boost/typeof/template_encoding.hpp

   1 // Copyright (C) 2004 Arkadiy Vertleyb
   2 // Copyright (C) 2005 Peder Holt
   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 #ifndef BOOST_TYPEOF_TEMPLATE_ENCODING_HPP_INCLUDED
   7 #define BOOST_TYPEOF_TEMPLATE_ENCODING_HPP_INCLUDED
   8
   9 #include <boost/preprocessor/cat.hpp>
  10 #include <boost/preprocessor/repetition/enum_trailing.hpp>
  11 #include <boost/preprocessor/control/iif.hpp>
  12 #include <boost/preprocessor/detail/is_unary.hpp>
  13 #include <boost/preprocessor/repetition/repeat.hpp>
  14 #include <boost/preprocessor/tuple/eat.hpp>
  15 #include <boost/preprocessor/seq/transform.hpp>
  16 #include <boost/preprocessor/seq/for_each_i.hpp>
  17 #include <boost/preprocessor/seq/cat.hpp>
  18
  19 #include <boost/typeof/encode_decode.hpp>
  20 #include <boost/typeof/int_encoding.hpp>
  21
  22 #include <boost/typeof/type_template_param.hpp>
  23 #include <boost/typeof/integral_template_param.hpp>
  24 #include <boost/typeof/template_template_param.hpp>
  25
  26 // The template parameter description, entered by the user,
  27 // is converted into a polymorphic "object"
  28 // that is used to generate the code responsible for
  29 // encoding/decoding the parameter, etc.
  30
  31 // make sure to cat the sequence first, and only then add the prefix.
  32 #define BOOST_TYPEOF_MAKE_OBJ(elem) BOOST_PP_CAT(\
  33     BOOST_TYPEOF_MAKE_OBJ,\
  34     BOOST_PP_SEQ_CAT((_) BOOST_TYPEOF_TO_SEQ(elem))\
  35     )
  36
  37 #define BOOST_TYPEOF_TO_SEQ(tokens) BOOST_TYPEOF_ ## tokens ## _BOOST_TYPEOF
  38
  39 // BOOST_TYPEOF_REGISTER_TEMPLATE
  40
  41 #define BOOST_TYPEOF_REGISTER_TEMPLATE_EXPLICIT_ID(Name, Params, Id)\
  42     BOOST_TYPEOF_REGISTER_TEMPLATE_IMPL(\
  43         Name,\
  44         BOOST_TYPEOF_MAKE_OBJS(BOOST_TYPEOF_TOSEQ(Params)),\
  45         BOOST_PP_SEQ_SIZE(BOOST_TYPEOF_TOSEQ(Params)),\
  46         Id)
  47
  48 #define BOOST_TYPEOF_REGISTER_TEMPLATE(Name, Params)\
  49     BOOST_TYPEOF_REGISTER_TEMPLATE_EXPLICIT_ID(Name, Params, BOOST_TYPEOF_UNIQUE_ID())
  50
  51 #define BOOST_TYPEOF_OBJECT_MAKER(s, data, elem)\
  52     BOOST_TYPEOF_MAKE_OBJ(elem)
  53
  54 #define BOOST_TYPEOF_MAKE_OBJS(Params)\
  55     BOOST_PP_SEQ_TRANSFORM(BOOST_TYPEOF_OBJECT_MAKER, ~, Params)
  56
  57 // As suggested by Paul Mensonides:
  58
  59 #define BOOST_TYPEOF_TOSEQ(x)\
  60     BOOST_PP_IIF(\
  61         BOOST_PP_IS_UNARY(x),\
  62         x BOOST_PP_TUPLE_EAT(3), BOOST_PP_REPEAT\
  63     )(x, BOOST_TYPEOF_TOSEQ_2, ~)
  64
  65 #define BOOST_TYPEOF_TOSEQ_2(z, n, _) (class)
  66
  67 // BOOST_TYPEOF_VIRTUAL
  68
  69 #define BOOST_TYPEOF_CAT_4(a, b, c, d) BOOST_TYPEOF_CAT_4_I(a, b, c, d)
  70 #define BOOST_TYPEOF_CAT_4_I(a, b, c, d) a ## b ## c ## d
  71
  72 #define BOOST_TYPEOF_VIRTUAL(Fun, Obj)\
  73     BOOST_TYPEOF_CAT_4(BOOST_TYPEOF_, BOOST_PP_SEQ_HEAD(Obj), _, Fun)
  74
  75 // BOOST_TYPEOF_SEQ_ENUM[_TRAILING][_1]
  76 // Two versions provided due to reentrancy issue
  77
  78 #define BOOST_TYPEOF_SEQ_EXPAND_ELEMENT(z,n,seq)\
  79    BOOST_PP_SEQ_ELEM(0,seq) (z,n,BOOST_PP_SEQ_ELEM(n,BOOST_PP_SEQ_ELEM(1,seq)))
  80
  81 #define BOOST_TYPEOF_SEQ_ENUM(seq,macro)\
  82     BOOST_PP_ENUM(BOOST_PP_SEQ_SIZE(seq),BOOST_TYPEOF_SEQ_EXPAND_ELEMENT,(macro)(seq))
  83
