cxx/test/containers/unord/unord.map/bucket.pass.cpp

//===----------------------------------------------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

// <unordered_map>

// template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
//           class Alloc = allocator<pair<const Key, T>>>
// class unordered_map

// size_type bucket(const key_type& __k) const;

#include <unordered_map>
#include <string>
#include <cassert>

int main()
{
    {
        typedef std::unordered_map<int, std::string> C;
        typedef std::pair<int, std::string> P;
        P a[] =
        {
            P(1, "one"),
            P(2, "two"),
            P(3, "three"),
            P(4, "four"),
            P(1, "four"),
            P(2, "four"),
        };
        const C c(std::begin(a), std::end(a));
        size_t bc = c.bucket_count();
        assert(bc >= 5);
        for (size_t i = 0; i < 13; ++i)
            assert(c.bucket(i) == i % bc);
    }
}