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++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>
check_equal()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>
check()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
main(int,char **)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