Chris@16: /*
Chris@101:  *          Copyright Andrey Semashev 2007 - 2015.
Chris@16:  * Distributed under the Boost Software License, Version 1.0.
Chris@16:  *    (See accompanying file LICENSE_1_0.txt or copy at
Chris@16:  *          http://www.boost.org/LICENSE_1_0.txt)
Chris@16:  */
Chris@16: /*!
Chris@16:  * \file   attribute_value_impl.hpp
Chris@16:  * \author Andrey Semashev
Chris@16:  * \date   24.06.2007
Chris@16:  *
Chris@16:  * The header contains an implementation of a basic attribute value implementation class.
Chris@16:  */
Chris@16: 
Chris@16: #ifndef BOOST_LOG_ATTRIBUTES_ATTRIBUTE_VALUE_IMPL_HPP_INCLUDED_
Chris@16: #define BOOST_LOG_ATTRIBUTES_ATTRIBUTE_VALUE_IMPL_HPP_INCLUDED_
Chris@16: 
Chris@16: #include <boost/move/core.hpp>
Chris@16: #include <boost/move/utility.hpp>
Chris@16: #include <boost/type_traits/remove_cv.hpp>
Chris@16: #include <boost/log/detail/config.hpp>
Chris@16: #include <boost/log/attributes/attribute_value.hpp>
Chris@16: #include <boost/log/utility/type_dispatch/type_dispatcher.hpp>
Chris@16: #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
Chris@16: #include <boost/type_traits/remove_reference.hpp>
Chris@16: #endif
Chris@16: #include <boost/log/detail/header.hpp>
Chris@16: 
Chris@16: #ifdef BOOST_HAS_PRAGMA_ONCE
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: BOOST_LOG_OPEN_NAMESPACE
Chris@16: 
Chris@16: namespace attributes {
Chris@16: 
Chris@16: /*!
Chris@16:  * \brief Basic attribute value implementation class
Chris@16:  *
Chris@16:  * This class can be used as a boilerplate for simple attribute values. The class implements all needed
Chris@16:  * interfaces of attribute values and allows to store a single value of the type specified as a template parameter.
Chris@16:  * The stored value can be dispatched with type dispatching mechanism.
Chris@16:  */
Chris@16: template< typename T >
Chris@16: class attribute_value_impl :
Chris@16:     public attribute_value::impl
Chris@16: {
Chris@16: public:
Chris@16:     //! Value type
Chris@16:     typedef T value_type;
Chris@16: 
Chris@16: private:
Chris@16:     //! Attribute value
Chris@16:     const value_type m_value;
Chris@16: 
Chris@16: public:
Chris@16:     /*!
Chris@16:      * Constructor with initialization of the stored value
Chris@16:      */
Chris@16:     explicit attribute_value_impl(value_type const& v) : m_value(v) {}
Chris@16:     /*!
Chris@16:      * Constructor with initialization of the stored value
Chris@16:      */
Chris@16:     explicit attribute_value_impl(BOOST_RV_REF(value_type) v) : m_value(v) {}
Chris@16: 
Chris@16:     /*!
Chris@16:      * Attribute value dispatching method.
Chris@16:      *
Chris@16:      * \param dispatcher The dispatcher that receives the stored value
Chris@16:      *
Chris@16:      * \return \c true if the value has been dispatched, \c false otherwise
Chris@16:      */
Chris@16:     virtual bool dispatch(type_dispatcher& dispatcher)
Chris@16:     {
Chris@16:         type_dispatcher::callback< value_type > callback = dispatcher.get_callback< value_type >();
Chris@16:         if (callback)
Chris@16:         {
Chris@16:             callback(m_value);
Chris@16:             return true;
Chris@16:         }
Chris@16:         else
Chris@16:             return false;
Chris@16:     }
Chris@16: 
Chris@16:     /*!
Chris@16:      * \return The attribute value type
Chris@16:      */
Chris@16:     type_info_wrapper get_type() const { return type_info_wrapper(typeid(value_type)); }
Chris@16: 
Chris@16:     /*!
Chris@16:      * \return Reference to the contained value.
Chris@16:      */
Chris@16:     value_type const& get() const { return m_value; }
Chris@16: };
Chris@16: 
Chris@16: /*!
Chris@16:  * The function creates an attribute value from the specified object.
Chris@16:  */
Chris@16: #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
Chris@16: 
Chris@16: template< typename T >
Chris@16: inline attribute_value make_attribute_value(T&& v)
Chris@16: {
Chris@16:     typedef typename remove_cv< typename remove_reference< T >::type >::type value_type;
Chris@16:     return attribute_value(new attribute_value_impl< value_type >(boost::forward< T >(v)));
Chris@16: }
Chris@16: 
Chris@16: #else // !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
Chris@16: 
Chris@16: template< typename T >
Chris@16: inline attribute_value make_attribute_value(T const& v)
Chris@16: {
Chris@16:     typedef typename remove_cv< T >::type value_type;
Chris@16:     return attribute_value(new attribute_value_impl< value_type >(v));
Chris@16: }
Chris@16: 
Chris@16: template< typename T >
Chris@16: inline attribute_value make_attribute_value(rv< T > const& v)
Chris@16: {
Chris@16:     typedef typename remove_cv< T >::type value_type;
Chris@16:     return attribute_value(new attribute_value_impl< value_type >(v));
Chris@16: }
Chris@16: 
Chris@16: #endif // !defined(BOOST_NO_CXX11_RVALUE_REFERENCES)
Chris@16: 
Chris@16: } // namespace attributes
Chris@16: 
Chris@16: BOOST_LOG_CLOSE_NAMESPACE // namespace log
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #include <boost/log/detail/footer.hpp>
Chris@16: 
Chris@16: #endif // BOOST_LOG_ATTRIBUTES_ATTRIBUTE_VALUE_IMPL_HPP_INCLUDED_