/*
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* Copyright Andrey Semashev 2007 - 2015.
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* Distributed under the Boost Software License, Version 1.0.
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* (See accompanying file LICENSE_1_0.txt or copy at
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* http://www.boost.org/LICENSE_1_0.txt)
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*/
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/*!
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* \file formatters/if.hpp
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* \author Andrey Semashev
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* \date 17.11.2012
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*
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* The header contains implementation of a conditional formatter.
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*/
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#ifndef BOOST_LOG_EXPRESSIONS_FORMATTERS_IF_HPP_INCLUDED_
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#define BOOST_LOG_EXPRESSIONS_FORMATTERS_IF_HPP_INCLUDED_
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#include <boost/mpl/bool.hpp>
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#include <boost/phoenix/core/actor.hpp>
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#include <boost/phoenix/core/meta_grammar.hpp>
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#include <boost/phoenix/core/terminal_fwd.hpp>
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#include <boost/phoenix/core/is_nullary.hpp>
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#include <boost/phoenix/core/environment.hpp>
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#include <boost/fusion/sequence/intrinsic/at_c.hpp>
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#include <boost/type_traits/remove_cv.hpp>
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#include <boost/type_traits/remove_reference.hpp>
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#include <boost/log/detail/config.hpp>
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#include <boost/log/detail/custom_terminal_spec.hpp>
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#include <boost/log/detail/header.hpp>
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#ifdef BOOST_HAS_PRAGMA_ONCE
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#pragma once
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#endif
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namespace boost {
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BOOST_LOG_OPEN_NAMESPACE
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namespace expressions {
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namespace aux {
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template< typename LeftT, typename CondT, typename ThenT >
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class if_output_terminal
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{
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private:
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//! Self type
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typedef if_output_terminal this_type;
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public:
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#ifndef BOOST_LOG_DOXYGEN_PASS
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//! Internal typedef for type categorization
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typedef void _is_boost_log_terminal;
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#endif
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//! Result type definition
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template< typename >
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struct result;
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template< typename ThisT, typename ContextT >
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struct result< ThisT(ContextT) >
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{
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typedef typename remove_cv< typename remove_reference< ContextT >::type >::type context_type;
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typedef typename phoenix::evaluator::impl<
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typename LeftT::proto_base_expr&,
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context_type,
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phoenix::unused
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>::result_type type;
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};
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private:
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//! Left argument actor
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LeftT m_left;
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//! Condition expression
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CondT m_cond;
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//! Positive branch
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ThenT m_then;
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public:
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//! Initializing constructor
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if_output_terminal(LeftT const& left, CondT const& cond, ThenT const& then_) : m_left(left), m_cond(cond), m_then(then_)
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{
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}
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//! Invokation operator
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template< typename ContextT >
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typename result< this_type(ContextT const&) >::type operator() (ContextT const& ctx)
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{
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typedef typename result< this_type(ContextT const&) >::type result_type;
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result_type strm = phoenix::eval(m_left, ctx);
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if (phoenix::eval(m_cond, ctx))
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phoenix::eval(m_then, ctx);
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return strm;
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}
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//! Invokation operator
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template< typename ContextT >
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typename result< const this_type(ContextT const&) >::type operator() (ContextT const& ctx) const
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{
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typedef typename result< const this_type(ContextT const&) >::type result_type;
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result_type strm = phoenix::eval(m_left, ctx);
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if (phoenix::eval(m_cond, ctx))
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phoenix::eval(m_then, ctx);
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return strm;
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}
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BOOST_DELETED_FUNCTION(if_output_terminal())
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};
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template< typename LeftT, typename CondT, typename ThenT, typename ElseT >
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class if_else_output_terminal
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{
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private:
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//! Self type
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typedef if_else_output_terminal this_type;
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public:
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#ifndef BOOST_LOG_DOXYGEN_PASS
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//! Internal typedef for type categorization
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typedef void _is_boost_log_terminal;
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#endif
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//! Result type definition
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template< typename >
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struct result;
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template< typename ThisT, typename ContextT >
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struct result< ThisT(ContextT) >
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{
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typedef typename remove_cv< typename remove_reference< ContextT >::type >::type context_type;
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typedef typename phoenix::evaluator::impl<
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typename LeftT::proto_base_expr&,
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context_type,
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phoenix::unused
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>::result_type type;
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};
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private:
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//! Left argument actor
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LeftT m_left;
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//! Condition expression
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CondT m_cond;
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//! Positive branch
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ThenT m_then;
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//! Negative branch
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ElseT m_else;
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public:
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//! Initializing constructor
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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_)
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{
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}
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//! Invokation operator
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template< typename ContextT >
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typename result< this_type(ContextT const&) >::type operator() (ContextT const& ctx)
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{
