//===----------------------------------------------------------------------===//
//
// 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_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

// void rehash(size_type n);

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

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

template <class C>
void rehash_postcondition(const C& c, std::size_t n) {
  assert(c.bucket_count() >= c.size() / c.max_load_factor() && c.bucket_count() >= n);
}

template <class C>
void test(const C& c) {
  assert(c.size() == 4);
  assert(c.at(1) == "one");
  assert(c.at(2) == "two");
  assert(c.at(3) == "three");
  assert(c.at(4) == "four");
}

int main(int, char**) {
  {
    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"),
    };
    C c(a, a + sizeof(a) / sizeof(a[0]));
    test(c);
    assert(c.bucket_count() >= 5);
    c.rehash(3);
    rehash_postcondition(c, 3);
    LIBCPP_ASSERT(c.bucket_count() == 5);
    test(c);
    c.max_load_factor(2);
    c.rehash(3);
    rehash_postcondition(c, 3);
    LIBCPP_ASSERT(c.bucket_count() == 3);
    test(c);
    c.rehash(31);
    rehash_postcondition(c, 31);
    LIBCPP_ASSERT(c.bucket_count() == 31);
    test(c);
  }
#if TEST_STD_VER >= 11
  {
    typedef std::unordered_map<int,
                               std::string,
                               std::hash<int>,
                               std::equal_to<int>,
                               min_allocator<std::pair<const 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"),
    };
    C c(a, a + sizeof(a) / sizeof(a[0]));
    test(c);
    assert(c.bucket_count() >= 5);
    c.rehash(3);
    rehash_postcondition(c, 3);
    LIBCPP_ASSERT(c.bucket_count() == 5);
    test(c);
    c.max_load_factor(2);
    c.rehash(3);
    rehash_postcondition(c, 3);
    LIBCPP_ASSERT(c.bucket_count() == 3);
    test(c);
    c.rehash(31);
    rehash_postcondition(c, 31);
    LIBCPP_ASSERT(c.bucket_count() == 31);
    test(c);
  }
#endif

  return 0;
}