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 template<typename C>
42 void test_const_container( const C & c, typename C::value_type val ) {
43     assert ( std::begin(c)   == c.begin());
44     assert (*std::begin(c)   ==  val );
45     assert ( std::begin(c)   != c.end());
46     assert ( std::end(c)     == c.end());
47 #if TEST_STD_VER > 11
48     assert ( std::cbegin(c)  == c.cbegin());
49     assert ( std::cbegin(c)  != c.cend());
50     assert ( std::cend(c)    == c.cend());
51     assert ( std::rbegin(c)  == c.rbegin());
52     assert ( std::rbegin(c)  != c.rend());
53     assert ( std::rend(c)    == c.rend());
54     assert ( std::crbegin(c) == c.crbegin());
55     assert ( std::crbegin(c) != c.crend());
56     assert ( std::crend(c)   == c.crend());
57 #endif
58     }
59 
60 template<typename T>
61 void test_const_container( const std::initializer_list<T> & c, T val ) {
62     assert ( std::begin(c)   == c.begin());
63     assert (*std::begin(c)   ==  val );
64     assert ( std::begin(c)   != c.end());
65     assert ( std::end(c)     == c.end());
66 #if TEST_STD_VER > 11
67 //  initializer_list doesn't have cbegin/cend/rbegin/rend
68 //  but std::cbegin(),etc work (b/c they're general fn templates)
69 //     assert ( std::cbegin(c)  == c.cbegin());
70 //     assert ( std::cbegin(c)  != c.cend());
71 //     assert ( std::cend(c)    == c.cend());
72 //     assert ( std::rbegin(c)  == c.rbegin());
73 //     assert ( std::rbegin(c)  != c.rend());
74 //     assert ( std::rend(c)    == c.rend());
75 //     assert ( std::crbegin(c) == c.crbegin());
76 //     assert ( std::crbegin(c) != c.crend());
77 //     assert ( std::crend(c)   == c.crend());
78 #endif
79     }
80 
81 template<typename C>
82 void test_container( C & c, typename C::value_type val ) {
83     assert ( std::begin(c)   == c.begin());
84     assert (*std::begin(c)   ==  val );
85     assert ( std::begin(c)   != c.end());
86     assert ( std::end(c)     == c.end());
87 #if TEST_STD_VER > 11
88     assert ( std::cbegin(c)  == c.cbegin());
89     assert ( std::cbegin(c)  != c.cend());
90     assert ( std::cend(c)    == c.cend());
91     assert ( std::rbegin(c)  == c.rbegin());
92     assert ( std::rbegin(c)  != c.rend());
93     assert ( std::rend(c)    == c.rend());
94     assert ( std::crbegin(c) == c.crbegin());
95     assert ( std::crbegin(c) != c.crend());
96     assert ( std::crend(c)   == c.crend());
97 #endif
98     }
99 
100 template<typename T>
101 void test_container( std::initializer_list<T> & c, T val ) {
102     assert ( std::begin(c)   == c.begin());
103     assert (*std::begin(c)   ==  val );
104     assert ( std::begin(c)   != c.end());
105     assert ( std::end(c)     == c.end());
106 #if TEST_STD_VER > 11
107 //  initializer_list doesn't have cbegin/cend/rbegin/rend
108 //     assert ( std::cbegin(c)  == c.cbegin());
109 //     assert ( std::cbegin(c)  != c.cend());
110 //     assert ( std::cend(c)    == c.cend());
111 //     assert ( std::rbegin(c)  == c.rbegin());
112 //     assert ( std::rbegin(c)  != c.rend());
113 //     assert ( std::rend(c)    == c.rend());
114 //     assert ( std::crbegin(c) == c.crbegin());
115 //     assert ( std::crbegin(c) != c.crend());
116 //     assert ( std::crend(c)   == c.crend());
117 #endif
118     }
119 
120 template<typename T, size_t Sz>
121 void test_const_array( const T (&array)[Sz] ) {
122     assert ( std::begin(array)  == array );
123     assert (*std::begin(array)  ==  array[0] );
124     assert ( std::begin(array)  != std::end(array));
125     assert ( std::end(array)    == array + Sz);
126 #if TEST_STD_VER > 11
127     assert ( std::cbegin(array) == array );
128     assert (*std::cbegin(array) == array[0] );
129     assert ( std::cbegin(array) != std::cend(array));
130     assert ( std::cend(array)   == array + Sz);
131 #endif
132     }
133 
134 int main(int, char**) {
135     std::vector<int> v; v.push_back(1);
136     std::list<int> l;   l.push_back(2);
137     std::array<int, 1> a; a[0] = 3;
138     std::initializer_list<int> il = { 4 };
139 
140     test_container ( v, 1 );
141     test_container ( l, 2 );
142     test_container ( a, 3 );
143     test_container ( il, 4 );
144 
145     test_const_container ( v, 1 );
146     test_const_container ( l, 2 );
147     test_const_container ( a, 3 );
148     test_const_container ( il, 4 );
149 
150     static constexpr int arrA [] { 1, 2, 3 };
151     test_const_array ( arrA );
152 #if TEST_STD_VER > 11
153     constexpr const int *b = std::cbegin(arrA);
154     constexpr const int *e = std::cend(arrA);
155     static_assert(e - b == 3, "");
156 #endif
157 
158 #if TEST_STD_VER > 14
159     {
160         typedef std::array<int, 5> C;
161         constexpr const C c{0,1,2,3,4};
162 
163         static_assert ( c.begin()   == std::begin(c), "");
164         static_assert ( c.cbegin()  == std::cbegin(c), "");
165         static_assert ( c.end()     == std::end(c), "");
166         static_assert ( c.cend()    == std::cend(c), "");
167 
168         static_assert ( c.rbegin()  == std::rbegin(c), "");
169         static_assert ( c.crbegin() == std::crbegin(c), "");
170         static_assert ( c.rend()    == std::rend(c), "");
171         static_assert ( c.crend()   == std::crend(c), "");
172 
173         static_assert ( std::begin(c)   != std::end(c), "");
174         static_assert ( std::rbegin(c)  != std::rend(c), "");
175         static_assert ( std::cbegin(c)  != std::cend(c), "");
176         static_assert ( std::crbegin(c) != std::crend(c), "");
177 
178         static_assert ( *c.begin()  == 0, "");
179         static_assert ( *c.rbegin()  == 4, "");
180 
181         static_assert ( *std::begin(c)   == 0, "" );
182         static_assert ( *std::cbegin(c)  == 0, "" );
183         static_assert ( *std::rbegin(c)  == 4, "" );
184         static_assert ( *std::crbegin(c) == 4, "" );
185     }
186 
187     {
188         static constexpr const int c[] = {0,1,2,3,4};
189 
190         static_assert ( *std::begin(c)   == 0, "" );
191         static_assert ( *std::cbegin(c)  == 0, "" );
192         static_assert ( *std::rbegin(c)  == 4, "" );
193         static_assert ( *std::crbegin(c) == 4, "" );
194     }
195 #endif
196 
197   return 0;
198 }
199