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   formatters/if.hpp
Chris@16:  * \author Andrey Semashev
Chris@16:  * \date   17.11.2012
Chris@16:  *
Chris@16:  * The header contains implementation of a conditional formatter.
Chris@16:  */
Chris@16: 
Chris@16: #ifndef BOOST_LOG_EXPRESSIONS_FORMATTERS_IF_HPP_INCLUDED_
Chris@16: #define BOOST_LOG_EXPRESSIONS_FORMATTERS_IF_HPP_INCLUDED_
Chris@16: 
Chris@16: #include <boost/mpl/bool.hpp>
Chris@16: #include <boost/phoenix/core/actor.hpp>
Chris@16: #include <boost/phoenix/core/meta_grammar.hpp>
Chris@16: #include <boost/phoenix/core/terminal_fwd.hpp>
Chris@16: #include <boost/phoenix/core/is_nullary.hpp>
Chris@16: #include <boost/phoenix/core/environment.hpp>
Chris@16: #include <boost/fusion/sequence/intrinsic/at_c.hpp>
Chris@16: #include <boost/type_traits/remove_cv.hpp>
Chris@16: #include <boost/type_traits/remove_reference.hpp>
Chris@16: #include <boost/log/detail/config.hpp>
Chris@16: #include <boost/log/detail/custom_terminal_spec.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: template< typename LeftT, typename CondT, typename ThenT >
Chris@16: class if_output_terminal
Chris@16: {
Chris@16: private:
Chris@16:     //! Self type
Chris@16:     typedef if_output_terminal this_type;
Chris@16: 
Chris@16: public:
Chris@16:     //! Internal typedef for type categorization
Chris@16:     typedef void _is_boost_log_terminal;
Chris@16: 
Chris@16:     //! Result type definition
Chris@16:     template< typename >
Chris@16:     struct result;
Chris@16: 
Chris@101:     template< typename ThisT, typename ContextT >
Chris@101:     struct result< ThisT(ContextT) >
Chris@16:     {
Chris@16:         typedef typename remove_cv< typename remove_reference< ContextT >::type >::type context_type;
Chris@16:         typedef typename phoenix::evaluator::impl<
Chris@16:             typename LeftT::proto_base_expr&,
Chris@16:             context_type,
Chris@16:             phoenix::unused
Chris@16:         >::result_type type;
Chris@16:     };
Chris@16: 
Chris@16: private:
Chris@16:     //! Left argument actor
Chris@16:     LeftT m_left;
Chris@16:     //! Condition expression
Chris@16:     CondT m_cond;
Chris@16:     //! Positive branch
Chris@16:     ThenT m_then;
Chris@16: 
Chris@16: public:
Chris@16:     //! Initializing constructor
Chris@16:     if_output_terminal(LeftT const& left, CondT const& cond, ThenT const& then_) : m_left(left), m_cond(cond), m_then(then_)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     //! Invokation operator
Chris@16:     template< typename ContextT >
Chris@16:     typename result< this_type(ContextT const&) >::type operator() (ContextT const& ctx)
Chris@16:     {
Chris@16:         typedef typename result< this_type(ContextT const&) >::type result_type;
Chris@16:         result_type strm = phoenix::eval(m_left, ctx);
Chris@16:         if (phoenix::eval(m_cond, ctx))
Chris@16:             phoenix::eval(m_then, ctx);
Chris@16:         return strm;
Chris@16:     }
Chris@16: 
Chris@16:     //! Invokation operator
Chris@16:     template< typename ContextT >
Chris@16:     typename result< const this_type(ContextT const&) >::type operator() (ContextT const& ctx) const
Chris@16:     {
Chris@16:         typedef typename result< const this_type(ContextT const&) >::type result_type;
Chris@16:         result_type strm = phoenix::eval(m_left, ctx);
Chris@16:         if (phoenix::eval(m_cond, ctx))
Chris@16:             phoenix::eval(m_then, ctx);
Chris@16:         return strm;
Chris@16:     }
Chris@16: 
Chris@16:     BOOST_DELETED_FUNCTION(if_output_terminal())
Chris@16: };
Chris@16: 
Chris@16: template< typename LeftT, typename CondT, typename ThenT, typename ElseT >
Chris@16: class if_else_output_terminal
Chris@16: {
Chris@16: private:
Chris@16:     //! Self type
Chris@16:     typedef if_else_output_terminal this_type;
Chris@16: 
Chris@16: public:
Chris@16:     //! Internal typedef for type categorization
