static_object.hpp
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/*
Copyright (c) 2014, Randolph Voorhies, Shane Grant
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
* Neither the name of cereal nor the
names of its contributors may be used to endorse or promote products
derived from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL RANDOLPH VOORHIES OR SHANE GRANT BE LIABLE FOR ANY
DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef CEREAL_DETAILS_STATIC_OBJECT_HPP_
#define CEREAL_DETAILS_STATIC_OBJECT_HPP_
#include "cereal/macros.hpp"
#if CEREAL_THREAD_SAFE
#include <mutex>
#endif
#ifdef _MSC_VER
# define CEREAL_DLL_EXPORT __declspec(dllexport)
# define CEREAL_USED
#else // clang or gcc
# define CEREAL_DLL_EXPORT __attribute__ ((visibility("default")))
# define CEREAL_USED __attribute__ ((__used__))
#endif
namespace cereal
{
namespace detail
{
template <class T>
class CEREAL_DLL_EXPORT StaticObject
{
private:
static T & create()
{
static T t;
(void)instance;
return t;
}
StaticObject( StaticObject const & /*other*/ ) {}
public:
static T & getInstance()
{
return create();
}
class LockGuard
{
#if CEREAL_THREAD_SAFE
public:
LockGuard(std::mutex & m) : lock(m) {}
private:
std::unique_lock<std::mutex> lock;
#else
public:
LockGuard(LockGuard const &) = default; // prevents implicit copy ctor warning
~LockGuard() CEREAL_NOEXCEPT {} // prevents variable not used
#endif
};
static LockGuard lock()
{
#if CEREAL_THREAD_SAFE
static std::mutex instanceMutex;
return LockGuard{instanceMutex};
#else
return LockGuard{};
#endif
}
private:
static T & instance;
};
template <class T> T & StaticObject<T>::instance = StaticObject<T>::create();
} // namespace detail
} // namespace cereal
#endif // CEREAL_DETAILS_STATIC_OBJECT_HPP_
cereal::detail::StaticObject::lock
static LockGuard lock()
Attempts to lock this static object for the current scope.
Definition: static_object.hpp:109
cereal
Definition: access.hpp:41
macros.hpp
Preprocessor macros that can customise the cereal library.
CEREAL_NOEXCEPT
#define CEREAL_NOEXCEPT
Defines the CEREAL_NOEXCEPT macro to use instead of noexcept.
Definition: macros.hpp:130
CEREAL_DLL_EXPORT
#define CEREAL_DLL_EXPORT
Prevent link optimization from removing non-referenced static objects.
Definition: static_object.hpp:51
cereal::detail::StaticObject
A static, pre-execution object.
Definition: static_object.hpp:67
cereal::detail::StaticObject::LockGuard
A class that acts like std::lock_guard.
Definition: static_object.hpp:88