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 // XFAIL: c++03
10 
11 // <iterator>
12 // template <class C> constexpr auto begin(C& c) -> decltype(c.begin());
13 // template <class C> constexpr auto begin(const C& c) -> decltype(c.begin());
14 // template <class C> constexpr auto cbegin(const C& c) -> decltype(std::begin(c)); // C++14
15 // template <class C> constexpr auto cend(const C& c) -> decltype(std::end(c));     // C++14
16 // template <class C> constexpr auto end  (C& c) -> decltype(c.end());
17 // template <class C> constexpr auto end  (const C& c) -> decltype(c.end());
18 // template <class E> constexpr reverse_iterator<const E*> rbegin(initializer_list<E> il);
19 // template <class E> constexpr reverse_iterator<const E*> rend  (initializer_list<E> il);
20 //
21 // template <class C> auto constexpr rbegin(C& c) -> decltype(c.rbegin());                 // C++14
22 // template <class C> auto constexpr rbegin(const C& c) -> decltype(c.rbegin());           // C++14
23 // template <class C> auto constexpr rend(C& c) -> decltype(c.rend());                     // C++14
24 // template <class C> constexpr auto rend(const C& c) -> decltype(c.rend());               // C++14
25 // template <class T, size_t N> reverse_iterator<T*> constexpr rbegin(T (&array)[N]);      // C++14
26 // template <class T, size_t N> reverse_iterator<T*> constexpr rend(T (&array)[N]);        // C++14
27 // template <class C> constexpr auto crbegin(const C& c) -> decltype(std::rbegin(c));      // C++14
28 // template <class C> constexpr auto crend(const C& c) -> decltype(std::rend(c));          // C++14
29 //
30 //  All of these are constexpr in C++17
31 
32 #include "test_macros.h"
33 
34 #include <iterator>
35 #include <cassert>
36 #include <vector>
37 #include <array>
38 #include <list>
39 #include <initializer_list>
40 
41 // std::array is explicitly allowed to be initialized with A a = { init-list };.
42 // Disable the missing braces warning for this reason.
43 #include "disable_missing_braces_warning.h"
44 
45 template<typename C>
46 void test_const_container( const C & c, typename C::value_type val ) {
47     assert ( std::begin(c)   == c.begin());
48     assert (*std::begin(c)   ==  val );
49     assert ( std::begin(c)   != c.end());
50     assert ( std::end(c)     == c.end());
51 #if TEST_STD_VER > 11
52     assert ( std::cbegin(c)  == c.cbegin());
53     assert ( std::cbegin(c)  != c.cend());
54     assert ( std::cend(c)    == c.cend());
55     assert ( std::rbegin(c)  == c.rbegin());
56     assert ( std::rbegin(c)  != c.rend());
57     assert ( std::rend(c)    == c.rend());
58     assert ( std::crbegin(c) == c.crbegin());
59     assert ( std::crbegin(c) != c.crend());
60     assert ( std::crend(c)   == c.crend());
61 #endif
62     }
63 
64 template<typename T>
65 void test_const_container( const std::initializer_list<T> & c, T val ) {
66     assert ( std::begin(c)   == c.begin());
67     assert (*std::begin(c)   ==  val );
68     assert ( std::begin(c)   != c.end());
69     assert ( std::end(c)     == c.end());
70 #if TEST_STD_VER > 11
71 //  initializer_list doesn't have cbegin/cend/rbegin/rend
72 //  but std::cbegin(),etc work (b/c they're general fn templates)
73 //     assert ( std::cbegin(c)  == c.cbegin());
74 //     assert ( std::cbegin(c)  != c.cend());
75 //     assert ( std::cend(c)    == c.cend());
76 //     assert ( std::rbegin(c)  == c.rbegin());
77 //     assert ( std::rbegin(c)  != c.rend());
78 //     assert ( std::rend(c)    == c.rend());
79 //     assert ( std::crbegin(c) == c.crbegin());
80 //     assert ( std::crbegin(c) != c.crend());
81 //     assert ( std::crend(c)   == c.crend());
82 #endif
83     }
84 
85 template<typename C>
86 void test_container( C & c, typename C::value_type val ) {
87     assert ( std::begin(c)   == c.begin());
88     assert (*std::begin(c)   ==  val );
89     assert ( std::begin(c)   != c.end());
90     assert ( std::end(c)     == c.end());
91 #if TEST_STD_VER > 11
92     assert ( std::cbegin(c)  == c.cbegin());
93     assert ( std::cbegin(c)  != c.cend());
94     assert ( std::cend(c)    == c.cend());
