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
10 // <experimental/type_traits>
11
12 #include <experimental/type_traits>
13 #include <string>
14
15 #include "test_macros.h"
16
17 namespace ex = std::experimental;
18
19 template <typename T>
20 using callFoo = decltype(std::declval<T&>().Foo());
21
22 struct yesFoo {
FooyesFoo23 int Foo() { return 0; }
24 };
25
26 struct noFoo {
27 };
28
29 struct wrongFoo {
FoowrongFoo30 std::string Foo() { return ""; }
31 };
32
33 struct convertibleFoo {
FooconvertibleFoo34 long Foo() { return 0; }
35 };
36
37
38 template <typename T, typename Res>
test()39 void test() {
40 static_assert( std::is_same<Res, typename ex::detected_t<callFoo, T>>::value, "" );
41 }
42
main(int,char **)43 int main(int, char**) {
44 test<yesFoo, int>();
45 test<noFoo, ex::nonesuch>(); // lookup failure returns nonesuch
46 test<wrongFoo, std::string>();
47
48 return 0;
49 }
50