61 lines · cpp
1//===----------------------------------------------------------------------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9// UNSUPPORTED: c++03, c++1110#include <functional>11#include <string>12 13#include "test_macros.h"14 15template <class T>16struct is_transparent17{18private:19 struct two {char lx; char lxx;};20 template <class U> static two test(...);21 template <class U> static char test(typename U::is_transparent* = 0);22public:23 static const bool value = sizeof(test<T>(0)) == 1;24};25 26 27int main(int, char**)28{29 static_assert ( !is_transparent<std::less<int>>::value, "" );30 static_assert ( !is_transparent<std::less<std::string>>::value, "" );31 static_assert ( is_transparent<std::less<void>>::value, "" );32 static_assert ( is_transparent<std::less<>>::value, "" );33 34 static_assert ( !is_transparent<std::less_equal<int>>::value, "" );35 static_assert ( !is_transparent<std::less_equal<std::string>>::value, "" );36 static_assert ( is_transparent<std::less_equal<void>>::value, "" );37 static_assert ( is_transparent<std::less_equal<>>::value, "" );38 39 static_assert ( !is_transparent<std::equal_to<int>>::value, "" );40 static_assert ( !is_transparent<std::equal_to<std::string>>::value, "" );41 static_assert ( is_transparent<std::equal_to<void>>::value, "" );42 static_assert ( is_transparent<std::equal_to<>>::value, "" );43 44 static_assert ( !is_transparent<std::not_equal_to<int>>::value, "" );45 static_assert ( !is_transparent<std::not_equal_to<std::string>>::value, "" );46 static_assert ( is_transparent<std::not_equal_to<void>>::value, "" );47 static_assert ( is_transparent<std::not_equal_to<>>::value, "" );48 49 static_assert ( !is_transparent<std::greater<int>>::value, "" );50 static_assert ( !is_transparent<std::greater<std::string>>::value, "" );51 static_assert ( is_transparent<std::greater<void>>::value, "" );52 static_assert ( is_transparent<std::greater<>>::value, "" );53 54 static_assert ( !is_transparent<std::greater_equal<int>>::value, "" );55 static_assert ( !is_transparent<std::greater_equal<std::string>>::value, "" );56 static_assert ( is_transparent<std::greater_equal<void>>::value, "" );57 static_assert ( is_transparent<std::greater_equal<>>::value, "" );58 59 return 0;60}61