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1// -*- C++ -*-2//===----------------------------------------------------------------------===//3//4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.5// See https://llvm.org/LICENSE.txt for license information.6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception7//8//===----------------------------------------------------------------------===//9 10#ifndef _LIBCPP___FUNCTIONAL_IS_TRANSPARENT11#define _LIBCPP___FUNCTIONAL_IS_TRANSPARENT12 13#include <__config>14#include <__type_traits/void_t.h>15 16#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)17# pragma GCC system_header18#endif19 20_LIBCPP_BEGIN_NAMESPACE_STD21 22#if _LIBCPP_STD_VER >= 1423 24template <class _Tp, class _Key = void, class = void>25inline const bool __is_transparent_v = false;26 27template <class _Tp, class _Key>28inline const bool __is_transparent_v<_Tp, _Key, __void_t<typename _Tp::is_transparent> > = true;29 30#endif31 32// Two types are considered transparently comparable if `comparator(key, arg)` is equivalent to `comparator(key,33// <implicit cast to KeyT>(arg))`.34//35// This is different from `__is_transparent_v`, which is only a property of the comparator and doesn't provide36// additional semantic guarantees.37template <class _Comparator, class _KeyT, class _Arg, class = void>38inline const bool __is_transparently_comparable_v = false;39 40_LIBCPP_END_NAMESPACE_STD41 42#endif // _LIBCPP___FUNCTIONAL_IS_TRANSPARENT43