xref: /llvm-project/libcxx/test/std/containers/sequences/array/iterators.pass.cpp (revision 77b9abfc8e89ca627e4f9a1cc206bea131db6db1)
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 // <array>
10 
11 // iterator begin() noexcept;                         // constexpr in C++17
12 // const_iterator begin() const noexcept;             // constexpr in C++17
13 // iterator end() noexcept;                           // constexpr in C++17
14 // const_iterator end() const noexcept;               // constexpr in C++17
15 //
16 // reverse_iterator rbegin() noexcept;                // constexpr in C++17
17 // const_reverse_iterator rbegin() const noexcept;    // constexpr in C++17
18 // reverse_iterator rend() noexcept;                  // constexpr in C++17
19 // const_reverse_iterator rend() const noexcept;      // constexpr in C++17
20 //
21 // const_iterator cbegin() const noexcept;            // constexpr in C++17
22 // const_iterator cend() const noexcept;              // constexpr in C++17
23 // const_reverse_iterator crbegin() const noexcept;   // constexpr in C++17
24 // const_reverse_iterator crend() const noexcept;     // constexpr in C++17
25 
26 #include <array>
27 #include <iterator>
28 #include <cassert>
29 
30 #include "test_macros.h"
31 
32 // std::array is explicitly allowed to be initialized with A a = { init-list };.
33 // Disable the missing braces warning for this reason.
34 #include "disable_missing_braces_warning.h"
35 
36 struct NoDefault {
37     TEST_CONSTEXPR NoDefault(int) { }
38 };
39 
40 TEST_CONSTEXPR_CXX17 bool tests()
41 {
42     {
43         typedef std::array<int, 5> C;
44         C array = {};
45         typename C::iterator i = array.begin();
46         typename C::const_iterator j = array.cbegin();
47         assert(i == j);
48     }
49     {
50         typedef std::array<int, 0> C;
51         C array = {};
52         typename C::iterator i = array.begin();
53         typename C::const_iterator j = array.cbegin();
54         assert(i == j);
55         LIBCPP_ASSERT(i != nullptr);
56         LIBCPP_ASSERT(j != nullptr);
57     }
58 
59     {
60         typedef std::array<int, 0> C;
61         C array = {};
62         typename C::iterator i = array.begin();
63         typename C::const_iterator j = array.cbegin();
64         assert(i == array.end());
65         assert(j == array.cend());
66         LIBCPP_ASSERT(i != nullptr);
67         LIBCPP_ASSERT(j != nullptr);
68     }
69     {
70         typedef std::array<int, 1> C;
71         C array = {1};
72         typename C::iterator i = array.begin();
73         assert(*i == 1);
74         assert(&*i == array.data());
75         *i = 99;
76         assert(array[0] == 99);
77     }
78     {
79         typedef std::array<int, 2> C;
80         C array = {1, 2};
81         typename C::iterator i = array.begin();
82         assert(*i == 1);
83         assert(&*i == array.data());
84         *i = 99;
85         assert(array[0] == 99);
86         assert(array[1] == 2);
87     }
88     {
89         typedef std::array<double, 3> C;
90         C array = {1, 2, 3.5};
91         typename C::iterator i = array.begin();
92         assert(*i == 1);
93         assert(&*i == array.data());
94         *i = 5.5;
95         assert(array[0] == 5.5);
96         assert(array[1] == 2.0);
97     }
98     {
99         typedef std::array<NoDefault, 0> C;
100         C array = {};
101         typename C::iterator ib = array.begin();
102         typename C::iterator ie = array.end();
103         assert(ib == ie);
104         LIBCPP_ASSERT(ib != nullptr);
105         LIBCPP_ASSERT(ie != nullptr);
106     }
107 
108 #if TEST_STD_VER >= 14
109     { // N3644 testing
110         {
111             typedef std::array<int, 5> C;
112             C::iterator ii1{}, ii2{};
113             C::iterator ii4 = ii1;
114             C::const_iterator cii{};
115             assert(ii1 == ii2);
116             assert(ii1 == ii4);
117             assert(ii1 == cii);
118 
119             assert(!(ii1 != ii2));
120             assert(!(ii1 != cii));
121 
122             C c = {};
123             assert(c.begin()   == std::begin(c));
124             assert(c.cbegin()  == std::cbegin(c));
125             assert(c.rbegin()  == std::rbegin(c));
126             assert(c.crbegin() == std::crbegin(c));
127             assert(c.end()     == std::end(c));
128             assert(c.cend()    == std::cend(c));
129             assert(c.rend()    == std::rend(c));
130             assert(c.crend()   == std::crend(c));
131 
132             assert(std::begin(c)   != std::end(c));
133             assert(std::rbegin(c)  != std::rend(c));
134             assert(std::cbegin(c)  != std::cend(c));
135             assert(std::crbegin(c) != std::crend(c));
136         }
137         {
138             typedef std::array<int, 0> C;
139             C::iterator ii1{}, ii2{};
140             C::iterator ii4 = ii1;
141             C::const_iterator cii{};
142             assert(ii1 == ii2);
143             assert(ii1 == ii4);
144 
145             assert(!(ii1 != ii2));
146 
147             assert( (ii1 == cii));
148             assert( (cii == ii1));
149             assert(!(ii1 != cii));
150             assert(!(cii != ii1));
151             assert(!(ii1 <  cii));
152             assert(!(cii <  ii1));
153             assert( (ii1 <= cii));
154             assert( (cii <= ii1));
155             assert(!(ii1 >  cii));
156             assert(!(cii >  ii1));
157             assert( (ii1 >= cii));
158             assert( (cii >= ii1));
159             assert(cii - ii1 == 0);
160             assert(ii1 - cii == 0);
161 
162             C c = {};
163             assert(c.begin()   == std::begin(c));
164             assert(c.cbegin()  == std::cbegin(c));
165             assert(c.rbegin()  == std::rbegin(c));
166             assert(c.crbegin() == std::crbegin(c));
167             assert(c.end()     == std::end(c));
168             assert(c.cend()    == std::cend(c));
169             assert(c.rend()    == std::rend(c));
170             assert(c.crend()   == std::crend(c));
171 
172             assert(std::begin(c)   == std::end(c));
173             assert(std::rbegin(c)  == std::rend(c));
174             assert(std::cbegin(c)  == std::cend(c));
175             assert(std::crbegin(c) == std::crend(c));
176         }
177     }
178 #endif
179     return true;
180 }
181 
182 int main(int, char**)
183 {
184     tests();
185 #if TEST_STD_VER >= 17
186     static_assert(tests(), "");
187 #endif
188   return 0;
189 }
190