Chris@16: //  Copyright (c) 2001-2011 Joel de Guzman
Chris@16: //  Copyright (c) 2001-2011 Hartmut Kaiser
Chris@16: // 
Chris@16: //  Distributed under the Boost Software License, Version 1.0. (See accompanying 
Chris@16: //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #if !defined(BOOST_SPIRIT_KARMA_REFERENCE_APR_17_2009_1057PM)
Chris@16: #define BOOST_SPIRIT_KARMA_REFERENCE_APR_17_2009_1057PM
Chris@16: 
Chris@16: #if defined(_MSC_VER)
Chris@16: #pragma once
Chris@16: #endif
Chris@16: 
Chris@16: #include <boost/spirit/home/karma/meta_compiler.hpp>
Chris@16: #include <boost/spirit/home/karma/generator.hpp>
Chris@16: #include <boost/spirit/home/support/info.hpp>
Chris@16: #include <boost/spirit/home/support/handles_container.hpp>
Chris@16: #include <boost/type_traits/remove_const.hpp>
Chris@16: #include <boost/ref.hpp>
Chris@16: 
Chris@16: namespace boost { namespace spirit { namespace karma
Chris@16: {
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     // reference is a generator that references another generator (its Subject)
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename Subject>
Chris@16:     struct reference : generator<reference<Subject> >
Chris@16:     {
Chris@16:         typedef mpl::int_<generator_properties::all_properties> properties;
Chris@16: 
Chris@16:         typedef Subject subject_type;
Chris@16: 
Chris@16:         reference(Subject& subject)
Chris@16:           : ref(subject) {}
Chris@16: 
Chris@16:         template <typename Context, typename Unused>
Chris@16:         struct attribute : Subject::template attribute<Context, Unused> {};
Chris@16: 
Chris@16:         // Default overload, used whenever the attribute is not unused and not
Chris@16:         // used from an aliased rule.
Chris@16:         template <typename OutputIterator, typename Context
Chris@16:           , typename Delimiter, typename Attribute>
Chris@16:         bool generate(OutputIterator& sink, Context& context
Chris@16:           , Delimiter const& delim, Attribute const& attr) const
Chris@16:         {
Chris@16:             return ref.get().generate(sink, context, delim, attr);
Chris@16:         }
Chris@16: 
Chris@16:         // This overload gets called from an aliased rule only, we take the 
Chris@16:         // attribute from the context provided from the wrapper rule.
Chris@16:         template <typename OutputIterator, typename Context
Chris@16:           , typename Delimiter>
Chris@16:         bool generate(OutputIterator& sink, Context& context
Chris@16:           , Delimiter const& delim, unused_type) const
Chris@16:         {
Chris@16:             return ref.get().generate(sink, context, delim, context.attributes);
Chris@16:         }
Chris@16: 
Chris@16:         // This overload is used whenever no attribute is given and it is used
Chris@16:         // not from an aliased rule.
Chris@16:         template <typename OutputIterator, typename Delimiter>
Chris@16:         bool generate(OutputIterator& sink, unused_type
Chris@16:           , Delimiter const& delim, unused_type) const
Chris@16:         {
Chris@16:             return ref.get().generate(sink, unused, delim, unused);
Chris@16:         }
Chris@16: 
Chris@16:         template <typename Context>
Chris@16:         info what(Context& context) const
Chris@16:         {
Chris@16:             // the reference is transparent (does not add any info)
Chris@16:             return ref.get().what(context);
Chris@16:         }
Chris@16: 
Chris@16:         boost::reference_wrapper<Subject> ref;
Chris@16:     };
Chris@16: }}}
Chris@16: 
Chris@16: namespace boost { namespace spirit { namespace traits
Chris@16: {
Chris@16:     ///////////////////////////////////////////////////////////////////////////
Chris@16:     template <typename Subject, typename Attribute, typename Context
Chris@16:       , typename Iterator>
Chris@16:     struct handles_container<karma::reference<Subject>, Attribute
Chris@16:       , Context, Iterator>
Chris@16:       : handles_container<typename remove_const<Subject>::type, Attribute
Chris@16:         , Context, Iterator> 
Chris@16:     {};
Chris@16: }}}
Chris@16: 
Chris@16: #endif