Chris@16:     typedef void _is_boost_log_terminal;
Chris@16: 
Chris@16:     //! Result type definition
Chris@16:     template< typename >
Chris@16:     struct result;
Chris@16: 
Chris@101:     template< typename ThisT, typename ContextT >
Chris@101:     struct result< ThisT(ContextT) >
Chris@16:     {
Chris@16:         typedef typename remove_cv< typename remove_reference< ContextT >::type >::type context_type;
Chris@16:         typedef typename phoenix::evaluator::impl<
Chris@16:             typename LeftT::proto_base_expr&,
Chris@16:             context_type,
Chris@16:             phoenix::unused
Chris@16:         >::result_type type;
Chris@16:     };
Chris@16: 
Chris@16: private:
Chris@16:     //! Left argument actor
Chris@16:     LeftT m_left;
Chris@16:     //! Condition expression
Chris@16:     CondT m_cond;
Chris@16:     //! Positive branch
Chris@16:     ThenT m_then;
Chris@16:     //! Negative branch
Chris@16:     ElseT m_else;
Chris@16: 
Chris@16: public:
Chris@16:     //! Initializing constructor
Chris@16:     if_else_output_terminal(LeftT const& left, CondT const& cond, ThenT const& then_, ElseT const& else_) : m_left(left), m_cond(cond), m_then(then_), m_else(else_)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     //! Invokation operator
Chris@16:     template< typename ContextT >
Chris@16:     typename result< this_type(ContextT const&) >::type operator() (ContextT const& ctx)
Chris@16:     {
Chris@16:         typedef typename result< this_type(ContextT const&) >::type result_type;
Chris@16:         result_type strm = phoenix::eval(m_left, ctx);
Chris@16:         if (phoenix::eval(m_cond, ctx))
Chris@16:             phoenix::eval(m_then, ctx);
Chris@16:         else
Chris@16:             phoenix::eval(m_else, ctx);
Chris@16:         return strm;
Chris@16:     }
Chris@16: 
Chris@16:     //! Invokation operator
Chris@16:     template< typename ContextT >
Chris@16:     typename result< const this_type(ContextT const&) >::type operator() (ContextT const& ctx) const
Chris@16:     {
Chris@16:         typedef typename result< const this_type(ContextT const&) >::type result_type;
Chris@16:         result_type strm = phoenix::eval(m_left, ctx);
Chris@16:         if (phoenix::eval(m_cond, ctx))
Chris@16:             phoenix::eval(m_then, ctx);
Chris@16:         else
Chris@16:             phoenix::eval(m_else, ctx);
Chris@16:         return strm;
Chris@16:     }
Chris@16: 
Chris@16:     BOOST_DELETED_FUNCTION(if_else_output_terminal())
Chris@16: };
Chris@16: 
Chris@16: 
Chris@16: template< typename CondT, typename ThenT, typename ElseT >
Chris@16: struct if_then_else_gen
Chris@16: {
Chris@16:     CondT m_cond;
Chris@16:     ThenT m_then;
Chris@16:     ElseT m_else;
Chris@16: 
Chris@16:     if_then_else_gen(CondT const& cond, ThenT const& then_, ElseT const& else_) : m_cond(cond), m_then(then_), m_else(else_)
Chris@16:     {
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: #ifndef BOOST_LOG_DOXYGEN_PASS
Chris@16: 
Chris@16: #define BOOST_LOG_AUX_OVERLOAD(left_ref, right_ref)\
Chris@16:     template< typename LeftExprT, typename CondT, typename ThenT, typename ElseT >\
Chris@16:     BOOST_FORCEINLINE phoenix::actor< if_else_output_terminal< phoenix::actor< LeftExprT >, CondT, ThenT, ElseT > >\
Chris@16:     operator<< (phoenix::actor< LeftExprT > left_ref left, if_then_else_gen< CondT, ThenT, ElseT > right_ref right)\
Chris@16:     {\
Chris@16:         typedef if_else_output_terminal< phoenix::actor< LeftExprT >, CondT, ThenT, ElseT > terminal_type;\
Chris@16:         phoenix::actor< terminal_type > actor = {{ terminal_type(left, right.m_cond, right.m_then, right.m_else) }};\
Chris@16:         return actor;\
Chris@16:     }
Chris@16: 
Chris@16: #include <boost/log/detail/generate_overloads.hpp>
Chris@16: 
Chris@16: #undef BOOST_LOG_AUX_OVERLOAD
Chris@16: 
Chris@16: #endif // BOOST_LOG_DOXYGEN_PASS
Chris@16: 
