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// <functional>10 11// struct is_placeholder12 13#include <functional>14#include <type_traits>15 16#include "test_macros.h"17 18template <int Expected, class T>19void20test(const T&)21{22 static_assert(std::is_placeholder<T>::value == Expected, "");23 LIBCPP_STATIC_ASSERT(std::is_placeholder<T&>::value == Expected, "");24 LIBCPP_STATIC_ASSERT(std::is_placeholder<const T>::value == Expected, "");25 LIBCPP_STATIC_ASSERT(std::is_placeholder<const T&>::value == Expected, "");26 static_assert(std::is_base_of<std::integral_constant<int, Expected>, std::is_placeholder<T> >::value, "");27 LIBCPP_STATIC_ASSERT(std::is_base_of<std::integral_constant<int, Expected>, std::is_placeholder<T&> >::value, "");28 LIBCPP_STATIC_ASSERT(std::is_base_of<std::integral_constant<int, Expected>, std::is_placeholder<const T> >::value, "");29 LIBCPP_STATIC_ASSERT(std::is_base_of<std::integral_constant<int, Expected>, std::is_placeholder<const T&> >::value, "");30 31#if TEST_STD_VER > 1432 ASSERT_SAME_TYPE(decltype(std::is_placeholder_v<T>), const int);33 static_assert(std::is_placeholder_v<T> == Expected, "");34 LIBCPP_STATIC_ASSERT(std::is_placeholder_v<T&> == Expected, "");35 LIBCPP_STATIC_ASSERT(std::is_placeholder_v<const T> == Expected, "");36 LIBCPP_STATIC_ASSERT(std::is_placeholder_v<const T&> == Expected, "");37#endif38}39 40struct C {};41 42int main(int, char**)43{44 test<1>(std::placeholders::_1);45 test<2>(std::placeholders::_2);46 test<3>(std::placeholders::_3);47 test<4>(std::placeholders::_4);48 test<5>(std::placeholders::_5);49 test<6>(std::placeholders::_6);50 test<7>(std::placeholders::_7);51 test<8>(std::placeholders::_8);52 test<9>(std::placeholders::_9);53 test<10>(std::placeholders::_10);54 test<0>(4);55 test<0>(5.5);56 test<0>('a');57 test<0>(C());58 59 return 0;60}61