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 | // UNSUPPORTED: c++03, c++11, c++14, c++17 |
10 | |
11 | // <iterator> |
12 | // |
13 | // reverse_iterator |
14 | // |
15 | // template<indirectly_swappable<Iterator> Iterator2> |
16 | // friend constexpr void |
17 | // iter_swap(const reverse_iterator& x, |
18 | // const reverse_iterator<Iterator2>& y) noexcept(see below); |
19 | |
20 | #include <iterator> |
21 | |
22 | #include <cassert> |
23 | #include <type_traits> |
24 | #include <utility> |
25 | #include "test_iterators.h" |
26 | #include "test_macros.h" |
27 | |
28 | constexpr bool test() { |
29 | // Can use `iter_swap` with a regular array. |
30 | { |
31 | constexpr int N = 3; |
32 | int a[N] = {0, 1, 2}; |
33 | |
34 | std::reverse_iterator<int*> rb(a + N); |
35 | std::reverse_iterator<int*> re(a + 1); |
36 | assert(a[0] == 0); |
37 | assert(a[2] == 2); |
38 | |
39 | static_assert(std::same_as<decltype(iter_swap(rb, re)), void>); |
40 | iter_swap(a: rb, b: re); |
41 | assert(a[0] == 2); |
42 | assert(a[2] == 0); |
43 | } |
44 | |
45 | // Check that the `iter_swap` customization point is being used. |
46 | { |
47 | int iter_swap_invocations = 0; |
48 | int a[] = {0, 1, 2}; |
49 | adl::Iterator base1 = adl::Iterator::TrackSwaps(a + 1, iter_swap_invocations); |
50 | adl::Iterator base2 = adl::Iterator::TrackSwaps(a + 2, iter_swap_invocations); |
51 | std::reverse_iterator<adl::Iterator> ri1(base1), ri2(base2); |
52 | iter_swap(ri1, ri2); |
53 | assert(iter_swap_invocations == 1); |
54 | |
55 | iter_swap(ri2, ri1); |
56 | assert(iter_swap_invocations == 2); |
57 | } |
58 | |
59 | // Check the `noexcept` specification. |
60 | { |
61 | { |
62 | struct ThrowingCopyNoexceptDecrement { |
63 | using value_type = int; |
64 | using difference_type = std::ptrdiff_t; |
65 | |
66 | ThrowingCopyNoexceptDecrement(); |
67 | ThrowingCopyNoexceptDecrement(const ThrowingCopyNoexceptDecrement&); |
68 | |
69 | int& operator*() const noexcept { static int x; return x; } |
70 | |
71 | ThrowingCopyNoexceptDecrement& operator++(); |
72 | ThrowingCopyNoexceptDecrement operator++(int); |
73 | ThrowingCopyNoexceptDecrement& operator--() noexcept; |
74 | ThrowingCopyNoexceptDecrement operator--(int) noexcept; |
75 | |
76 | bool operator==(const ThrowingCopyNoexceptDecrement&) const = default; |
77 | }; |
78 | static_assert(std::bidirectional_iterator<ThrowingCopyNoexceptDecrement>); |
79 | |
80 | static_assert(!std::is_nothrow_copy_constructible_v<ThrowingCopyNoexceptDecrement>); |
81 | static_assert( std::is_nothrow_copy_constructible_v<int*>); |
82 | ASSERT_NOEXCEPT(std::ranges::iter_swap(--std::declval<ThrowingCopyNoexceptDecrement&>(), --std::declval<int*&>())); |
83 | using RI1 = std::reverse_iterator<ThrowingCopyNoexceptDecrement>; |
84 | using RI2 = std::reverse_iterator<int*>; |
85 | ASSERT_NOT_NOEXCEPT(iter_swap(a: std::declval<RI1>(), b: std::declval<RI2>())); |
86 | ASSERT_NOT_NOEXCEPT(iter_swap(a: std::declval<RI2>(), b: std::declval<RI1>())); |
87 | } |
88 | |
89 | { |
90 | struct NoexceptCopyThrowingDecrement { |
91 | using value_type = int; |
92 | using difference_type = std::ptrdiff_t; |
93 | |
94 | NoexceptCopyThrowingDecrement(); |
95 | NoexceptCopyThrowingDecrement(const NoexceptCopyThrowingDecrement&) noexcept; |
96 | |
97 | int& operator*() const { static int x; return x; } |
98 | |
99 | NoexceptCopyThrowingDecrement& operator++(); |
100 | NoexceptCopyThrowingDecrement operator++(int); |
101 | NoexceptCopyThrowingDecrement& operator--(); |
102 | NoexceptCopyThrowingDecrement operator--(int); |
103 | |
104 | bool operator==(const NoexceptCopyThrowingDecrement&) const = default; |
105 | }; |
106 | static_assert(std::bidirectional_iterator<NoexceptCopyThrowingDecrement>); |
107 | |
108 | static_assert( std::is_nothrow_copy_constructible_v<NoexceptCopyThrowingDecrement>); |
109 | static_assert( std::is_nothrow_copy_constructible_v<int*>); |
110 | ASSERT_NOT_NOEXCEPT(std::ranges::iter_swap(--std::declval<NoexceptCopyThrowingDecrement&>(), --std::declval<int*&>())); |
111 | using RI1 = std::reverse_iterator<NoexceptCopyThrowingDecrement>; |
112 | using RI2 = std::reverse_iterator<int*>; |
113 | ASSERT_NOT_NOEXCEPT(iter_swap(a: std::declval<RI1>(), b: std::declval<RI2>())); |
114 | ASSERT_NOT_NOEXCEPT(iter_swap(a: std::declval<RI2>(), b: std::declval<RI1>())); |
115 | } |
116 | |
117 | { |
118 | struct NoexceptCopyAndDecrement { |
119 | using value_type = int; |
120 | using difference_type = std::ptrdiff_t; |
121 | |
122 | NoexceptCopyAndDecrement(); |
123 | NoexceptCopyAndDecrement(const NoexceptCopyAndDecrement&) noexcept; |
124 | |
125 | int& operator*() const noexcept { static int x; return x; } |
126 | |
127 | NoexceptCopyAndDecrement& operator++(); |
128 | NoexceptCopyAndDecrement operator++(int); |
129 | NoexceptCopyAndDecrement& operator--() noexcept; |
130 | NoexceptCopyAndDecrement operator--(int) noexcept; |
131 | |
132 | bool operator==(const NoexceptCopyAndDecrement&) const = default; |
133 | }; |
134 | static_assert(std::bidirectional_iterator<NoexceptCopyAndDecrement>); |
135 | |
136 | static_assert( std::is_nothrow_copy_constructible_v<NoexceptCopyAndDecrement>); |
137 | static_assert( std::is_nothrow_copy_constructible_v<int*>); |
138 | ASSERT_NOEXCEPT(std::ranges::iter_swap(--std::declval<NoexceptCopyAndDecrement&>(), --std::declval<int*&>())); |
139 | using RI1 = std::reverse_iterator<NoexceptCopyAndDecrement>; |
140 | using RI2 = std::reverse_iterator<int*>; |
141 | ASSERT_NOEXCEPT(iter_swap(a: std::declval<RI1>(), b: std::declval<RI2>())); |
142 | ASSERT_NOEXCEPT(iter_swap(a: std::declval<RI2>(), b: std::declval<RI1>())); |
143 | } |
144 | } |
145 | |
146 | return true; |
147 | } |
148 | |
149 | int main(int, char**) { |
150 | test(); |
151 | static_assert(test()); |
152 | |
153 | return 0; |
154 | } |
155 | |