ceph/src/boost/boost/spirit/home/karma/directive/duplicate.hpp

   1 //  Copyright (c) 2001-2011 Hartmut Kaiser
   2 //
   3 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
   4 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   5
   6 #if !defined(SPIRIT_KARMA_DUPLICATE_JUL_11_2010_0954AM)
   7 #define SPIRIT_KARMA_DUPLICATE_JUL_11_2010_0954AM
   8
   9 #if defined(_MSC_VER)
  10 #pragma once
  11 #endif
  12
  13 #include <boost/spirit/home/karma/meta_compiler.hpp>
  14 #include <boost/spirit/home/karma/generator.hpp>
  15 #include <boost/spirit/home/karma/domain.hpp>
  16 #include <boost/spirit/home/karma/detail/attributes.hpp>
  17 #include <boost/spirit/home/support/unused.hpp>
  18 #include <boost/spirit/home/support/info.hpp>
  19 #include <boost/spirit/home/support/common_terminals.hpp>
  20 #include <boost/spirit/home/support/assert_msg.hpp>
  21 #include <boost/spirit/home/support/has_semantic_action.hpp>
  22 #include <boost/spirit/home/support/handles_container.hpp>
  23 #include <boost/fusion/include/cons.hpp>
  24 #include <boost/fusion/include/make_cons.hpp>
  25 #include <boost/fusion/include/vector.hpp>
  26 #include <boost/fusion/include/at_c.hpp>
  27 #include <boost/mpl/identity.hpp>
  28 #include <boost/mpl/bool.hpp>
  29
  30 namespace boost { namespace spirit
  31 {
  32     ///////////////////////////////////////////////////////////////////////////
  33     // Enablers
  34     ///////////////////////////////////////////////////////////////////////////
  35     template <>
  36     struct use_directive<karma::domain, tag::duplicate> // enables duplicate
  37       : mpl::true_ {};
  38 }}
  39
  40 namespace boost { namespace spirit { namespace karma
  41 {
  42 #ifndef BOOST_SPIRIT_NO_PREDEFINED_TERMINALS
  43     using spirit::duplicate;
  44 #endif
  45     using spirit::duplicate_type;
  46
  47     ///////////////////////////////////////////////////////////////////////////
  48     namespace detail
  49     {
  50         ///////////////////////////////////////////////////////////////////////
  51         template <typename T
  52           , bool IsSequence = fusion::traits::is_sequence<T>::value>
  53         struct attribute_count
  54           : fusion::result_of::size<T>
  55         {};
  56
  57         template <>
  58         struct attribute_count<unused_type, false>
  59           : mpl::int_<0>
  60         {};
  61
  62         template <typename T>
  63         struct attribute_count<T, false>
  64           : mpl::int_<1>
  65         {};
  66
  67         ///////////////////////////////////////////////////////////////////////
  68         template <typename T
  69           , bool IsSequence = fusion::traits::is_sequence<T>::value>
  70         struct first_attribute_of_subject
  71           : remove_reference<typename fusion::result_of::at_c<T, 0>::type>
  72         {};
  73
  74         template <typename T>
  75         struct first_attribute_of_subject<T, false>
  76           : mpl::identity<T>
  77         {};
  78
  79         template <typename T, typename Context, typename Iterator>
  80         struct first_attribute_of
  81           : first_attribute_of_subject<
  82                 typename traits::attribute_of<T, Context, Iterator>::type>
  83         {};
  84
  85         ///////////////////////////////////////////////////////////////////////
  86         template <typename Attribute, typename T, int N>
  87         struct duplicate_sequence_attribute
  88         {
  89             typedef typename fusion::result_of::make_cons<
  90                 reference_wrapper<T const>
  91               , typename duplicate_sequence_attribute<Attribute, T, N-1>::type
  92             >::type type;
  93
  94             static type call(T const& t)
  95             {
  96                 return fusion::make_cons(boost::cref(t)
  97                   , duplicate_sequence_attribute<Attribute, T, N-1>::call(t));
  98             }
  99         };
 100
 101         template <typename Attribute, typename T>
 102         struct duplicate_sequence_attribute<Attribute, T, 1>
 103         {
 104             typedef typename fusion::result_of::make_cons<
 105                 reference_wrapper<T const> >::type type;
 106
 107             static type call(T const& t)
 108             {
 109                 return fusion::make_cons(boost::cref(t));
 110             }
 111         };
 112
 113         ///////////////////////////////////////////////////////////////////////
 114         template <typename Attribute, typename T
 115           , int N = attribute_count<Attribute>::value
