//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//

// <vector>

// iterator       begin();
// iterator       end();
// const_iterator begin()  const;
// const_iterator end()    const;
// const_iterator cbegin() const;
// const_iterator cend()   const;

#include <vector>
#include <cassert>
#include <iterator>

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

struct A
{
    int first;
    int second;
};

TEST_CONSTEXPR_CXX20 bool tests()
{
    {
        typedef int T;
        typedef std::vector<T> C;
        C c;
        C::iterator i = c.begin();
        C::iterator j = c.end();
        assert(std::distance(i, j) == 0);
        assert(i == j);
    }
    {
        typedef int T;
        typedef std::vector<T> C;
        const C c;
        C::const_iterator i = c.begin();
        C::const_iterator j = c.end();
        assert(std::distance(i, j) == 0);
        assert(i == j);
    }
    {
        typedef int T;
        typedef std::vector<T> C;
        C c;
        C::const_iterator i = c.cbegin();
        C::const_iterator j = c.cend();
        assert(std::distance(i, j) == 0);
        assert(i == j);
        assert(i == c.end());
    }
    {
        typedef int T;
        typedef std::vector<T> C;
        const T t[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
        C c(std::begin(t), std::end(t));
        C::iterator i = c.begin();
        assert(*i == 0);
        ++i;
        assert(*i == 1);
        *i = 10;
        assert(*i == 10);
        assert(std::distance(c.begin(), c.end()) == 10);
    }
    {
        typedef int T;
        typedef std::vector<T> C;
        C::iterator i;
        C::const_iterator j;
        (void) i;
        (void) j;
    }
#if TEST_STD_VER >= 11
    {
        typedef int T;
        typedef std::vector<T, min_allocator<T>> C;
        C c;
        C::iterator i = c.begin();
        C::iterator j = c.end();
        assert(std::distance(i, j) == 0);

        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
    }
    {
        typedef int T;
        typedef std::vector<T, min_allocator<T>> C;
        const C c;
        C::const_iterator i = c.begin();
        C::const_iterator j = c.end();
        assert(std::distance(i, j) == 0);

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

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

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

#  if TEST_STD_VER >= 20
        // 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
    }
    {
        typedef int T;
        typedef std::vector<T, min_allocator<T>> C;
        C c;
        C::const_iterator i = c.cbegin();
        C::const_iterator j = c.cend();
        assert(std::distance(i, j) == 0);
        assert(i == j);
        assert(i == c.end());
    }
    {
        typedef int T;
        typedef std::vector<T, min_allocator<T>> C;
        const T t[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
        C c(std::begin(t), std::end(t));
        C::iterator i = c.begin();
        assert(*i == 0);
        ++i;
        assert(*i == 1);
        *i = 10;
        assert(*i == 10);
        assert(std::distance(c.begin(), c.end()) == 10);
    }
    {
        typedef int T;
        typedef std::vector<T, min_allocator<T>> C;
        C::iterator i;
        C::const_iterator j;
        (void) i;
        (void) j;
    }
    {
        typedef A T;
        typedef std::vector<T, min_allocator<T>> C;
        C c = {A{1, 2}};
        C::iterator i = c.begin();
        i->first = 3;
        C::const_iterator j = i;
        assert(j->first == 3);
    }
#endif
#if TEST_STD_VER > 11
    { // N3644 testing
        typedef std::vector<int> C;
        C::iterator ii1{}, ii2{};
        C::iterator ii4 = ii1;
        C::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);
#  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 // TEST_STD_VER > 11

    return true;
}

int main(int, char**)
{
    tests();
#if TEST_STD_VER > 17
    static_assert(tests());
#endif
    return 0;
}