  84 #define BOOST_TYPEOF_SEQ_ENUM_TRAILING(seq,macro)\
  85     BOOST_PP_ENUM_TRAILING(BOOST_PP_SEQ_SIZE(seq),BOOST_TYPEOF_SEQ_EXPAND_ELEMENT,(macro)(seq))
  86
  87 #define BOOST_TYPEOF_SEQ_EXPAND_ELEMENT_1(z,n,seq)\
  88     BOOST_PP_SEQ_ELEM(0,seq) (z,n,BOOST_PP_SEQ_ELEM(n,BOOST_PP_SEQ_ELEM(1,seq)))
  89
  90 #define BOOST_TYPEOF_SEQ_ENUM_1(seq,macro)\
  91     BOOST_PP_ENUM(BOOST_PP_SEQ_SIZE(seq),BOOST_TYPEOF_SEQ_EXPAND_ELEMENT_1,(macro)(seq))
  92
  93 #define BOOST_TYPEOF_SEQ_ENUM_TRAILING_1(seq,macro)\
  94     BOOST_PP_ENUM_TRAILING(BOOST_PP_SEQ_SIZE(seq),BOOST_TYPEOF_SEQ_EXPAND_ELEMENT_1,(macro)(seq))
  95
  96 //
  97
  98 #define BOOST_TYPEOF_PLACEHOLDER(z, n, elem)\
  99     BOOST_TYPEOF_VIRTUAL(PLACEHOLDER, elem)(elem)
 100
 101 #define BOOST_TYPEOF_PLACEHOLDER_TYPES(z, n, elem)\
 102     BOOST_TYPEOF_VIRTUAL(PLACEHOLDER_TYPES, elem)(elem, n)
 103
 104 #define BOOST_TYPEOF_REGISTER_TEMPLATE_ENCODE_PARAM(r, data, n, elem)\
 105     BOOST_TYPEOF_VIRTUAL(ENCODE, elem)(elem, n)
 106
 107 #define BOOST_TYPEOF_REGISTER_TEMPLATE_DECODE_PARAM(r, data, n, elem)\
 108     BOOST_TYPEOF_VIRTUAL(DECODE, elem)(elem, n)
 109
 110 #define BOOST_TYPEOF_REGISTER_TEMPLATE_PARAM_PAIR(z, n, elem) \
 111     BOOST_TYPEOF_VIRTUAL(EXPANDTYPE, elem)(elem) BOOST_PP_CAT(P, n)
 112
 113 #define BOOST_TYPEOF_REGISTER_DEFAULT_TEMPLATE_TYPE(Name,Params,ID)\
 114     Name< BOOST_PP_ENUM_PARAMS(BOOST_PP_SEQ_SIZE(Params), P) >
 115
 116 //Since we are creating an internal decode struct, we need to use different template names, T instead of P.
 117 #define BOOST_TYPEOF_REGISTER_DECODER_TYPE_PARAM_PAIR(z,n,elem) \
 118     BOOST_TYPEOF_VIRTUAL(EXPANDTYPE, elem)(elem) BOOST_PP_CAT(T, n)
 119
 120 //Default template param decoding
 121 #define BOOST_TYPEOF_TYPEDEF_DECODED_TEMPLATE_TYPE(Name,Params)\
 122     typedef Name<BOOST_PP_ENUM_PARAMS(BOOST_PP_SEQ_SIZE(Params),P)> type;
 123
 124 //Branch the decoding
 125 #define BOOST_TYPEOF_TYPEDEF_DECODED_TYPE(Name,Params)\
 126     BOOST_PP_IF(BOOST_TYPEOF_HAS_TEMPLATES(Params),\
 127         BOOST_TYPEOF_TYPEDEF_DECODED_TEMPLATE_TEMPLATE_TYPE,\
 128         BOOST_TYPEOF_TYPEDEF_DECODED_TEMPLATE_TYPE)(Name,Params)
 129
 130 #define BOOST_TYPEOF_REGISTER_TEMPLATE_IMPL(Name, Params, Size, ID)\
 131     BOOST_TYPEOF_BEGIN_ENCODE_NS\
 132     BOOST_TYPEOF_REGISTER_TEMPLATE_TEMPLATE_IMPL(Name, Params, ID)\
 133     template<class V\
 134         BOOST_TYPEOF_SEQ_ENUM_TRAILING(Params, BOOST_TYPEOF_REGISTER_TEMPLATE_PARAM_PAIR)\
 135     >\
 136     struct encode_type_impl<V, Name<BOOST_PP_ENUM_PARAMS(Size, P)> >\
 137     {\
 138         typedef typename boost::type_of::push_back<V, boost::mpl::size_t<ID> >::type V0;\
 139         BOOST_PP_SEQ_FOR_EACH_I(BOOST_TYPEOF_REGISTER_TEMPLATE_ENCODE_PARAM, ~, Params)\
 140         typedef BOOST_PP_CAT(V, Size) type;\
 141     };\
 142     template<class Iter>\
 143     struct decode_type_impl<boost::mpl::size_t<ID>, Iter>\
 144     {\
 145         typedef Iter iter0;\
 146         BOOST_PP_SEQ_FOR_EACH_I(BOOST_TYPEOF_REGISTER_TEMPLATE_DECODE_PARAM, ~, Params)\
 147         BOOST_TYPEOF_TYPEDEF_DECODED_TYPE(Name, Params)\
 148         typedef BOOST_PP_CAT(iter, Size) iter;\
 149     };\
 150     BOOST_TYPEOF_END_ENCODE_NS
 151
 152 #endif//BOOST_TYPEOF_TEMPLATE_ENCODING_HPP_INCLUDED