libcxx/test/std/iterators/predef.iterators/iterators.common/minus.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 // UNSUPPORTED: c++03, c++11, c++14, c++17
  10
  11 // template<sized_sentinel_for<I> I2, sized_sentinel_for<I> S2>
  12 //   requires sized_sentinel_for<S, I2>
  13 // friend iter_difference_t<I2> operator-(
  14 //   const common_iterator& x, const common_iterator<I2, S2>& y);
  15
  16 #include <iterator>
  17 #include <cassert>
  18
  19 #include "test_macros.h"
  20 #include "types.h"
  21
  22 void test() {
  23   int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
  24
  25   {
  26     auto iter1 = random_access_iterator<int*>(buffer);
  27     auto commonIter1 = std::common_iterator<decltype(iter1), sized_sentinel_type<int*>>(iter1);
  28     auto commonSent1 = std::common_iterator<decltype(iter1), sized_sentinel_type<int*>>(sized_sentinel_type<int*>{buffer + 8});
  29     assert(commonIter1 - commonSent1 == -8);
  30     assert(commonSent1 - commonIter1 == 8);
  31     assert(commonIter1 - commonIter1 == 0);
  32     assert(commonSent1 - commonSent1 == 0);
  33   }
  34   {
  35     auto iter1 = simple_iterator<int*>(buffer);
  36     auto iter2 = comparable_iterator<int*>(buffer);
  37     auto commonIter1 = std::common_iterator<decltype(iter1), sized_sentinel_type<int*>>(iter1);
  38     auto commonIter2 = std::common_iterator<decltype(iter2), sized_sentinel_type<int*>>(iter2);
  39
  40     assert(commonIter1 - commonIter2 == 0);
  41   }
  42   {
  43     auto iter1 = random_access_iterator<int*>(buffer);
  44     const auto commonIter1 = std::common_iterator<decltype(iter1), sized_sentinel_type<int*>>(iter1);
  45     const auto commonSent1 = std::common_iterator<decltype(iter1), sized_sentinel_type<int*>>(sized_sentinel_type<int*>{buffer + 8});
  46     assert(commonIter1 - commonSent1 == -8);
  47     assert(commonSent1 - commonIter1 == 8);
  48     assert(commonIter1 - commonIter1 == 0);
  49     assert(commonSent1 - commonSent1 == 0);
  50   }
  51   {
  52     auto iter1 = simple_iterator<int*>(buffer);
  53     auto iter2 = comparable_iterator<int*>(buffer);
  54     const auto commonIter1 = std::common_iterator<decltype(iter1), sized_sentinel_type<int*>>(iter1);
  55     const auto commonIter2 = std::common_iterator<decltype(iter2), sized_sentinel_type<int*>>(iter2);
  56
  57     assert(commonIter1 - commonIter2 == 0);
  58   }
  59 }
  60
  61 int main(int, char**) {
  62   test();
  63
  64   return 0;
  65 }