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 // type_traits
10
11 // is_function
12
13 #include <type_traits>
14 #include <cstddef> // for std::nullptr_t
15
16 #include "test_macros.h"
17
18 // NOTE: On Windows the function `test_is_function<void()>` and
19 // `test_is_function<void() noexcept> has the same mangled despite being
20 // a distinct instantiation. This causes Clang to emit an error. However
21 // structs do not have this problem.
22
23 template <class T>
24 struct test_is_function {
25 static_assert( std::is_function<T>::value, "");
26 static_assert( std::is_function<const T>::value, "");
27 static_assert( std::is_function<volatile T>::value, "");
28 static_assert( std::is_function<const volatile T>::value, "");
29 #if TEST_STD_VER > 14
30 static_assert( std::is_function_v<T>, "");
31 static_assert( std::is_function_v<const T>, "");
32 static_assert( std::is_function_v<volatile T>, "");
33 static_assert( std::is_function_v<const volatile T>, "");
34 #endif
35 };
36
37 template <class T>
38 struct test_is_not_function {
39 static_assert(!std::is_function<T>::value, "");
40 static_assert(!std::is_function<const T>::value, "");
41 static_assert(!std::is_function<volatile T>::value, "");
42 static_assert(!std::is_function<const volatile T>::value, "");
43 #if TEST_STD_VER > 14
44 static_assert(!std::is_function_v<T>, "");
45 static_assert(!std::is_function_v<const T>, "");
46 static_assert(!std::is_function_v<volatile T>, "");
47 static_assert(!std::is_function_v<const volatile T>, "");
48 #endif
49 };
50
51 class Empty
52 {
53 };
54
55 class NotEmpty
56 {
57 virtual ~NotEmpty();
58 };
59
60 union Union {};
61
62 struct bit_zero
63 {
64 int : 0;
65 };
66
67 class Abstract
68 {
69 virtual ~Abstract() = 0;
70 };
71
72 enum Enum {zero, one};
73 struct incomplete_type;
74
75 typedef void (*FunctionPtr)();
76
main(int,char **)77 int main(int, char**)
78 {
79 test_is_function<void(void)>();
80 test_is_function<int(int)>();
81 test_is_function<int(int, double)>();
82 test_is_function<int(Abstract *)>();
83 test_is_function<void(...)>();
84
85 test_is_not_function<std::nullptr_t>();
86 test_is_not_function<void>();
87 test_is_not_function<int>();
88 test_is_not_function<int&>();
89 test_is_not_function<int&&>();
90 test_is_not_function<int*>();
91 test_is_not_function<double>();
92 test_is_not_function<char[3]>();
93 test_is_not_function<char[]>();
94 test_is_not_function<Union>();
95 test_is_not_function<Enum>();
96 test_is_not_function<FunctionPtr>(); // function pointer is not a function
97 test_is_not_function<Empty>();
98 test_is_not_function<bit_zero>();
99 test_is_not_function<NotEmpty>();
100 test_is_not_function<Abstract>();
101 test_is_not_function<Abstract*>();
102 test_is_not_function<incomplete_type>();
103
104 #if TEST_STD_VER >= 11
105 test_is_function<void() noexcept>();
106 test_is_function<void() const && noexcept>();
107 #endif
108
109 return 0;
110 }
111