libcxx/test/std/containers/sequences/deque/iterators.pass.cpp

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

// <deque>

// Test nested types and default template args:

// template <class T, class Allocator = allocator<T> >
// class deque;

// iterator, const_iterator

#include <deque>
#include <iterator>
#include <cassert>

#include "test_macros.h"
#include "min_allocator.h"

int main(int, char**) {
  {
    typedef std::deque<int> C;
    C c;
    C::iterator i;
    i = c.begin();
    C::const_iterator j;
    j = c.cbegin();
    assert(i == j);
  }
#if TEST_STD_VER >= 11
  {
    typedef std::deque<int, min_allocator<int>> C;
    C c;
    C::iterator i;
    i = c.begin();
    C::const_iterator j;
    j = c.cbegin();

    assert(i == j);
    assert(!(i != j));

    assert(!(i < j));
    assert((i <= j));

    assert(!(i > j));
    assert((i >= j));

#  if TEST_STD_VER >= 20
    // P1614 + LWG3352
    // When the allocator does not have operator<=> then the iterator uses a
    // fallback to provide operator<=>.
    // Make sure to test with an allocator that does not have operator<=>.
    static_assert(!std::three_way_comparable<min_allocator<int>, std::strong_ordering>);
    static_assert(std::three_way_comparable<typename C::iterator, std::strong_ordering>);

    std::same_as<std::strong_ordering> decltype(auto) r1 = i <=> j;
    assert(r1 == std::strong_ordering::equal);
#  endif
  }
#endif
#if TEST_STD_VER > 11
  { // N3644 testing
    std::deque<int>::iterator ii1{}, ii2{};
    std::deque<int>::iterator ii4 = ii1;
    std::deque<int>::const_iterator cii{};
    assert(ii1 == ii2);
    assert(ii1 == ii4);

    assert(!(ii1 != ii2));

    assert((ii1 == cii));
    assert((cii == ii1));
    assert(!(ii1 != cii));
    assert(!(cii != ii1));
    assert(!(ii1 < cii));
    assert(!(cii < ii1));
    assert((ii1 <= cii));
    assert((cii <= ii1));
    assert(!(ii1 > cii));
    assert(!(cii > ii1));
    assert((ii1 >= cii));
    assert((cii >= ii1));
    assert(cii - ii1 == 0);
    assert(ii1 - cii == 0);

    //         std::deque<int> c;
    //         assert ( ii1 != c.cbegin());
    //         assert ( cii != c.begin());
    //         assert ( cii != c.cend());
    //         assert ( ii1 != c.end());

#  if TEST_STD_VER >= 20
    // P1614 + LWG3352
    std::same_as<std::strong_ordering> decltype(auto) r1 = ii1 <=> ii2;
    assert(r1 == std::strong_ordering::equal);

    std::same_as<std::strong_ordering> decltype(auto) r2 = cii <=> ii2;
    assert(r2 == std::strong_ordering::equal);
#  endif // TEST_STD_VER > 20
  }
#endif

  return 0;
}