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 // common_type
13 
14 #include <type_traits>
15 
16 int main()
17 {
18     static_assert((std::is_same<std::common_type<int>::type, int>::value), "");
19     static_assert((std::is_same<std::common_type<char>::type, char>::value), "");
20 #if _LIBCPP_STD_VER > 11
21     static_assert((std::is_same<std::common_type_t<int>,   int>::value), "");
22     static_assert((std::is_same<std::common_type_t<char>, char>::value), "");
23 #endif
24 
25     static_assert((std::is_same<std::common_type<               int>::type, int>::value), "");
26     static_assert((std::is_same<std::common_type<const          int>::type, int>::value), "");
27     static_assert((std::is_same<std::common_type<      volatile int>::type, int>::value), "");
28     static_assert((std::is_same<std::common_type<const volatile int>::type, int>::value), "");
29 
30     static_assert((std::is_same<std::common_type<int,           int>::type, int>::value), "");
31     static_assert((std::is_same<std::common_type<int,     const int>::type, int>::value), "");
32 
33     static_assert((std::is_same<std::common_type<long,       const int>::type, long>::value), "");
34     static_assert((std::is_same<std::common_type<const long,       int>::type, long>::value), "");
35     static_assert((std::is_same<std::common_type<long,    volatile int>::type, long>::value), "");
36     static_assert((std::is_same<std::common_type<volatile long,    int>::type, long>::value), "");
37     static_assert((std::is_same<std::common_type<const long, const int>::type, long>::value), "");
38 
39     static_assert((std::is_same<std::common_type<double, char>::type, double>::value), "");
40     static_assert((std::is_same<std::common_type<short, char>::type, int>::value), "");
41 #if _LIBCPP_STD_VER > 11
42     static_assert((std::is_same<std::common_type_t<double, char>, double>::value), "");
43     static_assert((std::is_same<std::common_type_t<short, char>, int>::value), "");
44 #endif
45 
46     static_assert((std::is_same<std::common_type<double, char, long long>::type, double>::value), "");
47     static_assert((std::is_same<std::common_type<unsigned, char, long long>::type, long long>::value), "");
48 #if _LIBCPP_STD_VER > 11
49     static_assert((std::is_same<std::common_type_t<double, char, long long>, double>::value), "");
50     static_assert((std::is_same<std::common_type_t<unsigned, char, long long>, long long>::value), "");
51 #endif
52 }
53