libcxx/test/std/utilities/memory/specialized.algorithms/specialized.destroy/destroy_n.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++98, c++03, c++11, c++14

// <memory>

// template <class ForwardIt, class Size>
// ForwardIt destroy_n(ForwardIt, Size s);

#include <memory>
#include <cstdlib>
#include <cassert>

#include "test_macros.h"
#include "test_iterators.h"

struct Counted {
  static int count;
  static void reset() { count = 0; }
  Counted() { ++count; }
  Counted(Counted const&) { ++count; }
  ~Counted() { --count; }
  friend void operator&(Counted) = delete;
};
int Counted::count = 0;

int main(int, char**)
{
    using It = forward_iterator<Counted*>;
    const int N = 5;
    alignas(Counted) char pool[sizeof(Counted)*N] = {};
    Counted* p = (Counted*)pool;
    std::uninitialized_fill(p, p+N, Counted());
    assert(Counted::count == 5);
    Counted* np = std::destroy_n(p, 1);
    assert(np == p+1);
    assert(Counted::count == 4);
    p += 1;
    It it = std::destroy_n(It(p), 4);
    assert(it == It(p+4));
    assert(Counted::count == 0);

  return 0;
}