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// <optional>
11
12// template <class T>
13// class optional
14// {
15// public:
16// typedef T value_type;
17// ...
18
19#include <optional>
20#include <type_traits>
21
22#include "test_macros.h"
23
24using std::optional;
25
26template <class Opt, class T>
27void
28test()
29{
30 static_assert(std::is_same<typename Opt::value_type, T>::value, "");
31}
32
33int main(int, char**)
34{
35 test<optional<int>, int>();
36 test<optional<const int>, const int>();
37 test<optional<double>, double>();
38 test<optional<const double>, const double>();
39
40 return 0;
41}
42

source code of libcxx/test/std/utilities/optional/optional.object/types.pass.cpp