| // Copyright (c) 2001-2010 Joel de Guzman |
| // Copyright (c) 2001-2010 Hartmut Kaiser |
| // |
| // Distributed under the Boost Software License, Version 1.0. (See accompanying |
| // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) |
| |
| #if !defined(BOOST_SPIRIT_KARMA_REFERENCE_APR_17_2009_1057PM) |
| #define BOOST_SPIRIT_KARMA_REFERENCE_APR_17_2009_1057PM |
| |
| #if defined(_MSC_VER) |
| #pragma once |
| #endif |
| |
| #include <boost/spirit/home/karma/meta_compiler.hpp> |
| #include <boost/spirit/home/karma/generator.hpp> |
| #include <boost/spirit/home/support/info.hpp> |
| #include <boost/ref.hpp> |
| |
| namespace boost { namespace spirit { namespace karma |
| { |
| /////////////////////////////////////////////////////////////////////////// |
| // reference is a generator that references another generator (its Subject) |
| /////////////////////////////////////////////////////////////////////////// |
| template <typename Subject> |
| struct reference : generator<reference<Subject> > |
| { |
| typedef mpl::int_<generator_properties::all_properties> properties; |
| |
| typedef Subject subject_type; |
| |
| reference(Subject& subject) |
| : ref(subject) {} |
| |
| template <typename Context, typename Unused> |
| struct attribute : Subject::template attribute<Context, Unused> {}; |
| |
| // Default overload, used whenever the attribute is not unused and not |
| // used from an aliased rule. |
| template <typename OutputIterator, typename Context |
| , typename Delimiter, typename Attribute> |
| bool generate(OutputIterator& sink, Context& context |
| , Delimiter const& delim, Attribute const& attr) const |
| { |
| return ref.get().generate(sink, context, delim, attr); |
| } |
| |
| // This overload gets called from an aliased rule only, we take the |
| // attribute from the context provided from the wrapper rule. |
| template <typename OutputIterator, typename Context |
| , typename Delimiter> |
| bool generate(OutputIterator& sink, Context& context |
| , Delimiter const& delim, unused_type) const |
| { |
| return ref.get().generate(sink, context, delim, context.attributes); |
| } |
| |
| // This overload is used whenever no attribute is given and it is used |
| // not from an aliased rule. |
| template <typename OutputIterator, typename Delimiter> |
| bool generate(OutputIterator& sink, unused_type |
| , Delimiter const& delim, unused_type) const |
| { |
| return ref.get().generate(sink, unused, delim, unused); |
| } |
| |
| template <typename Context> |
| info what(Context& context) const |
| { |
| // the reference is transparent (does not add any info) |
| return ref.get().what(context); |
| } |
| |
| boost::reference_wrapper<Subject> ref; |
| }; |
| |
| }}} |
| |
| #endif |