boost/smart_ptr/detail/atomic_count_std_atomic.hpp

#ifndef BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_STD_ATOMIC_HPP_INCLUDED
#define BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_STD_ATOMIC_HPP_INCLUDED
//
//  boost/detail/atomic_count_std_atomic.hpp
//
//  atomic_count for std::atomic
//
//  Copyright 2013 Peter Dimov
//
//  Distributed under the Boost Software License, Version 1.0.
//  See accompanying file LICENSE_1_0.txt or copy at
//  http://www.boost.org/LICENSE_1_0.txt
//
#include <atomic>
#include <cstdint>
namespace boost
{
namespace detail
{
class atomic_count
{
public:
    explicit atomic_count( long v ): value_( v )
    {
    }
    long operator++()
    {
        return value_.fetch_add( 1, std::memory_order_acq_rel ) + 1;
    }
    long operator--()
    {
        return value_.fetch_sub( 1, std::memory_order_acq_rel ) - 1;
    }
    operator long() const
    {
        return value_.load( std::memory_order_acquire );
    }
private:
    atomic_count(atomic_count const &);
    atomic_count & operator=(atomic_count const &);
    std::atomic_int_least32_t value_;
};
} // namespace detail
} // namespace boost
#endif // #ifndef BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_STD_ATOMIC_HPP_INCLUDED