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 // constexpr optional(in_place_t);
13 
14 // Test that the SFINAE "is_constructible<value_type>" isn't evaluated by the
15 // in_place_t constructor with no arguments when the Clang is trying to check
16 // copy constructor.
17 
18 #include <optional>
19 #include <type_traits>
20 #include <cassert>
21 
22 #include "test_macros.h"
23 #include "archetypes.h"
24 
25 using std::optional;
26 
27 struct Wrapped {
28   struct Inner {
29     bool Dummy = true;
30   };
31   std::optional<Inner> inner;
32 };
33 
main(int,char **)34 int main(int, char**) {
35   static_assert(std::is_default_constructible<Wrapped::Inner>::value, "");
36   Wrapped w;
37   w.inner.emplace();
38   assert(w.inner.has_value());
39 
40   return 0;
41 }
42