2 * Copyright Andrey Semashev 2007 - 2015.
3 * Distributed under the Boost Software License, Version 1.0.
4 * (See accompanying file LICENSE_1_0.txt or copy at
5 * http://www.boost.org/LICENSE_1_0.txt)
8 * \file attribute_cast.hpp
9 * \author Andrey Semashev
12 * The header contains utilities for casting between attribute factories.
15 #ifndef BOOST_LOG_ATTRIBUTES_ATTRIBUTE_CAST_HPP_INCLUDED_
16 #define BOOST_LOG_ATTRIBUTES_ATTRIBUTE_CAST_HPP_INCLUDED_
18 #include <boost/log/detail/config.hpp>
19 #include <boost/log/attributes/attribute.hpp>
20 #include <boost/log/detail/header.hpp>
22 #ifdef BOOST_HAS_PRAGMA_ONCE
28 BOOST_LOG_OPEN_NAMESPACE
30 namespace attributes {
33 * The class holds a reference to the attribute factory implementation being casted
38 attribute::impl* m_pImpl;
42 * Initializing constructor. Creates a source that refers to the specified factory implementation.
44 explicit cast_source(attribute::impl* p) : m_pImpl(p)
49 * The function attempts to cast the aggregated pointer to the implementation to the specified type.
51 * \return The converted pointer or \c NULL, if the conversion fails.
53 template< typename T >
54 T* as() const { return dynamic_cast< T* >(m_pImpl); }
57 } // namespace attributes
60 * The function casts one attribute factory to another
62 template< typename T >
63 inline T attribute_cast(attribute const& attr)
65 return T(attributes::cast_source(attr.get_impl()));
68 BOOST_LOG_CLOSE_NAMESPACE // namespace log
72 #include <boost/log/detail/footer.hpp>
74 #endif // BOOST_LOG_ATTRIBUTES_ATTRIBUTE_CAST_HPP_INCLUDED_