ecency-mobile/ios/Pods/boost-for-react-native/boost/log/attributes/attribute_cast.hpp

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1.8 KiB
C++

/*
* Copyright Andrey Semashev 2007 - 2015.
* 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)
*/
/*!
* \file attribute_cast.hpp
* \author Andrey Semashev
* \date 06.08.2010
*
* The header contains utilities for casting between attribute factories.
*/
#ifndef BOOST_LOG_ATTRIBUTES_ATTRIBUTE_CAST_HPP_INCLUDED_
#define BOOST_LOG_ATTRIBUTES_ATTRIBUTE_CAST_HPP_INCLUDED_
#include <boost/log/detail/config.hpp>
#include <boost/log/attributes/attribute.hpp>
#include <boost/log/detail/header.hpp>
#ifdef BOOST_HAS_PRAGMA_ONCE
#pragma once
#endif
namespace boost {
BOOST_LOG_OPEN_NAMESPACE
namespace attributes {
/*!
* The class holds a reference to the attribute factory implementation being casted
*/
class cast_source
{
private:
attribute::impl* m_pImpl;
public:
/*!
* Initializing constructor. Creates a source that refers to the specified factory implementation.
*/
explicit cast_source(attribute::impl* p) : m_pImpl(p)
{
}
/*!
* The function attempts to cast the aggregated pointer to the implementation to the specified type.
*
* \return The converted pointer or \c NULL, if the conversion fails.
*/
template< typename T >
T* as() const { return dynamic_cast< T* >(m_pImpl); }
};
} // namespace attributes
/*!
* The function casts one attribute factory to another
*/
template< typename T >
inline T attribute_cast(attribute const& attr)
{
return T(attributes::cast_source(attr.get_impl()));
}
BOOST_LOG_CLOSE_NAMESPACE // namespace log
} // namespace boost
#include <boost/log/detail/footer.hpp>
#endif // BOOST_LOG_ATTRIBUTES_ATTRIBUTE_CAST_HPP_INCLUDED_