ceph/src/boost/libs/log/include/boost/log/sources/features.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   sources/features.hpp
   9  * \author Andrey Semashev
  10  * \date   17.07.2009
  11  *
  12  * The header contains definition of a features list class template.
  13  */
  14
  15 #ifndef BOOST_LOG_SOURCES_FEATURES_HPP_INCLUDED_
  16 #define BOOST_LOG_SOURCES_FEATURES_HPP_INCLUDED_
  17
  18 #include <boost/mpl/lambda.hpp>
  19 #include <boost/log/detail/config.hpp>
  20
  21 #ifdef BOOST_HAS_PRAGMA_ONCE
  22 #pragma once
  23 #endif
  24
  25 #if defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
  26
  27 #include <boost/preprocessor/repetition/enum_params.hpp>
  28 #include <boost/preprocessor/repetition/enum_binary_params.hpp>
  29 #include <boost/preprocessor/repetition/enum_shifted_params.hpp>
  30 #include <boost/preprocessor/facilities/intercept.hpp>
  31
  32 //! The macro defines the maximum number of features that can be specified for a logger
  33 #ifndef BOOST_LOG_FEATURES_LIMIT
  34 #define BOOST_LOG_FEATURES_LIMIT 10
  35 #endif // BOOST_LOG_FEATURES_LIMIT
  36
  37 #endif
  38
  39 #include <boost/log/detail/header.hpp>
  40
  41 namespace boost {
  42
  43 BOOST_LOG_OPEN_NAMESPACE
  44
  45 namespace sources {
  46
  47 #if defined(BOOST_LOG_DOXYGEN_PASS) || !defined(BOOST_NO_CXX11_VARIADIC_TEMPLATES)
  48
  49 /*!
  50  * \brief A type sequence of logger features
  51  *
  52  * This class template can be used to specify logger features in a \c basic_composite_logger instantiation.
  53  */
  54 template< typename... FeaturesT >
  55 struct features
  56 {
  57 };
  58
  59 namespace aux {
  60
  61 //! The metafunction produces the inherited features hierarchy with \c RootT as the ultimate base type
  62 template< typename RootT, typename FeaturesT >
  63 struct inherit_features;
  64
  65 template< typename RootT, typename FeatureT0, typename... FeaturesT >
  66 struct inherit_features< RootT, features< FeatureT0, FeaturesT... > >
  67 {
  68     typedef typename mpl::lambda<
  69         FeatureT0
  70     >::type::BOOST_NESTED_TEMPLATE apply<
  71         typename inherit_features<
  72             RootT,
  73             features< FeaturesT... >
  74         >::type
  75     >::type type;
  76 };
  77
  78 template< typename RootT, typename FeatureT0 >
  79 struct inherit_features< RootT, features< FeatureT0 > >
  80 {
  81     typedef typename mpl::lambda<
  82         FeatureT0
  83     >::type::BOOST_NESTED_TEMPLATE apply<
  84         RootT
  85     >::type type;
  86 };
  87
  88 template< typename RootT >
  89 struct inherit_features< RootT, features< > >
  90 {
  91     typedef RootT type;
  92 };
  93
  94 } // namespace aux
  95
  96 #else
  97
  98 //! A type sequence of logger features
  99 template< BOOST_PP_ENUM_BINARY_PARAMS(BOOST_LOG_FEATURES_LIMIT, typename FeatureT, = void BOOST_PP_INTERCEPT) >
 100 struct features
 101 {
 102 };
 103
 104 namespace aux {
 105
 106 template< typename RootT, typename FeaturesT >
 107 struct inherit_features;
 108
 109 template< typename RootT, BOOST_PP_ENUM_PARAMS(BOOST_LOG_FEATURES_LIMIT, typename FeatureT) >
 110 struct inherit_features< RootT, features< BOOST_PP_ENUM_PARAMS(BOOST_LOG_FEATURES_LIMIT, FeatureT) > >
 111 {
 112     typedef typename mpl::lambda<
 113         FeatureT0
 114     >::type::BOOST_NESTED_TEMPLATE apply<
 115         typename inherit_features<
 116             RootT,
 117             features< BOOST_PP_ENUM_SHIFTED_PARAMS(BOOST_LOG_FEATURES_LIMIT, FeatureT) >
 118         >::type
 119     >::type type;
 120 };
 121
 122 template< typename RootT, typename FeatureT0 >
 123 struct inherit_features< RootT, features< FeatureT0, BOOST_PP_ENUM_SHIFTED_PARAMS(BOOST_LOG_FEATURES_LIMIT, void BOOST_PP_INTERCEPT) > >
 124 {
 125     typedef typename mpl::lambda<
 126         FeatureT0
 127     >::type::BOOST_NESTED_TEMPLATE apply<
 128         RootT
 129     >::type type;
 130 };
 131
 132 template< typename RootT >
 133 struct inherit_features< RootT, features< BOOST_PP_ENUM_PARAMS(BOOST_LOG_FEATURES_LIMIT, void BOOST_PP_INTERCEPT) > >
 134 {
 135     typedef RootT type;
 136 };
 137
 138 } // namespace aux
 139
 140 #endif
 141
 142 } // namespace sources
 143
 144 BOOST_LOG_CLOSE_NAMESPACE // namespace log
 145
 146 } // namespace boost
 147
 148 #include <boost/log/detail/footer.hpp>
 149
 150 #endif // BOOST_LOG_SOURCES_FEATURES_HPP_INCLUDED_