void_t.pass.cpp revision 06086258d3d8c48a916ec51c33e1ad8f46821b81 
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// type_traits
11
12// void_t
13
14#include <type_traits>
15
16#if _LIBCPP_STD_VER <= 14
17int main () {}
18#else
19
20template <class T>
21void test1()
22{
23    static_assert( std::is_same<void, std::void_t<T>>::value, "");
24    static_assert( std::is_same<void, std::void_t<const T>>::value, "");
25    static_assert( std::is_same<void, std::void_t<volatile T>>::value, "");
26    static_assert( std::is_same<void, std::void_t<const volatile T>>::value, "");
27}
28
29template <class T, class U>
30void test2()
31{
32    static_assert( std::is_same<void, std::void_t<T, U>>::value, "");
33    static_assert( std::is_same<void, std::void_t<const T, U>>::value, "");
34    static_assert( std::is_same<void, std::void_t<volatile T, U>>::value, "");
35    static_assert( std::is_same<void, std::void_t<const volatile T, U>>::value, "");
36
37    static_assert( std::is_same<void, std::void_t<T, const U>>::value, "");
38    static_assert( std::is_same<void, std::void_t<const T, const U>>::value, "");
39    static_assert( std::is_same<void, std::void_t<volatile T, const U>>::value, "");
40    static_assert( std::is_same<void, std::void_t<const volatile T, const U>>::value, "");
41}
42
43class Class
44{
45public:
46    ~Class();
47};
48
49int main()
50{
51    static_assert( std::is_same<void, std::void_t<>>::value, "");
52
53	test1<void>();
54	test1<int>();
55	test1<double>();
56	test1<int&>();
57	test1<Class>();
58	test1<Class[]>();
59	test1<Class[5]>();
60
61	test2<void, int>();
62	test2<double, int>();
63	test2<int&, int>();
64	test2<Class&, bool>();
65	test2<void *, int&>();
66
67    static_assert( std::is_same<void, std::void_t<int, double const &, Class, volatile int[], void>>::value, "");
68}
69#endif
70