libcxx/test/std/algorithms/alg.nonmodifying/alg.adjacent.find/adjacent_find_pred.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 Iter, EquivalenceRelation<auto, Iter::value_type> Pred>
  12 //   requires CopyConstructible<Pred>
  13 //   constexpr Iter  // constexpr after C++17
  14 //   adjacent_find(Iter first, Iter last, Pred pred);
  15
  16 #include <algorithm>
  17 #include <functional>
  18 #include <cassert>
  19
  20 #include "test_macros.h"
  21 #include "test_iterators.h"
  22
  23
  24 #if TEST_STD_VER > 17
  25 TEST_CONSTEXPR bool eq (int a, int b) { return a == b; }
  26
  27 TEST_CONSTEXPR bool test_constexpr() {
  28     int ia[] = {0, 1, 2, 2, 0, 1, 2, 3};
  29     int ib[] = {0, 1, 2, 7, 0, 1, 2, 3};
  30
  31     return  (std::adjacent_find(std::begin(ia), std::end(ia), eq) == ia+2)
  32          && (std::adjacent_find(std::begin(ib), std::end(ib), eq) == std::end(ib))
  33          ;
  34     }
  35 #endif
  36
  37 int main(int, char**)
  38 {
  39     int ia[] = {0, 1, 2, 2, 0, 1, 2, 3};
  40     const unsigned sa = sizeof(ia)/sizeof(ia[0]);
  41     assert(std::adjacent_find(forward_iterator<const int*>(ia),
  42                               forward_iterator<const int*>(ia + sa),
  43                               std::equal_to<int>()) ==
  44                               forward_iterator<const int*>(ia+2));
  45     assert(std::adjacent_find(forward_iterator<const int*>(ia),
  46                               forward_iterator<const int*>(ia),
  47                               std::equal_to<int>()) ==
  48                               forward_iterator<const int*>(ia));
  49     assert(std::adjacent_find(forward_iterator<const int*>(ia+3),
  50                               forward_iterator<const int*>(ia + sa),
  51                               std::equal_to<int>()) ==
  52                               forward_iterator<const int*>(ia+sa));
  53
  54 #if TEST_STD_VER > 17
  55     static_assert(test_constexpr());
  56 #endif
  57
  58   return 0;
  59 }