liuxiaolong
2021-07-20 58d904a328c0d849769b483e901a0be9426b8209
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
#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>
 
#if defined(BOOST_SP_REPORT_IMPLEMENTATION)
 
#include <boost/config/pragma_message.hpp>
BOOST_PRAGMA_MESSAGE("Using std::atomic atomic_count")
 
#endif
 
namespace boost
{
 
namespace detail
{
 
class atomic_count
{
public:
 
    explicit atomic_count( long v ): value_( static_cast< std::int_least32_t >( 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