mirror of
https://github.com/matrix-construct/construct
synced 2024-12-11 08:02:59 +01:00
37 lines
935 B
C++
37 lines
935 B
C++
// The Construct
|
|
//
|
|
// Copyright (C) The Construct Developers, Authors & Contributors
|
|
// Copyright (C) 2016-2020 Jason Volk <jason@zemos.net>
|
|
//
|
|
// Permission to use, copy, modify, and/or distribute this software for any
|
|
// purpose with or without fee is hereby granted, provided that the above
|
|
// copyright notice and this permission notice is present in all copies. The
|
|
// full license for this software is available in the LICENSE file.
|
|
|
|
#pragma once
|
|
#define HAVE_IRCD_UTIL_COMPARE_EXCHANGE_H
|
|
|
|
namespace ircd {
|
|
inline namespace util
|
|
{
|
|
template<class T>
|
|
bool compare_exchange(T &value, T &expect, T desire) noexcept;
|
|
}}
|
|
|
|
/// Non-atomic compare_exchange().
|
|
template<class T>
|
|
inline bool
|
|
ircd::util::compare_exchange(T &value,
|
|
T &expect,
|
|
T desire)
|
|
noexcept
|
|
{
|
|
const bool ret
|
|
{
|
|
value == expect
|
|
};
|
|
|
|
value = ret? desire: value;
|
|
expect = ret? expect: value;
|
|
return ret;
|
|
}
|