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

// <unordered_set>

// template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
//           class Alloc = allocator<Value>>
// class unordered_set

// local_iterator       begin (size_type n);
// local_iterator       end   (size_type n);
// const_local_iterator begin (size_type n) const;
// const_local_iterator end   (size_type n) const;
// const_local_iterator cbegin(size_type n) const;
// const_local_iterator cend  (size_type n) const;

#include <unordered_set>
#include <cassert>

int main(int, char**)
{
    {
        typedef std::unordered_set<int> C;
        typedef int P;
        typedef C::local_iterator I;
        P a[] =
        {
            P(1),
            P(2),
            P(3),
            P(4),
            P(1),
            P(2)
        };
        C c(a, a + sizeof(a)/sizeof(a[0]));
        assert(c.bucket_count() >= 5);
        C::size_type b = c.bucket(0);
        I i = c.begin(b);
        I j = c.end(b);
        assert(std::distance(i, j) == 0);

        b = c.bucket(1);
        i = c.begin(b);
        j = c.end(b);
        assert(std::distance(i, j) == 2);
        assert(*i == 1);
        ++i;
        assert(*i == 1);
        *i = 2;

        b = c.bucket(2);
        i = c.begin(b);
        j = c.end(b);
        assert(std::distance(i, j) == 2);
        assert(*i == 2);
        ++i;
        assert(*i == 2);

        b = c.bucket(3);
        i = c.begin(b);
        j = c.end(b);
        assert(std::distance(i, j) == 1);
        assert(*i == 3);

        b = c.bucket(4);
        i = c.begin(b);
        j = c.end(b);
        assert(std::distance(i, j) == 1);
        assert(*i == 4);

        b = c.bucket(5);
        i = c.begin(b);
        j = c.end(b);
        assert(std::distance(i, j) == 0);

        b = c.bucket(6);
        i = c.begin(b);
        j = c.end(b);
        assert(std::distance(i, j) == 0);
    }
    {
        typedef std::unordered_set<int> C;
        typedef int P;
        typedef C::const_local_iterator I;
        P a[] =
        {
            P(1),
            P(2),
            P(3),
            P(4),
            P(1),
            P(2)
        };
        const C c(a, a + sizeof(a)/sizeof(a[0]));
        assert(c.bucket_count() >= 5);
        C::size_type b = c.bucket(0);
        I i = c.begin(b);
        I j = c.end(b);
        assert(std::distance(i, j) == 0);

        b = c.bucket(1);
        i = c.begin(b);
        j = c.end(b);
        assert(std::distance(i, j) == 2);
        assert(*i == 1);
        ++i;
        assert(*i == 1);

        b = c.bucket(2);
        i = c.begin(b);
        j = c.end(b);
        assert(std::distance(i, j) == 2);
        assert(*i == 2);
        ++i;
        assert(*i == 2);

        b = c.bucket(3);
        i = c.begin(b);
        j = c.end(b);
        assert(std::distance(i, j) == 1);
        assert(*i == 3);

        b = c.bucket(4);
        i = c.begin(b);
        j = c.end(b);
        assert(std::distance(i, j) == 1);
        assert(*i == 4);

        b = c.bucket(5);
        i = c.begin(b);
        j = c.end(b);
        assert(std::distance(i, j) == 0);

        b = c.bucket(6);
        i = c.begin(b);
        j = c.end(b);
        assert(std::distance(i, j) == 0);
    }
    {
        typedef std::unordered_set<int> C;
        typedef int P;
        typedef C::const_local_iterator I;
        P a[] =
        {
            P(1),
            P(2),
            P(3),
            P(4),
            P(1),
            P(2)
        };
        C c(a, a + sizeof(a)/sizeof(a[0]));
        assert(c.bucket_count() >= 5);
        C::size_type b = c.bucket(0);
        I i = c.cbegin(b);
        I j = c.cend(b);
        assert(std::distance(i, j) == 0);

        b = c.bucket(1);
        i = c.cbegin(b);
        j = c.cend(b);
        assert(std::distance(i, j) == 2);
        assert(*i == 1);
        ++i;
        assert(*i == 1);

        b = c.bucket(2);
        i = c.cbegin(b);
        j = c.cend(b);
        assert(std::distance(i, j) == 2);
        assert(*i == 2);
        ++i;
        assert(*i == 2);

        b = c.bucket(3);
        i = c.cbegin(b);
        j = c.cend(b);
        assert(std::distance(i, j) == 1);
        assert(*i == 3);

        b = c.bucket(4);
        i = c.cbegin(b);
        j = c.cend(b);
        assert(std::distance(i, j) == 1);
        assert(*i == 4);

        b = c.bucket(5);
        i = c.cbegin(b);
        j = c.cend(b);
        assert(std::distance(i, j) == 0);

        b = c.bucket(6);
        i = c.cbegin(b);
        j = c.cend(b);
        assert(std::distance(i, j) == 0);
    }
    {
        typedef std::unordered_set<int> C;
        typedef int P;
        typedef C::const_local_iterator I;
        P a[] =
        {
            P(1),
            P(2),
            P(3),
            P(4),
            P(1),
            P(2)
        };
        const C c(a, a + sizeof(a)/sizeof(a[0]));
        assert(c.bucket_count() >= 5);
        C::size_type b = c.bucket(0);
        I i = c.cbegin(b);
        I j = c.cend(b);
        assert(std::distance(i, j) == 0);

        b = c.bucket(1);
        i = c.cbegin(b);
        j = c.cend(b);
        assert(std::distance(i, j) == 2);
        assert(*i == 1);
        ++i;
        assert(*i == 1);

        b = c.bucket(2);
        i = c.cbegin(b);
        j = c.cend(b);
        assert(std::distance(i, j) == 2);
        assert(*i == 2);
        ++i;
        assert(*i == 2);

        b = c.bucket(3);
        i = c.cbegin(b);
        j = c.cend(b);
        assert(std::distance(i, j) == 1);
        assert(*i == 3);

        b = c.bucket(4);
        i = c.cbegin(b);
        j = c.cend(b);
        assert(std::distance(i, j) == 1);
        assert(*i == 4);

        b = c.bucket(5);
        i = c.cbegin(b);
        j = c.cend(b);
        assert(std::distance(i, j) == 0);

        b = c.bucket(6);
        i = c.cbegin(b);
        j = c.cend(b);
        assert(std::distance(i, j) == 0);
    }

  return 0;
}