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// add_pointer
12// If T names a referenceable type or a (possibly cv-qualified) void type then
13// the member typedef type shall name the same type as remove_reference_t<T>*;
14// otherwise, type shall name T.
15
16#include <type_traits>
17#include "test_macros.h"
18
19template <class T, class U>
20void test_add_pointer()
21{
22 ASSERT_SAME_TYPE(U, typename std::add_pointer<T>::type);
23#if TEST_STD_VER > 11
24 ASSERT_SAME_TYPE(U, std::add_pointer_t<T>);
25#endif
26}
27
28template <class F>
29void test_function0()
30{
31 ASSERT_SAME_TYPE(F*, typename std::add_pointer<F>::type);
32#if TEST_STD_VER > 11
33 ASSERT_SAME_TYPE(F*, std::add_pointer_t<F>);
34#endif
35}
36
37template <class F>
38void test_function1()
39{
40 ASSERT_SAME_TYPE(F, typename std::add_pointer<F>::type);
41#if TEST_STD_VER > 11
42 ASSERT_SAME_TYPE(F, std::add_pointer_t<F>);
43#endif
44}
45
46struct Foo {};
47
48int main(int, char**)
49{
50 test_add_pointer<void, void*>();
51 test_add_pointer<int, int*>();
52 test_add_pointer<int[3], int(*)[3]>();
53 test_add_pointer<int&, int*>();
54 test_add_pointer<const int&, const int*>();
55 test_add_pointer<int*, int**>();
56 test_add_pointer<const int*, const int**>();
57 test_add_pointer<Foo, Foo*>();
58
59// LWG 2101 specifically talks about add_pointer and functions.
60// The term of art is "a referenceable type", which a cv- or ref-qualified function is not.
61 test_function0<void()>();
62#if TEST_STD_VER >= 11
63 test_function1<void() const>();
64 test_function1<void() &>();
65 test_function1<void() &&>();
66 test_function1<void() const &>();
67 test_function1<void() const &&>();
68#endif
69
70// But a cv- or ref-qualified member function *is* "a referenceable type"
71 test_function0<void (Foo::*)()>();
72#if TEST_STD_VER >= 11
73 test_function0<void (Foo::*)() const>();
74 test_function0<void (Foo::*)() &>();
75 test_function0<void (Foo::*)() &&>();
76 test_function0<void (Foo::*)() const &>();
77 test_function0<void (Foo::*)() const &&>();
78#endif
79
80 return 0;
81}
82

source code of libcxx/test/std/utilities/meta/meta.trans/meta.trans.ptr/add_pointer.pass.cpp