libcxx/test/std/algorithms/alg.modifying.operations/alg.rotate/rotate_copy.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 // <algorithm>
  10
  11 // template<ForwardIterator InIter, OutputIterator<auto, InIter::reference> OutIter>
  12 //   constexpr OutIter          // constexpr after C++17
  13 //   rotate_copy(InIter first, InIter middle, InIter last, OutIter result);
  14
  15 // Older compilers don't support std::is_constant_evaluated
  16 // UNSUPPORTED: clang-4, clang-5, clang-6, clang-7, clang-8
  17 // UNSUPPORTED: apple-clang-9, apple-clang-10
  18
  19 #include <algorithm>
  20 #include <cassert>
  21
  22 #include "test_macros.h"
  23 #include "test_iterators.h"
  24
  25
  26 template <class InIter, class OutIter>
  27 TEST_CONSTEXPR_CXX20 void test() {
  28   int ia[] = {0, 1, 2, 3};
  29   const unsigned sa = sizeof(ia) / sizeof(ia[0]);
  30   int ib[sa] = {0};
  31
  32   OutIter r = std::rotate_copy(InIter(ia), InIter(ia), InIter(ia), OutIter(ib));
  33   assert(base(r) == ib);
  34
  35   r = std::rotate_copy(InIter(ia), InIter(ia), InIter(ia + 1), OutIter(ib));
  36   assert(base(r) == ib + 1);
  37   assert(ib[0] == 0);
  38
  39   r = std::rotate_copy(InIter(ia), InIter(ia + 1), InIter(ia + 1), OutIter(ib));
  40   assert(base(r) == ib + 1);
  41   assert(ib[0] == 0);
  42
  43   r = std::rotate_copy(InIter(ia), InIter(ia), InIter(ia + 2), OutIter(ib));
  44   assert(base(r) == ib + 2);
  45   assert(ib[0] == 0);
  46   assert(ib[1] == 1);
  47
  48   r = std::rotate_copy(InIter(ia), InIter(ia + 1), InIter(ia + 2), OutIter(ib));
  49   assert(base(r) == ib + 2);
  50   assert(ib[0] == 1);
  51   assert(ib[1] == 0);
  52
  53   r = std::rotate_copy(InIter(ia), InIter(ia + 2), InIter(ia + 2), OutIter(ib));
  54   assert(base(r) == ib + 2);
  55   assert(ib[0] == 0);
  56   assert(ib[1] == 1);
  57
  58   r = std::rotate_copy(InIter(ia), InIter(ia), InIter(ia + 3), OutIter(ib));
  59   assert(base(r) == ib + 3);
  60   assert(ib[0] == 0);
  61   assert(ib[1] == 1);
  62   assert(ib[2] == 2);
  63
  64   r = std::rotate_copy(InIter(ia), InIter(ia + 1), InIter(ia + 3), OutIter(ib));
  65   assert(base(r) == ib + 3);
  66   assert(ib[0] == 1);
  67   assert(ib[1] == 2);
  68   assert(ib[2] == 0);
  69
  70   r = std::rotate_copy(InIter(ia), InIter(ia + 2), InIter(ia + 3), OutIter(ib));
  71   assert(base(r) == ib + 3);
  72   assert(ib[0] == 2);
  73   assert(ib[1] == 0);
  74   assert(ib[2] == 1);
  75
  76   r = std::rotate_copy(InIter(ia), InIter(ia + 3), InIter(ia + 3), OutIter(ib));
  77   assert(base(r) == ib + 3);
  78   assert(ib[0] == 0);
  79   assert(ib[1] == 1);
  80   assert(ib[2] == 2);
  81
  82   r = std::rotate_copy(InIter(ia), InIter(ia), InIter(ia + 4), OutIter(ib));
  83   assert(base(r) == ib + 4);
  84   assert(ib[0] == 0);
  85   assert(ib[1] == 1);
  86   assert(ib[2] == 2);
  87   assert(ib[3] == 3);
  88
  89   r = std::rotate_copy(InIter(ia), InIter(ia + 1), InIter(ia + 4), OutIter(ib));
  90   assert(base(r) == ib + 4);
  91   assert(ib[0] == 1);
  92   assert(ib[1] == 2);
  93   assert(ib[2] == 3);
  94   assert(ib[3] == 0);
  95
  96   r = std::rotate_copy(InIter(ia), InIter(ia + 2), InIter(ia + 4), OutIter(ib));
  97   assert(base(r) == ib + 4);
  98   assert(ib[0] == 2);
  99   assert(ib[1] == 3);
 100   assert(ib[2] == 0);
 101   assert(ib[3] == 1);
 102
 103   r = std::rotate_copy(InIter(ia), InIter(ia + 3), InIter(ia + 4), OutIter(ib));
 104   assert(base(r) == ib + 4);
 105   assert(ib[0] == 3);
 106   assert(ib[1] == 0);
 107   assert(ib[2] == 1);
 108   assert(ib[3] == 2);
 109
 110   r = std::rotate_copy(InIter(ia), InIter(ia + 4), InIter(ia + 4), OutIter(ib));
 111   assert(base(r) == ib + 4);
 112   assert(ib[0] == 0);
 113   assert(ib[1] == 1);
 114   assert(ib[2] == 2);
 115   assert(ib[3] == 3);
 116
 117   {
 118     int ints[] = {1, 3, 5, 2, 5, 6};
 119     int const n_ints = sizeof(ints)/sizeof(int);
 120     int zeros[n_ints] = {0};
 121
 122     const size_t N = 2;
 123     const auto middle = std::begin(ints) + N;
 124     auto it = std::rotate_copy(std::begin(ints), middle, std::end(ints), std::begin(zeros));
 125     assert(std::distance(std::begin(zeros), it) == n_ints);
 126     assert(std::equal(std::begin(ints), middle, std::begin(zeros) + n_ints - N));
 127     assert(std::equal(middle, std::end(ints), std::begin(zeros)));
 128   }
 129 }
 130
 131 TEST_CONSTEXPR_CXX20 bool all_tests() {
 132   test<bidirectional_iterator<const int*>, output_iterator<int*> >();
 133   test<bidirectional_iterator<const int*>, forward_iterator<int*> >();
 134   test<bidirectional_iterator<const int*>, bidirectional_iterator<int*> >();
 135   test<bidirectional_iterator<const int*>, random_access_iterator<int*> >();
 136   test<bidirectional_iterator<const int*>, int*>();
 137
 138   test<random_access_iterator<const int*>, output_iterator<int*> >();
 139   test<random_access_iterator<const int*>, forward_iterator<int*> >();
 140   test<random_access_iterator<const int*>, bidirectional_iterator<int*> >();
 141   test<random_access_iterator<const int*>, random_access_iterator<int*> >();
 142   test<random_access_iterator<const int*>, int*>();
 143
 144   test<const int*, output_iterator<int*> >();
 145   test<const int*, forward_iterator<int*> >();
 146   test<const int*, bidirectional_iterator<int*> >();
 147   test<const int*, random_access_iterator<int*> >();
 148   test<const int*, int*>();
 149
 150   return true;
 151 }
 152
 153 int main(int, char**) {
 154   all_tests();
 155
 156 #if TEST_STD_VER > 17
 157   static_assert(all_tests());
 158 #endif
 159   return 0;
 160 }