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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 // <functional> 10 // 11 // template <class T> 12 // struct unwrap_reference; 13 // 14 // template <class T> 15 // using unwrap_reference_t = typename unwrap_reference<T>::type; 16 17 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17 18 19 #include <functional> 20 #include <type_traits> 21 22 #include "test_macros.h" 23 24 25 template <typename T, typename Expected> 26 void check_equal() { 27 static_assert(std::is_same_v<typename std::unwrap_reference<T>::type, Expected>); 28 static_assert(std::is_same_v<typename std::unwrap_reference<T>::type, std::unwrap_reference_t<T>>); 29 } 30 31 template <typename T> 32 void check() { 33 check_equal<T, T>(); 34 check_equal<T&, T&>(); 35 check_equal<T const, T const>(); 36 check_equal<T const&, T const&>(); 37 38 check_equal<std::reference_wrapper<T>, T&>(); 39 check_equal<std::reference_wrapper<T const>, T const&>(); 40 } 41 42 struct T { }; 43 44 int main(int, char**) { 45 check<T>(); 46 check<int>(); 47 check<float>(); 48 49 check<T*>(); 50 check<int*>(); 51 check<float*>(); 52 53 return 0; 54 } 55