libcxx/test/std/containers/container.adaptors/flat.multimap/flat.multimap.cons/default.pass.cpp

//===----------------------------------------------------------------------===//
//
// 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, c++17, c++20

// <flat_map>

// flat_multimap();

#include <cassert>
#include <deque>
#include <flat_map>
#include <functional>
#include <type_traits>
#include <vector>

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

struct DefaultCtableComp {
  explicit DefaultCtableComp() { default_constructed_ = true; }
  bool operator()(int, int) const { return false; }
  bool default_constructed_ = false;
};

int main(int, char**) {
  {
    std::flat_multimap<int, char*> m;
    assert(m.empty());
  }
  {
    // explicit(false)
    std::flat_multimap<int, char*> m = {};
    assert(m.empty());
  }
  {
    std::flat_multimap<int, char*, DefaultCtableComp, std::deque<int, min_allocator<int>>> m;
    assert(m.empty());
    assert(m.begin() == m.end());
    assert(m.key_comp().default_constructed_);
  }
  {
    using A1 = explicit_allocator<int>;
    using A2 = explicit_allocator<char*>;
    {
      std::flat_multimap<int, char*, DefaultCtableComp, std::vector<int, A1>, std::vector<char*, A2>> m;
      assert(m.empty());
      assert(m.key_comp().default_constructed_);
    }
    {
      A1 a1;
      std::flat_multimap<int, int, DefaultCtableComp, std::vector<int, A1>, std::vector<int, A1>> m(a1);
      assert(m.empty());
      assert(m.key_comp().default_constructed_);
    }
  }
  {
    // If an allocator is given, it must be usable by both containers.
    using A = test_allocator<int>;
    using M = std::flat_multimap<int, int, std::less<>, std::vector<int>, std::vector<int, A>>;
    static_assert(std::is_constructible_v<M>);
    static_assert(!std::is_constructible_v<M, std::allocator<int>>);
    static_assert(!std::is_constructible_v<M, A>);
  }
  return 0;
}