 116           , bool IsSequence = fusion::traits::is_sequence<Attribute>::value>
 117         struct duplicate_attribute
 118         {
 119             BOOST_SPIRIT_ASSERT_MSG(N > 0, invalid_duplication_count, (Attribute));
 120
 121             typedef typename duplicate_sequence_attribute<Attribute, T, N>::type
 122                 cons_type;
 123             typedef typename fusion::result_of::as_vector<cons_type>::type type;
 124
 125             static type call(T const& t)
 126             {
 127                 return fusion::as_vector(
 128                     duplicate_sequence_attribute<Attribute, T, N>::call(t));
 129             }
 130         };
 131
 132         template <typename Attribute, typename T>
 133         struct duplicate_attribute<Attribute, T, 0, false>
 134         {
 135             typedef unused_type type;
 136
 137             static type call(T const&)
 138             {
 139                 return unused;
 140             }
 141         };
 142
 143         template <typename Attribute, typename T, int N>
 144         struct duplicate_attribute<Attribute, T, N, false>
 145         {
 146             typedef Attribute const& type;
 147
 148             static type call(T const& t)
 149             {
 150                 return t;
 151             }
 152         };
 153     }
 154
 155     template <typename Attribute, typename T>
 156     inline typename detail::duplicate_attribute<Attribute, T>::type
 157     duplicate_attribute(T const& t)
 158     {
 159         return detail::duplicate_attribute<Attribute, T>::call(t);
 160     }
 161
 162     ///////////////////////////////////////////////////////////////////////////
 163     // duplicate_directive duplicate its attribute for all elements of the
 164     // subject generator without generating anything itself
 165     ///////////////////////////////////////////////////////////////////////////
 166     template <typename Subject>
 167     struct duplicate_directive : unary_generator<duplicate_directive<Subject> >
 168     {
 169         typedef Subject subject_type;
 170         typedef typename subject_type::properties properties;
 171
 172         duplicate_directive(Subject const& subject)
 173           : subject(subject) {}
 174
 175         template <typename Context, typename Iterator = unused_type>
 176         struct attribute
 177           : detail::first_attribute_of<Subject, Context, Iterator>
 178         {};
 179
 180         template <typename OutputIterator, typename Context, typename Delimiter
 181           , typename Attribute>
 182         bool generate(OutputIterator& sink, Context& ctx, Delimiter const& d
 183           , Attribute const& attr) const
 184         {
 185             typedef typename traits::attribute_of<Subject, Context>::type
 186                 subject_attr_type;
 187             return subject.generate(sink, ctx, d
 188               , duplicate_attribute<subject_attr_type>(attr));
 189         }
 190
 191         template <typename Context>
 192         info what(Context& context) const
 193         {
 194             return info("duplicate", subject.what(context));
 195         }
 196
 197         Subject subject;
 198     };
 199
 200     ///////////////////////////////////////////////////////////////////////////
 201     // Generator generators: make_xxx function (objects)
 202     ///////////////////////////////////////////////////////////////////////////
 203     template <typename Subject, typename Modifiers>
 204     struct make_directive<tag::duplicate, Subject, Modifiers>
 205     {
 206         typedef duplicate_directive<Subject> result_type;
 207         result_type operator()(unused_type, Subject const& subject
 208           , unused_type) const
 209         {
 210             return result_type(subject);
 211         }
 212     };
 213 }}}
 214
 215 namespace boost { namespace spirit { namespace traits
 216 {
 217     ///////////////////////////////////////////////////////////////////////////
 218     template <typename Subject>
 219     struct has_semantic_action<karma::duplicate_directive<Subject> >
 220       : unary_has_semantic_action<Subject> {};
 221
 222     ///////////////////////////////////////////////////////////////////////////
 223     template <typename Subject, typename Attribute, typename Context
 224         , typename Iterator>
 225     struct handles_container<karma::duplicate_directive<Subject>, Attribute
 226         , Context, Iterator>
 227       : unary_handles_container<Subject, Attribute, Context, Iterator> {};
 228 }}}
 229
 230 #endif