libcxx/test/std/algorithms/alg.nonmodifying/alg.count/count.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<InputIterator Iter, class T>
  12 //   requires HasEqualTo<Iter::value_type, T>
  13 //   constexpr Iter::difference_type   // constexpr after C++17
  14 //   count(Iter first, Iter last, const T& value);
  15
  16 #include <algorithm>
  17 #include <cassert>
  18
  19 #include "test_macros.h"
  20 #include "test_iterators.h"
  21
  22 #if TEST_STD_VER > 17
  23 TEST_CONSTEXPR bool test_constexpr() {
  24     int ia[] = {0, 1, 2, 2, 0, 1, 2, 3};
  25     int ib[] = {1, 2, 3, 4, 5, 6};
  26     return    (std::count(std::begin(ia), std::end(ia), 2) == 3)
  27            && (std::count(std::begin(ib), std::end(ib), 9) == 0)
  28            ;
  29     }
  30 #endif
  31
  32 int main(int, char**)
  33 {
  34     int ia[] = {0, 1, 2, 2, 0, 1, 2, 3};
  35     const unsigned sa = sizeof(ia)/sizeof(ia[0]);
  36     assert(std::count(input_iterator<const int*>(ia),
  37                       input_iterator<const int*>(ia + sa), 2) == 3);
  38     assert(std::count(input_iterator<const int*>(ia),
  39                       input_iterator<const int*>(ia + sa), 7) == 0);
  40     assert(std::count(input_iterator<const int*>(ia),
  41                       input_iterator<const int*>(ia), 2) == 0);
  42
  43 #if TEST_STD_VER > 17
  44     static_assert(test_constexpr());
  45 #endif
  46
  47   return 0;
  48 }