//===----------------------------------------------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// UNSUPPORTED: c++03, c++11, c++14

// <unordered_map>

// class unordered_map

// template <class... Args>
//  pair<iterator, bool> try_emplace(const key_type& k, Args&&... args);          // C++17
// template <class... Args>
//  pair<iterator, bool> try_emplace(key_type&& k, Args&&... args);               // C++17
// template <class... Args>
//  iterator try_emplace(const_iterator hint, const key_type& k, Args&&... args); // C++17
// template <class... Args>
//  iterator try_emplace(const_iterator hint, key_type&& k, Args&&... args);      // C++17

#include <unordered_map>
#include <cassert>
#include <iterator>
#include <tuple>

#include "test_macros.h"

class Moveable {
  Moveable(const Moveable&);
  Moveable& operator=(const Moveable&);

  int int_;
  double double_;

public:
  Moveable() : int_(0), double_(0) {}
  Moveable(int i, double d) : int_(i), double_(d) {}
  Moveable(Moveable&& x) : int_(x.int_), double_(x.double_) {
    x.int_    = -1;
    x.double_ = -1;
  }
  Moveable& operator=(Moveable&& x) {
    int_      = x.int_;
    x.int_    = -1;
    double_   = x.double_;
    x.double_ = -1;
    return *this;
  }

  bool operator==(const Moveable& x) const { return int_ == x.int_ && double_ == x.double_; }
  bool operator<(const Moveable& x) const { return int_ < x.int_ || (int_ == x.int_ && double_ < x.double_); }
  std::size_t hash() const { return std::hash<int>()(int_) + std::hash<double>()(double_); }

  int get() const { return int_; }
  bool moved() const { return int_ == -1; }
};

template <>
struct std::hash<Moveable> {
  std::size_t operator()(const Moveable& m) const { return m.hash(); }
};

int main(int, char**) {
  { // pair<iterator, bool> try_emplace(const key_type& k, Args&&... args);
    typedef std::unordered_map<int, Moveable> M;
    typedef std::pair<M::iterator, bool> R;
    M m;
    R r;
    for (int i = 0; i < 20; i += 2)
      m.emplace(i, Moveable(i, (double)i));
    assert(m.size() == 10);

    Moveable mv1(3, 3.0);
    for (int i = 0; i < 20; i += 2) {
      r = m.try_emplace(i, std::move(mv1));
      assert(m.size() == 10);
      assert(!r.second);           // was not inserted
      assert(!mv1.moved());        // was not moved from
      assert(r.first->first == i); // key
    }

    r = m.try_emplace(-1, std::move(mv1));
    assert(m.size() == 11);
    assert(r.second);                   // was inserted
    assert(mv1.moved());                // was moved from
    assert(r.first->first == -1);       // key
    assert(r.first->second.get() == 3); // value

    Moveable mv2(5, 3.0);
    r = m.try_emplace(5, std::move(mv2));
    assert(m.size() == 12);
    assert(r.second);                   // was inserted
    assert(mv2.moved());                // was moved from
    assert(r.first->first == 5);        // key
    assert(r.first->second.get() == 5); // value

    Moveable mv3(-1, 3.0);
    r = m.try_emplace(117, std::move(mv2));
    assert(m.size() == 13);
    assert(r.second);                    // was inserted
    assert(mv2.moved());                 // was moved from
    assert(r.first->first == 117);       // key
    assert(r.first->second.get() == -1); // value
  }

  { // pair<iterator, bool> try_emplace(key_type&& k, Args&&... args);
    typedef std::unordered_map<Moveable, Moveable> M;
    typedef std::pair<M::iterator, bool> R;
    M m;
    R r;
    for (int i = 0; i < 20; i += 2)
      m.emplace(Moveable(i, (double)i), Moveable(i + 1, (double)i + 1));
    assert(m.size() == 10);

    Moveable mvkey1(2, 2.0);
    Moveable mv1(4, 4.0);
    r = m.try_emplace(std::move(mvkey1), std::move(mv1));
    assert(m.size() == 10);
    assert(!r.second);                // was not inserted
    assert(!mv1.moved());             // was not moved from
    assert(!mvkey1.moved());          // was not moved from
    assert(r.first->first == mvkey1); // key

    Moveable mvkey2(3, 3.0);
    r = m.try_emplace(std::move(mvkey2), std::move(mv1));
    assert(m.size() == 11);
    assert(r.second);                   // was inserted
    assert(mv1.moved());                // was moved from
    assert(mvkey2.moved());             // was moved from
    assert(r.first->first.get() == 3);  // key
    assert(r.first->second.get() == 4); // value
  }

  { // iterator try_emplace(const_iterator hint, const key_type& k, Args&&... args);
    typedef std::unordered_map<int, Moveable> M;
    M m;
    M::iterator r;
    for (int i = 0; i < 20; i += 2)
      m.try_emplace(i, Moveable(i, (double)i));
    assert(m.size() == 10);
    M::const_iterator it = m.find(2);

    Moveable mv1(3, 3.0);
    for (int i = 0; i < 20; i += 2) {
      r = m.try_emplace(it, i, std::move(mv1));
      assert(m.size() == 10);
      assert(!mv1.moved());         // was not moved from
      assert(r->first == i);        // key
      assert(r->second.get() == i); // value
    }

    r = m.try_emplace(it, 3, std::move(mv1));
    assert(m.size() == 11);
    assert(mv1.moved());          // was moved from
    assert(r->first == 3);        // key
    assert(r->second.get() == 3); // value
  }

  { // iterator try_emplace(const_iterator hint, key_type&& k, Args&&... args);
    typedef std::unordered_map<Moveable, Moveable> M;
    M m;
    M::iterator r;
    for (int i = 0; i < 20; i += 2)
      m.emplace(Moveable(i, (double)i), Moveable(i + 1, (double)i + 1));
    assert(m.size() == 10);
    M::const_iterator it = std::next(m.cbegin());

    Moveable mvkey1(2, 2.0);
    Moveable mv1(4, 4.0);
    r = m.try_emplace(it, std::move(mvkey1), std::move(mv1));
    assert(m.size() == 10);
    assert(!mv1.moved());       // was not moved from
    assert(!mvkey1.moved());    // was not moved from
    assert(r->first == mvkey1); // key

    Moveable mvkey2(3, 3.0);
    r = m.try_emplace(it, std::move(mvkey2), std::move(mv1));
    assert(m.size() == 11);
    assert(mv1.moved());          // was moved from
    assert(mvkey2.moved());       // was moved from
    assert(r->first.get() == 3);  // key
    assert(r->second.get() == 4); // value
  }

  return 0;
}
