llvm-project/libcxx/include/__compare/compare_partial_order_fallb...

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//===----------------------------------------------------------------------===//
//
// 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___COMPARE_COMPARE_PARTIAL_ORDER_FALLBACK
#define _LIBCPP___COMPARE_COMPARE_PARTIAL_ORDER_FALLBACK
#include <__compare/ordering.h>
#include <__compare/partial_order.h>
#include <__config>
#include <__utility/forward.h>
#include <__utility/priority_tag.h>
#include <type_traits>
#ifndef _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER > 17
// [cmp.alg]
namespace __compare_partial_order_fallback {
struct __fn {
template<class _Tp, class _Up>
requires is_same_v<decay_t<_Tp>, decay_t<_Up>>
_LIBCPP_HIDE_FROM_ABI static constexpr auto
__go(_Tp&& __t, _Up&& __u, __priority_tag<1>)
noexcept(noexcept(_VSTD::partial_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u))))
-> decltype( _VSTD::partial_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u)))
{ return _VSTD::partial_order(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u)); }
template<class _Tp, class _Up>
requires is_same_v<decay_t<_Tp>, decay_t<_Up>>
_LIBCPP_HIDE_FROM_ABI static constexpr auto
__go(_Tp&& __t, _Up&& __u, __priority_tag<0>)
noexcept(noexcept(_VSTD::forward<_Tp>(__t) == _VSTD::forward<_Up>(__u) ? partial_ordering::equivalent :
_VSTD::forward<_Tp>(__t) < _VSTD::forward<_Up>(__u) ? partial_ordering::less :
_VSTD::forward<_Up>(__u) < _VSTD::forward<_Tp>(__t) ? partial_ordering::greater :
partial_ordering::unordered))
-> decltype( _VSTD::forward<_Tp>(__t) == _VSTD::forward<_Up>(__u) ? partial_ordering::equivalent :
_VSTD::forward<_Tp>(__t) < _VSTD::forward<_Up>(__u) ? partial_ordering::less :
_VSTD::forward<_Up>(__u) < _VSTD::forward<_Tp>(__t) ? partial_ordering::greater :
partial_ordering::unordered)
{
return _VSTD::forward<_Tp>(__t) == _VSTD::forward<_Up>(__u) ? partial_ordering::equivalent :
_VSTD::forward<_Tp>(__t) < _VSTD::forward<_Up>(__u) ? partial_ordering::less :
_VSTD::forward<_Up>(__u) < _VSTD::forward<_Tp>(__t) ? partial_ordering::greater :
partial_ordering::unordered;
}
template<class _Tp, class _Up>
_LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Tp&& __t, _Up&& __u) const
noexcept(noexcept(__go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<1>())))
-> decltype( __go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<1>()))
{ return __go(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u), __priority_tag<1>()); }
};
} // namespace __compare_partial_order_fallback
inline namespace __cpo {
inline constexpr auto compare_partial_order_fallback = __compare_partial_order_fallback::__fn{};
} // namespace __cpo
#endif // _LIBCPP_STD_VER > 17
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___COMPARE_COMPARE_PARTIAL_ORDER_FALLBACK