ceph/src/boost/libs/spirit/include/boost/spirit/home/qi/operator/plus.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 Joel de Guzman
   3     Copyright (c) 2001-2011 Hartmut Kaiser
   4
   5     Distributed under the Boost Software License, Version 1.0. (See accompanying
   6     file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   7 =============================================================================*/
   8 #if !defined(SPIRIT_PLUS_MARCH_13_2007_0127PM)
   9 #define SPIRIT_PLUS_MARCH_13_2007_0127PM
  10
  11 #if defined(_MSC_VER)
  12 #pragma once
  13 #endif
  14
  15 #include <boost/spirit/home/qi/meta_compiler.hpp>
  16 #include <boost/spirit/home/qi/parser.hpp>
  17 #include <boost/spirit/home/support/container.hpp>
  18 #include <boost/spirit/home/qi/detail/attributes.hpp>
  19 #include <boost/spirit/home/qi/detail/fail_function.hpp>
  20 #include <boost/spirit/home/qi/detail/pass_container.hpp>
  21 #include <boost/spirit/home/support/has_semantic_action.hpp>
  22 #include <boost/spirit/home/support/handles_container.hpp>
  23 #include <boost/spirit/home/support/info.hpp>
  24
  25 namespace boost { namespace spirit
  26 {
  27     ///////////////////////////////////////////////////////////////////////////
  28     // Enablers
  29     ///////////////////////////////////////////////////////////////////////////
  30     template <>
  31     struct use_operator<qi::domain, proto::tag::unary_plus> // enables +p
  32       : mpl::true_ {};
  33 }}
  34
  35 namespace boost { namespace spirit { namespace qi
  36 {
  37     template <typename Subject>
  38     struct plus : unary_parser<plus<Subject> >
  39     {
  40         typedef Subject subject_type;
  41
  42         template <typename Context, typename Iterator>
  43         struct attribute
  44         {
  45             // Build a std::vector from the subject's attribute. Note
  46             // that build_std_vector may return unused_type if the
  47             // subject's attribute is an unused_type.
  48             typedef typename
  49                 traits::build_std_vector<
  50                     typename traits::attribute_of<
  51                         Subject, Context, Iterator>::type
  52                 >::type
  53             type;
  54         };
  55
  56         plus(Subject const& subject_)
  57           : subject(subject_) {}
  58
  59         template <typename F>
  60         bool parse_container(F f) const
  61         {
  62             // in order to succeed we need to match at least one element
  63             if (f (subject))
  64                 return false;
  65
  66             while (!f (subject))
  67                 ;
  68             return true;
  69         }
  70
  71         template <typename Iterator, typename Context
  72           , typename Skipper, typename Attribute>
  73         bool parse(Iterator& first, Iterator const& last
  74           , Context& context, Skipper const& skipper
  75           , Attribute& attr_) const
  76         {
  77             typedef detail::fail_function<Iterator, Context, Skipper>
  78                 fail_function;
  79
  80             // ensure the attribute is actually a container type
  81             traits::make_container(attr_);
  82
  83             Iterator iter = first;
  84             fail_function f(iter, last, context, skipper);
  85             if (!parse_container(detail::make_pass_container(f, attr_)))
  86                 return false;
  87
  88             first = f.first;
  89             return true;
  90         }
  91
  92         template <typename Context>
  93         info what(Context& context) const
  94         {
  95             return info("plus", subject.what(context));
  96         }
  97
  98         Subject subject;
  99     };
 100
 101     ///////////////////////////////////////////////////////////////////////////
 102     // Parser generators: make_xxx function (objects)
 103     ///////////////////////////////////////////////////////////////////////////
 104     template <typename Elements, typename Modifiers>
 105     struct make_composite<proto::tag::unary_plus, Elements, Modifiers>
 106       : make_unary_composite<Elements, plus>
 107     {};
 108 }}}
 109
 110 namespace boost { namespace spirit { namespace traits
 111 {
 112     ///////////////////////////////////////////////////////////////////////////
 113     template <typename Subject>
 114     struct has_semantic_action<qi::plus<Subject> >
 115       : unary_has_semantic_action<Subject> {};
 116
 117     ///////////////////////////////////////////////////////////////////////////
 118     template <typename Subject, typename Attribute, typename Context
 119       , typename Iterator>
 120     struct handles_container<qi::plus<Subject>, Attribute, Context
 121           , Iterator>
 122       : mpl::true_ {};
 123 }}}
 124
 125 #endif