libcxx/include/__fwd/pair.h

//===---------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===---------------------------------------------------------------------===//

#ifndef _LIBCPP___FWD_PAIR_H
#define _LIBCPP___FWD_PAIR_H

#include <__config>
#include <__cstddef/size_t.h>
#include <__fwd/tuple.h>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

_LIBCPP_BEGIN_NAMESPACE_STD

template <class, class>
struct pair;

template <class _Type>
inline const bool __is_pair_v = false;

template <class _Type1, class _Type2>
inline const bool __is_pair_v<pair<_Type1, _Type2> > = true;

template <size_t _Ip, class _T1, class _T2>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 typename tuple_element<_Ip, pair<_T1, _T2> >::type&
get(pair<_T1, _T2>&) _NOEXCEPT;

template <size_t _Ip, class _T1, class _T2>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const typename tuple_element<_Ip, pair<_T1, _T2> >::type&
get(const pair<_T1, _T2>&) _NOEXCEPT;

#ifndef _LIBCPP_CXX03_LANG
template <size_t _Ip, class _T1, class _T2>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
get(pair<_T1, _T2>&&) _NOEXCEPT;

template <size_t _Ip, class _T1, class _T2>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
get(const pair<_T1, _T2>&&) _NOEXCEPT;
#endif

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP___FWD_PAIR_H