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typedef typename result< this_type(ContextT const&) >::type result_type;
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result_type strm = phoenix::eval(m_left, ctx);
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if (phoenix::eval(m_cond, ctx))
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phoenix::eval(m_then, ctx);
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else
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phoenix::eval(m_else, ctx);
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return strm;
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}
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//! Invokation operator
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template< typename ContextT >
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typename result< const this_type(ContextT const&) >::type operator() (ContextT const& ctx) const
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{
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typedef typename result< const this_type(ContextT const&) >::type result_type;
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result_type strm = phoenix::eval(m_left, ctx);
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if (phoenix::eval(m_cond, ctx))
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phoenix::eval(m_then, ctx);
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else
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phoenix::eval(m_else, ctx);
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return strm;
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}
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BOOST_DELETED_FUNCTION(if_else_output_terminal())
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};
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template< typename CondT, typename ThenT, typename ElseT >
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struct if_then_else_gen
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{
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CondT m_cond;
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ThenT m_then;
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ElseT m_else;
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if_then_else_gen(CondT const& cond, ThenT const& then_, ElseT const& else_) : m_cond(cond), m_then(then_), m_else(else_)
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{
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}
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};
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#ifndef BOOST_LOG_DOXYGEN_PASS
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#define BOOST_LOG_AUX_OVERLOAD(left_ref, right_ref)\
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template< typename LeftExprT, typename CondT, typename ThenT, typename ElseT >\
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BOOST_FORCEINLINE phoenix::actor< if_else_output_terminal< phoenix::actor< LeftExprT >, CondT, ThenT, ElseT > >\
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operator<< (phoenix::actor< LeftExprT > left_ref left, if_then_else_gen< CondT, ThenT, ElseT > right_ref right)\
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{\
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typedef if_else_output_terminal< phoenix::actor< LeftExprT >, CondT, ThenT, ElseT > terminal_type;\
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phoenix::actor< terminal_type > actor = {{ terminal_type(left, right.m_cond, right.m_then, right.m_else) }};\
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return actor;\
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}
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#include <boost/log/detail/generate_overloads.hpp>
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#undef BOOST_LOG_AUX_OVERLOAD
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#endif // BOOST_LOG_DOXYGEN_PASS
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template< typename CondT, typename ThenT >
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struct if_then_gen
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{
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struct else_gen
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{
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CondT m_cond;
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ThenT m_then;
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else_gen(CondT const& cond, ThenT const& then_) : m_cond(cond), m_then(then_)
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{
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}
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template< typename ElseT >
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BOOST_FORCEINLINE if_then_else_gen< CondT, ThenT, ElseT > operator[] (ElseT const& el)
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{
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return if_then_else_gen< CondT, ThenT, ElseT >(m_cond, m_then, el);
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}
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}
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else_;
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if_then_gen(CondT const& cond, ThenT const& then_) : else_(cond, then_) {}
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};
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#ifndef BOOST_LOG_DOXYGEN_PASS
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#define BOOST_LOG_AUX_OVERLOAD(left_ref, right_ref)\
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template< typename LeftExprT, typename CondT, typename ThenT >\
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BOOST_FORCEINLINE phoenix::actor< if_output_terminal< phoenix::actor< LeftExprT >, CondT, ThenT > >\
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operator<< (phoenix::actor< LeftExprT > left_ref left, if_then_gen< CondT, ThenT > right_ref right)\
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{\
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typedef if_output_terminal< phoenix::actor< LeftExprT >, CondT, ThenT > terminal_type;\
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phoenix::actor< terminal_type > actor = {{ terminal_type(left, right.else_.m_cond, right.else_.m_then) }};\
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return actor;\
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}
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#include <boost/log/detail/generate_overloads.hpp>
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#undef BOOST_LOG_AUX_OVERLOAD
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#endif // BOOST_LOG_DOXYGEN_PASS
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template< typename CondT >
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class if_gen
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{
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private:
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CondT const& m_cond;
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public:
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explicit if_gen(CondT const& cond) : m_cond(cond)
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{
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}
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template< typename ThenT >
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BOOST_FORCEINLINE if_then_gen< CondT, ThenT > operator[] (ThenT const& then_) const
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{
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return if_then_gen< CondT, ThenT >(m_cond, then_);
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}
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};
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} // namespace aux
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/*!
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* The function returns a conditional formatter generator object. The generator provides <tt>operator[]</tt> that can be used
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* to construct the actual formatter. The formatter must participate in a streaming expression.
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*
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* \param cond A filter expression that will be used as the condition
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*/
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template< typename CondT >
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BOOST_FORCEINLINE aux::if_gen< CondT > if_(CondT const& cond)
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{
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return aux::if_gen< CondT >(cond);
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}
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} // namespace expressions
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BOOST_LOG_CLOSE_NAMESPACE // namespace log
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#ifndef BOOST_LOG_DOXYGEN_PASS
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namespace phoenix {
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namespace result_of {
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template< typename LeftT, typename CondT, typename ThenT >
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struct is_nullary< custom_terminal< boost::log::expressions::aux::if_output_terminal< LeftT, CondT, ThenT > > > :
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public mpl::false_
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{
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};
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template< typename LeftT, typename CondT, typename ThenT, typename ElseT >
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struct is_nullary< custom_terminal< boost::log::expressions::aux::if_else_output_terminal< LeftT, CondT, ThenT, ElseT > > > :
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public mpl::false_
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{
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};
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} // namespace result_of
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} // namespace phoenix
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#endif
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} // namespace boost
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#include <boost/log/detail/footer.hpp>
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#endif // BOOST_LOG_EXPRESSIONS_FORMATTERS_IF_HPP_INCLUDED_
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