libcxx/test/std/iterators/iterator.range/begin-end.pass.cpp

   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 }