ceph/src/boost/libs/spirit/include/boost/spirit/home/qi/auxiliary/attr.hpp

   1 /*=============================================================================
   2     Copyright (c) 2001-2011 Hartmut Kaiser
   3     Copyright (c) 2001-2011 Joel de Guzman
   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(BOOST_SPIRIT_ATTR_JUL_23_2008_0956AM)
   9 #define BOOST_SPIRIT_ATTR_JUL_23_2008_0956AM
  10
  11 #if defined(_MSC_VER)
  12 #pragma once
  13 #endif
  14
  15 #include <boost/mpl/bool.hpp>
  16 #include <boost/spirit/home/qi/domain.hpp>
  17 #include <boost/spirit/home/qi/parser.hpp>
  18 #include <boost/spirit/home/qi/detail/assign_to.hpp>
  19 #include <boost/spirit/home/qi/meta_compiler.hpp>
  20 #include <boost/spirit/home/support/common_terminals.hpp>
  21 #include <boost/spirit/home/support/handles_container.hpp>
  22 #include <boost/type_traits/add_reference.hpp>
  23 #include <boost/type_traits/add_const.hpp>
  24 #include <boost/type_traits/remove_const.hpp>
  25
  26 namespace boost { namespace spirit
  27 {
  28     ///////////////////////////////////////////////////////////////////////////
  29     // Enablers
  30     ///////////////////////////////////////////////////////////////////////////
  31     template <typename A0>       // enables attr()
  32     struct use_terminal<
  33             qi::domain, terminal_ex<tag::attr, fusion::vector1<A0> > >
  34       : mpl::true_ {};
  35
  36     template <>                  // enables *lazy* attr()
  37     struct use_lazy_terminal<qi::domain, tag::attr, 1>
  38       : mpl::true_ {};
  39
  40 }}
  41
  42 namespace boost { namespace spirit { namespace qi
  43 {
  44 #ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
  45     using spirit::attr;
  46 #endif
  47     using spirit::attr_type;
  48
  49     template <typename Value>
  50     struct attr_parser : primitive_parser<attr_parser<Value> >
  51     {
  52         template <typename Context, typename Iterator>
  53         struct attribute : remove_const<Value> {};
  54
  55         attr_parser(typename add_reference<Value>::type value)
  56           : value_(value) {}
  57
  58         template <typename Iterator, typename Context
  59           , typename Skipper, typename Attribute>
  60         bool parse(Iterator& /*first*/, Iterator const& /*last*/
  61           , Context& /*context*/, Skipper const& /*skipper*/
  62           , Attribute& attr_) const
  63         {
  64             spirit::traits::assign_to(value_, attr_);
  65             return true;        // never consume any input, succeed always
  66         }
  67
  68         template <typename Context>
  69         info what(Context& /*context*/) const
  70         {
  71             return info("attr");
  72         }
  73
  74         Value value_;
  75
  76     private:
  77         // silence MSVC warning C4512: assignment operator could not be generated
  78         attr_parser& operator= (attr_parser const&);
  79     };
  80
  81     ///////////////////////////////////////////////////////////////////////////
  82     // Parser generators: make_xxx function (objects)
  83     ///////////////////////////////////////////////////////////////////////////
  84     template <typename Modifiers, typename A0>
  85     struct make_primitive<
  86         terminal_ex<tag::attr, fusion::vector1<A0> >
  87       , Modifiers>
  88     {
  89         typedef typename add_const<A0>::type const_value;
  90         typedef attr_parser<const_value> result_type;
  91
  92         template <typename Terminal>
  93         result_type operator()(Terminal const& term, unused_type) const
  94         {
  95             return result_type(fusion::at_c<0>(term.args));
  96         }
  97     };
  98 }}}
  99
 100 namespace boost { namespace spirit { namespace traits
 101 {
 102     ///////////////////////////////////////////////////////////////////////////
 103     template <typename T, typename Attr, typename Context, typename Iterator>
 104     struct handles_container<qi::attr_parser<T>, Attr, Context, Iterator>
 105       : traits::is_container<Attr> {};
 106 }}}
 107
 108 #endif
 109
 110