Chris@16: template< typename CondT, typename ThenT >
Chris@16: struct if_then_gen
Chris@16: {
Chris@16:     struct else_gen
Chris@16:     {
Chris@16:         CondT m_cond;
Chris@16:         ThenT m_then;
Chris@16: 
Chris@16:         else_gen(CondT const& cond, ThenT const& then_) : m_cond(cond), m_then(then_)
Chris@16:         {
Chris@16:         }
Chris@16: 
Chris@16:         template< typename ElseT >
Chris@16:         BOOST_FORCEINLINE if_then_else_gen< CondT, ThenT, ElseT > operator[] (ElseT const& el)
Chris@16:         {
Chris@16:             return if_then_else_gen< CondT, ThenT, ElseT >(m_cond, m_then, el);
Chris@16:         }
Chris@16:     }
Chris@16:     else_;
Chris@16: 
Chris@16:     if_then_gen(CondT const& cond, ThenT const& then_) : else_(cond, then_) {}
Chris@16: };
Chris@16: 
Chris@16: #ifndef BOOST_LOG_DOXYGEN_PASS
Chris@16: 
Chris@16: #define BOOST_LOG_AUX_OVERLOAD(left_ref, right_ref)\
Chris@16:     template< typename LeftExprT, typename CondT, typename ThenT >\
Chris@16:     BOOST_FORCEINLINE phoenix::actor< if_output_terminal< phoenix::actor< LeftExprT >, CondT, ThenT > >\
Chris@16:     operator<< (phoenix::actor< LeftExprT > left_ref left, if_then_gen< CondT, ThenT > right_ref right)\
Chris@16:     {\
Chris@16:         typedef if_output_terminal< phoenix::actor< LeftExprT >, CondT, ThenT > terminal_type;\
Chris@16:         phoenix::actor< terminal_type > actor = {{ terminal_type(left, right.else_.m_cond, right.else_.m_then) }};\
Chris@16:         return actor;\
Chris@16:     }
Chris@16: 
Chris@16: #include <boost/log/detail/generate_overloads.hpp>
Chris@16: 
Chris@16: #undef BOOST_LOG_AUX_OVERLOAD
Chris@16: 
Chris@16: #endif // BOOST_LOG_DOXYGEN_PASS
Chris@16: 
Chris@16: template< typename CondT >
Chris@16: class if_gen
Chris@16: {
Chris@16: private:
Chris@16:     CondT const& m_cond;
Chris@16: 
Chris@16: public:
Chris@16:     explicit if_gen(CondT const& cond) : m_cond(cond)
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     template< typename ThenT >
Chris@16:     BOOST_FORCEINLINE if_then_gen< CondT, ThenT > operator[] (ThenT const& then_) const
Chris@16:     {
Chris@16:         return if_then_gen< CondT, ThenT >(m_cond, then_);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: } // namespace aux
Chris@16: 
Chris@16: /*!
Chris@16:  * The function returns a conditional formatter generator object. The generator provides <tt>operator[]</tt> that can be used
Chris@16:  * to construct the actual formatter. The formatter must participate in a streaming expression.
Chris@16:  *
Chris@16:  * \param cond A filter expression that will be used as the condition
Chris@16:  */
Chris@16: template< typename CondT >
Chris@16: BOOST_FORCEINLINE aux::if_gen< CondT > if_(CondT const& cond)
Chris@16: {
Chris@16:     return aux::if_gen< CondT >(cond);
Chris@16: }
Chris@16: 
Chris@16: } // namespace expressions
Chris@16: 
Chris@16: BOOST_LOG_CLOSE_NAMESPACE // namespace log
Chris@16: 
Chris@16: #ifndef BOOST_LOG_DOXYGEN_PASS
Chris@16: 
Chris@16: namespace phoenix {
Chris@16: 
Chris@16: namespace result_of {
Chris@16: 
Chris@16: template< typename LeftT, typename CondT, typename ThenT >
Chris@16: struct is_nullary< custom_terminal< boost::log::expressions::aux::if_output_terminal< LeftT, CondT, ThenT > > > :
Chris@16:     public mpl::false_
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: template< typename LeftT, typename CondT, typename ThenT, typename ElseT >
Chris@16: struct is_nullary< custom_terminal< boost::log::expressions::aux::if_else_output_terminal< LeftT, CondT, ThenT, ElseT > > > :
Chris@16:     public mpl::false_
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: } // namespace result_of
Chris@16: 
Chris@16: } // namespace phoenix
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #include <boost/log/detail/footer.hpp>
Chris@16: 
Chris@16: #endif // BOOST_LOG_EXPRESSIONS_FORMATTERS_IF_HPP_INCLUDED_