ceph/src/boost/libs/spirit/include/boost/spirit/home/lex/meta_compiler.hpp

   1 //  Copyright (c) 2001-2011 Hartmut Kaiser
   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(BOOST_SPIRIT_LEX_META_COMPILER_APR_20_2009_0756PM)
   8 #define BOOST_SPIRIT_LEX_META_COMPILER_APR_20_2009_0756PM
   9
  10 #if defined(_MSC_VER)
  11 #pragma once
  12 #endif
  13
  14 #include <boost/spirit/home/support/meta_compiler.hpp>
  15 #include <boost/spirit/home/lex/domain.hpp>
  16 #include <boost/spirit/home/lex/lexer_type.hpp>
  17 #include <boost/type_traits/remove_reference.hpp>
  18 #include <boost/utility/enable_if.hpp>
  19
  20 namespace boost { namespace spirit
  21 {
  22     template <typename T>
  23     struct use_terminal<lex::domain, T
  24       , typename enable_if<traits::is_lexer<T> >::type> // enables lexers
  25       : mpl::true_ {};
  26
  27     namespace lex
  28     {
  29         template <typename T, typename Modifiers, typename Enable = void>
  30         struct make_primitive // by default, return it as-is
  31         {
  32             typedef T result_type;
  33
  34             template <typename T_>
  35             T_& operator()(T_& val, unused_type) const
  36             {
  37                 return val;
  38             }
  39
  40             template <typename T_>
  41             T_ const& operator()(T_ const& val, unused_type) const
  42             {
  43                 return val;
  44             }
  45         };
  46
  47         template <typename Tag, typename Elements
  48           , typename Modifiers, typename Enable = void>
  49         struct make_composite;
  50     }
  51
  52     // Lex primitive meta-compiler
  53     template <>
  54     struct make_component<lex::domain, proto::tag::terminal>
  55     {
  56         template <typename Sig>
  57         struct result;
  58
  59         template <typename This, typename Elements, typename Modifiers>
  60         struct result<This(Elements, Modifiers)>
  61         {
  62             typedef typename lex::make_primitive<
  63                 typename remove_const<typename Elements::car_type>::type,
  64                 typename remove_reference<Modifiers>::type>::result_type
  65             type;
  66         };
  67
  68         template <typename Elements, typename Modifiers>
  69         typename result<make_component(Elements, Modifiers)>::type
  70         operator()(Elements const& elements, Modifiers const& modifiers) const
  71         {
  72             typedef typename remove_const<typename Elements::car_type>::type term;
  73             return lex::make_primitive<term, Modifiers>()(elements.car, modifiers);
  74         }
  75     };
  76
  77     // Lex composite meta-compiler
  78     template <typename Tag>
  79     struct make_component<lex::domain, Tag>
  80     {
  81         template <typename Sig>
  82         struct result;
  83
  84         template <typename This, typename Elements, typename Modifiers>
  85         struct result<This(Elements, Modifiers)>
  86         {
  87             typedef typename
  88                 lex::make_composite<Tag, Elements
  89                   , typename remove_reference<Modifiers>::type>::result_type
  90             type;
  91         };
  92
  93         template <typename Elements, typename Modifiers>
  94         typename result<make_component(Elements, Modifiers)>::type
  95         operator()(Elements const& elements, Modifiers const& modifiers) const
  96         {
  97             return lex::make_composite<Tag, Elements, Modifiers>()(
  98                 elements, modifiers);
  99         }
 100     };
 101
 102 }}
 103
 104 #endif