ceph/src/boost/boost/log/detail/attribute_predicate.hpp

   1 /*
   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)
   6  */
   7 /*!
   8  * \file   attribute_predicate.hpp
   9  * \author Andrey Semashev
  10  * \date   02.09.2012
  11  *
  12  * The header contains implementation of a generic predicate in template expressions.
  13  */
  14
  15 #ifndef BOOST_LOG_DETAIL_ATTRIBUTE_PREDICATE_HPP_INCLUDED_
  16 #define BOOST_LOG_DETAIL_ATTRIBUTE_PREDICATE_HPP_INCLUDED_
  17
  18 #include <boost/phoenix/core/actor.hpp>
  19 #include <boost/utility/result_of.hpp>
  20 #include <boost/log/detail/config.hpp>
  21 #include <boost/log/attributes/attribute_name.hpp>
  22 #include <boost/log/attributes/value_visitation.hpp>
  23 #include <boost/log/attributes/fallback_policy.hpp>
  24 #include <boost/log/utility/functional/bind.hpp>
  25 #include <boost/log/utility/functional/save_result.hpp>
  26 #include <boost/log/detail/header.hpp>
  27
  28 #ifdef BOOST_HAS_PRAGMA_ONCE
  29 #pragma once
  30 #endif
  31
  32 namespace boost {
  33
  34 BOOST_LOG_OPEN_NAMESPACE
  35
  36 namespace expressions {
  37
  38 namespace aux {
  39
  40 /*!
  41  * The predicate checks if the attribute value satisfies a predicate.
  42  */
  43 template< typename T, typename ArgT, typename PredicateT, typename FallbackPolicyT = fallback_to_none >
  44 class attribute_predicate
  45 {
  46 public:
  47     //! Function result_type
  48     typedef bool result_type;
  49     //! Expected attribute value type
  50     typedef T value_type;
  51     //! Predicate type
  52     typedef PredicateT predicate_type;
  53     //! Argument type for the predicate
  54     typedef ArgT argument_type;
  55     //! Fallback policy
  56     typedef FallbackPolicyT fallback_policy;
  57
  58 private:
  59     //! Argument for the predicate
  60     const argument_type m_arg;
  61     //! Attribute value name
  62     const attribute_name m_name;
  63     //! Visitor invoker
  64     value_visitor_invoker< value_type, fallback_policy > m_visitor_invoker;
  65
  66 public:
  67     /*!
  68      * Initializing constructor
  69      *
  70      * \param name Attribute name
  71      * \param pred_arg The predicate argument
  72      */
  73     attribute_predicate(attribute_name const& name, argument_type const& pred_arg) : m_arg(pred_arg), m_name(name)
  74     {
  75     }
  76
  77     /*!
  78      * Initializing constructor
  79      *
  80      * \param name Attribute name
  81      * \param pred_arg The predicate argument
  82      * \param arg Additional parameter for the fallback policy
  83      */
  84     template< typename U >
  85     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)
  86     {
  87     }
  88
  89     /*!
  90      * Checking operator
  91      *
  92      * \param arg A set of attribute values or a log record
  93      * \return \c true if the log record contains the sought attribute value, \c false otherwise
  94      */
  95     template< typename ArgumentT >
  96     result_type operator() (ArgumentT const& arg) const
  97     {
  98         typedef binder2nd< predicate_type, argument_type const& > visitor_type;
  99
 100         bool res = false;
 101         m_visitor_invoker(m_name, arg, boost::log::save_result(visitor_type(predicate_type(), m_arg), res));
 102         return res;
 103     }
 104 };
 105
 106 } // namespace aux
 107
 108 } // namespace expressions
 109
 110 BOOST_LOG_CLOSE_NAMESPACE // namespace log
 111
 112 } // namespace boost
 113
 114 #include <boost/log/detail/footer.hpp>
 115
 116 #endif // BOOST_LOG_DETAIL_ATTRIBUTE_PREDICATE_HPP_INCLUDED_