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 // is_function
13
14 #include <type_traits>
15 #include <cstddef> // for std::nullptr_t
16
17 #include "test_macros.h"
18
19 // NOTE: On Windows the function `test_is_function<void()>` and
20 // `test_is_function<void() noexcept> has the same mangled despite being
21 // a distinct instantiation. This causes Clang to emit an error. However
22 // structs do not have this problem.
23
24 template <class T>
25 struct test_is_function {
26 static_assert( std::is_function<T>::value, "");
27 static_assert( std::is_function<const T>::value, "");
28 static_assert( std::is_function<volatile T>::value, "");
29 static_assert( std::is_function<const volatile T>::value, "");
30 #if TEST_STD_VER > 14
31 static_assert( std::is_function_v<T>, "");
32 static_assert( std::is_function_v<const T>, "");
33 static_assert( std::is_function_v<volatile T>, "");
34 static_assert( std::is_function_v<const volatile T>, "");
35 #endif
36 };
37
38 template <class T>
39 struct test_is_not_function {
40 static_assert(!std::is_function<T>::value, "");
41 static_assert(!std::is_function<const T>::value, "");
42 static_assert(!std::is_function<volatile T>::value, "");
43 static_assert(!std::is_function<const volatile T>::value, "");
44 #if TEST_STD_VER > 14
45 static_assert(!std::is_function_v<T>, "");
46 static_assert(!std::is_function_v<const T>, "");
47 static_assert(!std::is_function_v<volatile T>, "");
48 static_assert(!std::is_function_v<const volatile T>, "");
49 #endif
50 };
51
52 class Empty
53 {
54 };
55
56 class NotEmpty
57 {
58 virtual ~NotEmpty();
59 };
60
61 union Union {};
62
63 struct bit_zero
64 {
65 int : 0;
66 };
67
68 class Abstract
69 {
70 virtual ~Abstract() = 0;
71 };
72
73 enum Enum {zero, one};
74 struct incomplete_type;
75
76 typedef void (*FunctionPtr)();
77
main()78 int main()
79 {
80 test_is_function<void(void)>();
81 test_is_function<int(int)>();
82 test_is_function<int(int, double)>();
83 test_is_function<int(Abstract *)>();
84 test_is_function<void(...)>();
85
86 test_is_not_function<std::nullptr_t>();
87 test_is_not_function<void>();
88 test_is_not_function<int>();
89 test_is_not_function<int&>();
90 test_is_not_function<int&&>();
91 test_is_not_function<int*>();
92 test_is_not_function<double>();
93 test_is_not_function<char[3]>();
94 test_is_not_function<char[]>();
95 test_is_not_function<Union>();
96 test_is_not_function<Enum>();
97 test_is_not_function<FunctionPtr>(); // function pointer is not a function
98 test_is_not_function<Empty>();
99 test_is_not_function<bit_zero>();
100 test_is_not_function<NotEmpty>();
101 test_is_not_function<Abstract>();
102 test_is_not_function<Abstract*>();
103 test_is_not_function<incomplete_type>();
104
105 #if TEST_STD_VER >= 11
106 test_is_function<void() noexcept>();
107 test_is_function<void() const && noexcept>();
108 #endif
109 }
110