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
11
12 // <functional>
13
14 // Hashing a struct w/o a defined hash should *not* fail, but it should
15 // create a type that is not constructible and not callable.
16 // See also: https://cplusplus.github.io/LWG/lwg-defects.html#2543
17
18 #include <functional>
19 #include <cassert>
20 #include <type_traits>
21
22 #include "test_macros.h"
23
24 struct X {};
25
main()26 int main()
27 {
28 using H = std::hash<X>;
29 static_assert(!std::is_default_constructible<H>::value, "");
30 static_assert(!std::is_copy_constructible<H>::value, "");
31 static_assert(!std::is_move_constructible<H>::value, "");
32 static_assert(!std::is_copy_assignable<H>::value, "");
33 static_assert(!std::is_move_assignable<H>::value, "");
34 #if TEST_STD_VER > 14
35 static_assert(!std::is_invocable<H, X&>::value, "");
36 static_assert(!std::is_invocable<H, X const&>::value, "");
37 #endif
38 }
39