ceph/src/boost/libs/spirit/include/boost/spirit/home/qi/directive/hold.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 Joel de Guzman
   3
   4     Distributed under the Boost Software License, Version 1.0. (See accompanying
   5     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 =============================================================================*/
   7 #if !defined(SPIRIT_HOLD_FEBRUARY_6_2010_0917AM)
   8 #define SPIRIT_HOLD_FEBRUARY_6_2010_0917AM
   9
  10 #if defined(_MSC_VER)
  11 #pragma once
  12 #endif
  13
  14 #include <boost/spirit/home/qi/meta_compiler.hpp>
  15 #include <boost/spirit/home/qi/skip_over.hpp>
  16 #include <boost/spirit/home/qi/parser.hpp>
  17 #include <boost/spirit/home/support/attributes.hpp>
  18 #include <boost/spirit/home/support/info.hpp>
  19 #include <boost/spirit/home/support/common_terminals.hpp>
  20 #include <boost/spirit/home/support/unused.hpp>
  21 #include <boost/spirit/home/support/has_semantic_action.hpp>
  22 #include <boost/spirit/home/support/handles_container.hpp>
  23
  24 namespace boost { namespace spirit
  25 {
  26     ///////////////////////////////////////////////////////////////////////////
  27     // Enablers
  28     ///////////////////////////////////////////////////////////////////////////
  29     template <>
  30     struct use_directive<qi::domain, tag::hold> // enables hold
  31       : mpl::true_ {};
  32 }}
  33
  34 namespace boost { namespace spirit { namespace qi
  35 {
  36 #ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
  37     using spirit::hold;
  38 #endif
  39     using spirit::hold_type;
  40
  41     template <typename Subject>
  42     struct hold_directive : unary_parser<hold_directive<Subject> >
  43     {
  44         typedef Subject subject_type;
  45         hold_directive(Subject const& subject_)
  46           : subject(subject_) {}
  47
  48         template <typename Context, typename Iterator>
  49         struct attribute
  50         {
  51             typedef typename
  52                 traits::attribute_of<subject_type, Context, Iterator>::type
  53             type;
  54         };
  55
  56         template <typename Iterator, typename Context
  57           , typename Skipper, typename Attribute>
  58         bool parse(Iterator& first, Iterator const& last
  59           , Context& context, Skipper const& skipper, Attribute& attr_) const
  60         {
  61             Attribute copy(attr_);
  62             if (subject.parse(first, last, context, skipper, copy))
  63             {
  64                 traits::swap_impl(copy, attr_);
  65                 return true;
  66             }
  67             return false;
  68         }
  69
  70         template <typename Context>
  71         info what(Context& context) const
  72         {
  73             return info("hold", subject.what(context));
  74
  75         }
  76
  77         Subject subject;
  78     };
  79
  80     ///////////////////////////////////////////////////////////////////////////
  81     // Parser generators: make_xxx function (objects)
  82     ///////////////////////////////////////////////////////////////////////////
  83     template <typename Subject, typename Modifiers>
  84     struct make_directive<tag::hold, Subject, Modifiers>
  85     {
  86         typedef hold_directive<Subject> result_type;
  87         result_type operator()(unused_type, Subject const& subject, unused_type) const
  88         {
  89             return result_type(subject);
  90         }
  91     };
  92 }}}
  93
  94 namespace boost { namespace spirit { namespace traits
  95 {
  96     ///////////////////////////////////////////////////////////////////////////
  97     template <typename Subject>
  98     struct has_semantic_action<qi::hold_directive<Subject> >
  99       : unary_has_semantic_action<Subject> {};
 100
 101     ///////////////////////////////////////////////////////////////////////////
 102     template <typename Subject, typename Attribute, typename Context
 103         , typename Iterator>
 104     struct handles_container<qi::hold_directive<Subject>, Attribute
 105         , Context, Iterator>
 106       : unary_handles_container<Subject, Attribute, Context, Iterator> {};
 107 }}}
 108
 109 #endif