the arguments is a reference_wrapper");
};
/// Create a std::array from a variable-length list of arguments.
template <typename _Dest = void, typename... _Types>
constexpr
array<typename __make_array_elem<_Dest, _Types...>::type, sizeof...(_Types)>
make_array(_Types&&... __t)
{
return {{ std::forward<_Types>(__t)... }};
}
template <typename _Tp, size_t _Nm, size_t... _Idx>
constexpr array<remove_cv_t<_Tp>, _Nm>
__to_array(_Tp (&__a)[_Nm], index_sequence<_Idx...>)
{
return {{__a[_Idx]...}};
}
/// Create a std::array from an array.
template <typename _Tp, size_t _Nm>
constexpr array<remove_cv_t<_Tp>, _Nm>
to_array(_Tp (&__a)[_Nm])
noexcept(is_nothrow_constructible<remove_cv_t<_Tp>, _Tp&>::value)
{
return experimental::__to_array(__a, make_index_sequence<_Nm>{});
}
// @} group make_array
} // namespace fundamentals_v2
} // namespace experimental
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#endif // C++14
#endif // _GLIBCXX_EXPERIMENTAL_ARRAY