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 // UNSUPPORTED: c++03, c++11, c++14
10 // UNSUPPORTED: libcpp-no-deduction-guides
11 
12 // <functional>
13 
14 // template <class T>
15 //   reference_wrapper(T&) -> reference_wrapper<T>;
16 
17 #include <functional>
18 
main()19 int main()
20 {
21     int i = 0;
22     std::reference_wrapper ri(i);
23     static_assert(std::is_same_v<decltype(ri), std::reference_wrapper<int>>);
24     std::reference_wrapper ri2(ri);
25     static_assert(std::is_same_v<decltype(ri2), std::reference_wrapper<int>>);
26     const int j = 0;
27     std::reference_wrapper rj(j);
28     static_assert(std::is_same_v<decltype(rj), std::reference_wrapper<const int>>);
29     std::reference_wrapper rj2(rj);
30     static_assert(std::is_same_v<decltype(rj2), std::reference_wrapper<const int>>);
31 }
32