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

// iterator erase(const_iterator p)

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

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

struct TemplateConstructor {
  template <typename T>
  TemplateConstructor(const T&) {}
};

bool operator==(const TemplateConstructor&, const TemplateConstructor&) { return false; }
struct Hash {
  std::size_t operator()(const TemplateConstructor&) const { return 0; }
};

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]));
    C::const_iterator i = c.find(2);
    c.erase(i);
    assert(c.size() == 3);
    assert(c.at(1) == "one");
    assert(c.at(3) == "three");
    assert(c.at(4) == "four");
  }
#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]));
    C::const_iterator i = c.find(2);
    c.erase(i);
    assert(c.size() == 3);
    assert(c.at(1) == "one");
    assert(c.at(3) == "three");
    assert(c.at(4) == "four");
  }
#endif
#if TEST_STD_VER >= 14
  {
    //  This is LWG #2059
    typedef TemplateConstructor T;
    typedef std::unordered_map<T, int, Hash> C;
    typedef C::iterator I;

    C m;
    T a{0};
    I it = m.find(a);
    if (it != m.end())
      m.erase(it);
  }
#endif

  return 0;
}
