1 //===----------------------------------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 // UNSUPPORTED: c++98, c++03, c++11, c++14
11 // <optional>
12
13 // A program that necessitates the instantiation of template optional for
14 // (possibly cv-qualified) nullopt_t is ill-formed.
15
16 #include <optional>
17
main()18 int main()
19 {
20 using std::optional;
21 using std::nullopt_t;
22 using std::nullopt;
23
24 optional<nullopt_t> opt; // expected-note 1 {{requested here}}
25 optional<const nullopt_t> opt1; // expected-note 1 {{requested here}}
26 optional<nullopt_t &> opt2; // expected-note 1 {{requested here}}
27 optional<nullopt_t &&> opt3; // expected-note 1 {{requested here}}
28 // expected-error@optional:* 4 {{instantiation of optional with nullopt_t is ill-formed}}
29 }
30