libcxx/test/std/iterators/predef.iterators/counted.iterator/arrow.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 // constexpr auto operator->() const noexcept
  12 //   requires contiguous_iterator<I>;
  13
  14 #include <iterator>
  15
  16 #include "test_macros.h"
  17 #include "test_iterators.h"
  18
  19 template<class Iter>
  20 concept ArrowEnabled = requires(Iter& iter) {
  21   iter.operator->();
  22 };
  23
  24 constexpr bool test() {
  25   int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
  26
  27   {
  28     std::counted_iterator iter(contiguous_iterator<int*>{buffer}, 8);
  29     for (int i = 0; i < 8; ++i, ++iter)
  30       assert(iter.operator->() == buffer + i);
  31
  32     static_assert(noexcept(iter.operator->()));
  33   }
  34   {
  35     const std::counted_iterator iter(contiguous_iterator<int*>{buffer}, 8);
  36     assert(iter.operator->() == buffer);
  37
  38     static_assert(noexcept(iter.operator->()));
  39   }
  40
  41   {
  42       static_assert( ArrowEnabled<std::counted_iterator<contiguous_iterator<int*>>>);
  43       static_assert(!ArrowEnabled<std::counted_iterator<random_access_iterator<int*>>>);
  44   }
  45
  46   return true;
  47 }
  48
  49 int main(int, char**) {
  50   test();
  51   static_assert(test());
  52
  53   return 0;
  54 }