ceph/src/boost/libs/metaparse/include/boost/metaparse/v1/keyword.hpp

   1 #ifndef BOOST_METAPARSE_V1_KEYWORD_HPP
   2 #define BOOST_METAPARSE_V1_KEYWORD_HPP
   3
   4 // Copyright Abel Sinkovics (abel@sinkovics.hu)  2009 - 2010.
   5 // Distributed under the Boost Software License, Version 1.0.
   6 //    (See accompanying file LICENSE_1_0.txt or copy at
   7 //          http://www.boost.org/LICENSE_1_0.txt)
   8
   9 #include <boost/metaparse/v1/impl/void_.hpp>
  10 #include <boost/metaparse/v1/lit.hpp>
  11 #include <boost/metaparse/v1/return_.hpp>
  12 #include <boost/metaparse/v1/is_error.hpp>
  13 #include <boost/metaparse/v1/get_remaining.hpp>
  14 #include <boost/metaparse/v1/get_position.hpp>
  15
  16 #include <boost/mpl/if.hpp>
  17 #include <boost/mpl/eval_if.hpp>
  18 #include <boost/mpl/empty.hpp>
  19 #include <boost/mpl/pop_front.hpp>
  20 #include <boost/mpl/front.hpp>
  21
  22 namespace boost
  23 {
  24   namespace metaparse
  25   {
  26     namespace v1
  27     {
  28       // Does not consume/check anything after the keyword
  29       template <class Kw, class ResultType = impl::void_>
  30       struct keyword
  31       {
  32       private:
  33         struct nonempty
  34         {
  35         private:
  36           typedef lit<typename boost::mpl::front<Kw>::type> next_char_parser;
  37
  38           typedef
  39             keyword<typename boost::mpl::pop_front<Kw>::type, ResultType>
  40             rest_parser;
  41
  42           template <class S, class Pos>
  43           struct apply_unchecked :
  44             rest_parser::template apply<
  45               typename get_remaining<
  46                 typename next_char_parser::template apply<S, Pos>
  47               >::type,
  48               typename get_position<
  49                 typename next_char_parser::template apply<S, Pos>
  50               >::type
  51             >
  52           {};
  53         public:
  54           template <class S, class Pos>
  55           struct apply :
  56             boost::mpl::eval_if<
  57               typename is_error<
  58                 typename next_char_parser::template apply<S, Pos>
  59               >::type,
  60               typename next_char_parser::template apply<S, Pos>,
  61               apply_unchecked<S, Pos>
  62             >
  63           {};
  64         };
  65       public:
  66         typedef keyword type;
  67
  68         template <class S, class Pos>
  69         struct apply :
  70           boost::mpl::if_<
  71             boost::mpl::empty<Kw>,
  72             return_<ResultType>,
  73             nonempty
  74           >::type::template apply<S, Pos>
  75         {};
  76       };
  77     }
  78   }
  79 }
  80
  81 #endif
  82