libcxx/test/std/iterators/predef.iterators/counted.iterator/iter_swap.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<indirectly_swappable<I> I2>
  12 //   friend constexpr void
  13 //     iter_swap(const counted_iterator& x, const counted_iterator<I2>& y)
  14 //       noexcept(noexcept(ranges::iter_swap(x.current, y.current)));
  15
  16 #include <iterator>
  17
  18 #include "test_macros.h"
  19 #include "test_iterators.h"
  20
  21 template<bool IsNoexcept>
  22 class HasNoexceptIterSwap
  23 {
  24   int *it_;
  25
  26 public:
  27   typedef          std::input_iterator_tag                      iterator_category;
  28   typedef int                                                   value_type;
  29   typedef typename std::iterator_traits<int *>::difference_type difference_type;
  30   typedef int *                                                 pointer;
  31   typedef int &                                                 reference;
  32
  33   constexpr int *base() const {return it_;}
  34
  35   HasNoexceptIterSwap() = default;
  36   explicit constexpr HasNoexceptIterSwap(int *it) : it_(it) {}
  37
  38   constexpr reference operator*() const {return *it_;}
  39
  40   constexpr HasNoexceptIterSwap& operator++() {++it_; return *this;}
  41   constexpr HasNoexceptIterSwap operator++(int)
  42       {HasNoexceptIterSwap tmp(*this); ++(*this); return tmp;}
  43
  44   friend void iter_swap(
  45     const HasNoexceptIterSwap&, const HasNoexceptIterSwap&) noexcept(IsNoexcept) {}
  46 };
  47
  48 constexpr bool test() {
  49   int buffer[8] = {1, 2, 3, 4, 5, 6, 7, 8};
  50
  51   {
  52     auto iter1 = cpp17_input_iterator<int*>(buffer);
  53     auto commonIter1 = std::counted_iterator<decltype(iter1)>(iter1, 8);
  54     auto commonIter2 = std::counted_iterator<decltype(iter1)>(iter1, 8);
  55     for (auto i = 0; i < 4; ++i) ++commonIter2;
  56     assert(*commonIter2 == 5);
  57     std::ranges::iter_swap(commonIter1, commonIter2);
  58     assert(*commonIter1 == 5);
  59     assert(*commonIter2 == 1);
  60     std::ranges::iter_swap(commonIter2, commonIter1);
  61   }
  62   {
  63     auto iter1 = forward_iterator<int*>(buffer);
  64     auto commonIter1 = std::counted_iterator<decltype(iter1)>(iter1, 8);
  65     auto commonIter2 = std::counted_iterator<decltype(iter1)>(iter1, 8);
  66     for (auto i = 0; i < 4; ++i) ++commonIter2;
  67     assert(*commonIter2 == 5);
  68     std::ranges::iter_swap(commonIter1, commonIter2);
  69     assert(*commonIter1 == 5);
  70     assert(*commonIter2 == 1);
  71     std::ranges::iter_swap(commonIter2, commonIter1);
  72   }
  73   {
  74     auto iter1 = random_access_iterator<int*>(buffer);
  75     auto commonIter1 = std::counted_iterator<decltype(iter1)>(iter1, 8);
  76     auto commonIter2 = std::counted_iterator<decltype(iter1)>(iter1, 8);
  77     for (auto i = 0; i < 4; ++i) ++commonIter2;
  78     assert(*commonIter2 == 5);
  79     std::ranges::iter_swap(commonIter1, commonIter2);
  80     assert(*commonIter1 == 5);
  81     assert(*commonIter2 == 1);
  82     std::ranges::iter_swap(commonIter2, commonIter1);
  83   }
  84
  85   // Test noexceptness.
  86   {
  87     static_assert( noexcept(std::ranges::iter_swap(
  88       std::declval<std::counted_iterator<HasNoexceptIterSwap<true>>&>(),
  89       std::declval<std::counted_iterator<HasNoexceptIterSwap<true>>&>()
  90     )));
  91     static_assert(!noexcept(std::ranges::iter_swap(
  92       std::declval<std::counted_iterator<HasNoexceptIterSwap<false>>&>(),
  93       std::declval<std::counted_iterator<HasNoexceptIterSwap<false>>&>()
  94     )));
  95   }
  96
  97   return true;
  98 }
  99
 100 int main(int, char**) {
 101   test();
 102   static_assert(test());
 103
 104   return 0;
 105 }