95     assert ( std::rbegin(c)  == c.rbegin());
96     assert ( std::rbegin(c)  != c.rend());
97     assert ( std::rend(c)    == c.rend());
98     assert ( std::crbegin(c) == c.crbegin());
99     assert ( std::crbegin(c) != c.crend());
100     assert ( std::crend(c)   == c.crend());
101 #endif
102     }
103 
104 template<typename T>
105 void test_container( std::initializer_list<T> & c, T val ) {
106     assert ( std::begin(c)   == c.begin());
107     assert (*std::begin(c)   ==  val );
108     assert ( std::begin(c)   != c.end());
109     assert ( std::end(c)     == c.end());
110 #if TEST_STD_VER > 11
111 //  initializer_list doesn't have cbegin/cend/rbegin/rend
112 //     assert ( std::cbegin(c)  == c.cbegin());
113 //     assert ( std::cbegin(c)  != c.cend());
114 //     assert ( std::cend(c)    == c.cend());
115 //     assert ( std::rbegin(c)  == c.rbegin());
116 //     assert ( std::rbegin(c)  != c.rend());
117 //     assert ( std::rend(c)    == c.rend());
118 //     assert ( std::crbegin(c) == c.crbegin());
119 //     assert ( std::crbegin(c) != c.crend());
120 //     assert ( std::crend(c)   == c.crend());
121 #endif
122     }
123 
124 template<typename T, size_t Sz>
125 void test_const_array( const T (&array)[Sz] ) {
126     assert ( std::begin(array)  == array );
127     assert (*std::begin(array)  ==  array[0] );
128     assert ( std::begin(array)  != std::end(array));
129     assert ( std::end(array)    == array + Sz);
130 #if TEST_STD_VER > 11
131     assert ( std::cbegin(array) == array );
132     assert (*std::cbegin(array) == array[0] );
133     assert ( std::cbegin(array) != std::cend(array));
134     assert ( std::cend(array)   == array + Sz);
135 #endif
136     }
137 
138 int main(int, char**) {
139     std::vector<int> v; v.push_back(1);
140     std::list<int> l;   l.push_back(2);
141     std::array<int, 1> a; a[0] = 3;
142     std::initializer_list<int> il = { 4 };
143 
144     test_container ( v, 1 );
145     test_container ( l, 2 );
146     test_container ( a, 3 );
147     test_container ( il, 4 );
148 
149     test_const_container ( v, 1 );
150     test_const_container ( l, 2 );
151     test_const_container ( a, 3 );
152     test_const_container ( il, 4 );
153 
154     static constexpr int arrA [] { 1, 2, 3 };
155     test_const_array ( arrA );
156 #if TEST_STD_VER > 11
157     constexpr const int *b = std::cbegin(arrA);
158     constexpr const int *e = std::cend(arrA);
159     static_assert(e - b == 3, "");
160 #endif
161 
162 #if TEST_STD_VER > 14
163     {
164         typedef std::array<int, 5> C;
165         constexpr const C c{0,1,2,3,4};
166 
167         static_assert ( c.begin()   == std::begin(c), "");
168         static_assert ( c.cbegin()  == std::cbegin(c), "");
169         static_assert ( c.end()     == std::end(c), "");
170         static_assert ( c.cend()    == std::cend(c), "");
171 
172         static_assert ( c.rbegin()  == std::rbegin(c), "");
173         static_assert ( c.crbegin() == std::crbegin(c), "");
174         static_assert ( c.rend()    == std::rend(c), "");
175         static_assert ( c.crend()   == std::crend(c), "");
176 
177         static_assert ( std::begin(c)   != std::end(c), "");
178         static_assert ( std::rbegin(c)  != std::rend(c), "");
179         static_assert ( std::cbegin(c)  != std::cend(c), "");
180         static_assert ( std::crbegin(c) != std::crend(c), "");
181 
182         static_assert ( *c.begin()  == 0, "");
183         static_assert ( *c.rbegin()  == 4, "");
184 
185         static_assert ( *std::begin(c)   == 0, "" );
186         static_assert ( *std::cbegin(c)  == 0, "" );
187         static_assert ( *std::rbegin(c)  == 4, "" );
188         static_assert ( *std::crbegin(c) == 4, "" );
189     }
190 
191     {
192         static constexpr const int c[] = {0,1,2,3,4};
193 
194         static_assert ( *std::begin(c)   == 0, "" );
195         static_assert ( *std::cbegin(c)  == 0, "" );
196         static_assert ( *std::rbegin(c)  == 4, "" );
197         static_assert ( *std::crbegin(c) == 4, "" );
198     }
199 #endif
200 
201   return 0;
202 }
203