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 #include "test_macros.h" 17 18 struct E {}; 19 20 template <class T> 21 struct X { explicit X(T const&){} }; 22 23 template <class T> 24 struct S { explicit S(T const&){} }; 25 26 namespace std 27 { 28 template <typename T> 29 struct common_type<T, ::S<T> > 30 { 31 typedef S<T> type; 32 }; 33 } 34 35 #if TEST_STD_VER >= 11 36 template <class T, class U, class = void> 37 struct no_common_type : std::true_type {}; 38 39 template <class T, class U> 40 struct no_common_type<T, U, typename std::conditional<false, 41 typename std::common_type<T, U>::type, void>::type> : std::false_type {}; 42 #endif // TEST_STD_VER >= 11 43 44 int main() 45 { 46 static_assert((std::is_same<std::common_type<int>::type, int>::value), ""); 47 static_assert((std::is_same<std::common_type<char>::type, char>::value), ""); 48 #if TEST_STD_VER > 11 49 static_assert((std::is_same<std::common_type_t<int>, int>::value), ""); 50 static_assert((std::is_same<std::common_type_t<char>, char>::value), ""); 51 #endif 52 53 static_assert((std::is_same<std::common_type< int>::type, int>::value), ""); 54 static_assert((std::is_same<std::common_type<const int>::type, int>::value), ""); 55 static_assert((std::is_same<std::common_type< volatile int>::type, int>::value), ""); 56 static_assert((std::is_same<std::common_type<const volatile int>::type, int>::value), ""); 57 58 static_assert((std::is_same<std::common_type<int, int>::type, int>::value), ""); 59 static_assert((std::is_same<std::common_type<int, const int>::type, int>::value), ""); 60 61 static_assert((std::is_same<std::common_type<long, const int>::type, long>::value), ""); 62 static_assert((std::is_same<std::common_type<const long, int>::type, long>::value), ""); 63 static_assert((std::is_same<std::common_type<long, volatile int>::type, long>::value), ""); 64 static_assert((std::is_same<std::common_type<volatile long, int>::type, long>::value), ""); 65 static_assert((std::is_same<std::common_type<const long, const int>::type, long>::value), ""); 66 67 static_assert((std::is_same<std::common_type<double, char>::type, double>::value), ""); 68 static_assert((std::is_same<std::common_type<short, char>::type, int>::value), ""); 69 #if TEST_STD_VER > 11 70 static_assert((std::is_same<std::common_type_t<double, char>, double>::value), ""); 71 static_assert((std::is_same<std::common_type_t<short, char>, int>::value), ""); 72 #endif 73 74 static_assert((std::is_same<std::common_type<double, char, long long>::type, double>::value), ""); 75 static_assert((std::is_same<std::common_type<unsigned, char, long long>::type, long long>::value), ""); 76 #if TEST_STD_VER > 11 77 static_assert((std::is_same<std::common_type_t<double, char, long long>, double>::value), ""); 78 static_assert((std::is_same<std::common_type_t<unsigned, char, long long>, long long>::value), ""); 79 #endif 80 81 static_assert((std::is_same<std::common_type< void>::type, void>::value), ""); 82 static_assert((std::is_same<std::common_type<const void>::type, void>::value), ""); 83 static_assert((std::is_same<std::common_type< volatile void>::type, void>::value), ""); 84 static_assert((std::is_same<std::common_type<const volatile void>::type, void>::value), ""); 85 86 static_assert((std::is_same<std::common_type<void, const void>::type, void>::value), ""); 87 static_assert((std::is_same<std::common_type<const void, void>::type, void>::value), ""); 88 static_assert((std::is_same<std::common_type<void, volatile void>::type, void>::value), ""); 89 static_assert((std::is_same<std::common_type<volatile void, void>::type, void>::value), ""); 90 static_assert((std::is_same<std::common_type<const void, const void>::type, void>::value), ""); 91 92 #if TEST_STD_VER >= 11 93 static_assert((no_common_type<void, int>::value), ""); 94 static_assert((no_common_type<int, void>::value), ""); 95 static_assert((no_common_type<int, E>::value), ""); 96 static_assert((no_common_type<int, X<int> >::value), ""); 97 #endif // TEST_STD_VER >= 11 98 99 static_assert((std::is_same<std::common_type<int, S<int> >::type, S<int> >::value), ""); 100 static_assert((std::is_same<std::common_type<int, S<int>, S<int> >::type, S<int> >::value), ""); 101 static_assert((std::is_same<std::common_type<int, int, S<int> >::type, S<int> >::value), ""); 102 } 103
