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_predicate.hpp
Chris@16:  * \author Andrey Semashev
Chris@16:  * \date   02.09.2012
Chris@16:  *
Chris@16:  * The header contains implementation of a generic predicate in template expressions.
Chris@16:  */
Chris@16: 
Chris@16: #ifndef BOOST_LOG_DETAIL_ATTRIBUTE_PREDICATE_HPP_INCLUDED_
Chris@16: #define BOOST_LOG_DETAIL_ATTRIBUTE_PREDICATE_HPP_INCLUDED_
Chris@16: 
Chris@16: #include <boost/phoenix/core/actor.hpp>
Chris@16: #include <boost/utility/result_of.hpp>
Chris@16: #include <boost/log/detail/config.hpp>
Chris@16: #include <boost/log/attributes/attribute_name.hpp>
Chris@16: #include <boost/log/attributes/value_visitation.hpp>
Chris@16: #include <boost/log/attributes/fallback_policy.hpp>
Chris@16: #include <boost/log/utility/functional/bind.hpp>
Chris@16: #include <boost/log/utility/functional/save_result.hpp>
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 expressions {
Chris@16: 
Chris@16: namespace aux {
Chris@16: 
Chris@16: /*!
Chris@16:  * The predicate checks if the attribute value satisfies a predicate.
Chris@16:  */
Chris@16: template< typename T, typename ArgT, typename PredicateT, typename FallbackPolicyT = fallback_to_none >
Chris@16: class attribute_predicate
Chris@16: {
Chris@16: public:
Chris@16:     //! Function result_type
Chris@16:     typedef bool result_type;
Chris@16:     //! Expected attribute value type
Chris@16:     typedef T value_type;
Chris@16:     //! Predicate type
Chris@16:     typedef PredicateT predicate_type;
Chris@16:     //! Argument type for the predicate
Chris@16:     typedef ArgT argument_type;
Chris@16:     //! Fallback policy
Chris@16:     typedef FallbackPolicyT fallback_policy;
Chris@16: 
Chris@16: private:
Chris@16:     //! Argument for the predicate
Chris@16:     const argument_type m_arg;
Chris@16:     //! Attribute value name
Chris@16:     const attribute_name m_name;
Chris@16:     //! Visitor invoker
Chris@16:     value_visitor_invoker< value_type, fallback_policy > m_visitor_invoker;
Chris@16: 
Chris@16: public:
Chris@16:     /*!
Chris@16:      * Initializing constructor
Chris@16:      *
Chris@16:      * \param name Attribute name
Chris@16:      * \param pred_arg The predicate argument
Chris@16:      */
Chris@16:     attribute_predicate(attribute_name const& name, argument_type const& pred_arg) : m_arg(pred_arg), m_name(name)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     /*!
Chris@16:      * Initializing constructor
Chris@16:      *
Chris@16:      * \param name Attribute name
Chris@16:      * \param pred_arg The predicate argument
Chris@16:      * \param arg Additional parameter for the fallback policy
Chris@16:      */
Chris@16:     template< typename U >
Chris@16:     attribute_predicate(attribute_name const& name, argument_type const& pred_arg, U const& arg) : m_arg(pred_arg), m_name(name), m_visitor_invoker(arg)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     /*!
Chris@16:      * Checking operator
Chris@16:      *
Chris@16:      * \param arg A set of attribute values or a log record
Chris@16:      * \return \c true if the log record contains the sought attribute value, \c false otherwise
Chris@16:      */
Chris@16:     template< typename ArgumentT >
Chris@16:     result_type operator() (ArgumentT const& arg) const
Chris@16:     {
Chris@16:         typedef binder2nd< predicate_type, argument_type const& > visitor_type;
Chris@16: 
Chris@16:         bool res = false;
Chris@16:         m_visitor_invoker(m_name, arg, boost::log::save_result(visitor_type(predicate_type(), m_arg), res));
Chris@16:         return res;
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: } // namespace aux
Chris@16: 
Chris@16: } // namespace expressions
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_DETAIL_ATTRIBUTE_PREDICATE_HPP_INCLUDED_