boost/mpl/aux_/template_arity.hpp

   1
   2 #if !defined(BOOST_PP_IS_ITERATING)
   3
   4 ///// header body
   5
   6 #ifndef BOOST_MPL_AUX_TEMPLATE_ARITY_HPP_INCLUDED
   7 #define BOOST_MPL_AUX_TEMPLATE_ARITY_HPP_INCLUDED
   8
   9 // Copyright Aleksey Gurtovoy 2001-2004
  10 //
  11 // Distributed under the Boost Software License, Version 1.0.
  12 // (See accompanying file LICENSE_1_0.txt or copy at
  13 // http://www.boost.org/LICENSE_1_0.txt)
  14 //
  15 // See http://www.boost.org/libs/mpl for documentation.
  16
  17 // $Id: template_arity.hpp 61584 2010-04-26 18:48:26Z agurtovoy $
  18 // $Date: 2010-04-26 11:48:26 -0700 (Mon, 26 Apr 2010) $
  19 // $Revision: 61584 $
  20
  21 #include <boost/mpl/aux_/config/ttp.hpp>
  22 #include <boost/mpl/aux_/config/lambda.hpp>
  23
  24 #if !defined(BOOST_MPL_PREPROCESSING_MODE)
  25 #   include <boost/mpl/aux_/template_arity_fwd.hpp>
  26 #   include <boost/mpl/int.hpp>
  27 #   if !defined(BOOST_MPL_CFG_NO_FULL_LAMBDA_SUPPORT)
  28 #   if defined(BOOST_MPL_CFG_EXTENDED_TEMPLATE_PARAMETERS_MATCHING)
  29 #       include <boost/mpl/aux_/type_wrapper.hpp>
  30 #   endif
  31 #   else
  32 #       include <boost/mpl/aux_/has_rebind.hpp>
  33 #   endif
  34 #endif
  35
  36 #include <boost/mpl/aux_/config/static_constant.hpp>
  37 #include <boost/mpl/aux_/config/use_preprocessed.hpp>
  38
  39 #if !defined(BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS) \
  40     && !defined(BOOST_MPL_PREPROCESSING_MODE)
  41
  42 #   define BOOST_MPL_PREPROCESSED_HEADER template_arity.hpp
  43 #   include <boost/mpl/aux_/include_preprocessed.hpp>
  44
  45 #else
  46
  47 #   if !defined(BOOST_MPL_CFG_NO_FULL_LAMBDA_SUPPORT)
  48 #   if defined(BOOST_MPL_CFG_EXTENDED_TEMPLATE_PARAMETERS_MATCHING)
  49
  50 #   include <boost/mpl/limits/arity.hpp>
  51 #   include <boost/mpl/aux_/preprocessor/range.hpp>
  52 #   include <boost/mpl/aux_/preprocessor/repeat.hpp>
  53 #   include <boost/mpl/aux_/preprocessor/params.hpp>
  54 #   include <boost/mpl/aux_/nttp_decl.hpp>
  55
  56 #   include <boost/preprocessor/seq/fold_left.hpp>
  57 #   include <boost/preprocessor/comma_if.hpp>
  58 #   include <boost/preprocessor/iterate.hpp>
  59 #   include <boost/preprocessor/inc.hpp>
  60 #   include <boost/preprocessor/cat.hpp>
  61
  62 #   define AUX778076_ARITY BOOST_PP_INC(BOOST_MPL_LIMIT_METAFUNCTION_ARITY)
  63
  64 namespace boost { namespace mpl { namespace aux {
  65
  66 template< BOOST_MPL_AUX_NTTP_DECL(int, N) > struct arity_tag
  67 {
  68     typedef char (&type)[N + 1];
  69 };
  70
  71 #   define AUX778076_MAX_ARITY_OP(unused, state, i_) \
  72     ( BOOST_PP_CAT(C,i_) > 0 ? BOOST_PP_CAT(C,i_) : state ) \
  73 /**/
  74
  75 template<
  76       BOOST_MPL_PP_PARAMS(AUX778076_ARITY, BOOST_MPL_AUX_NTTP_DECL(int, C))
  77     >
  78 struct max_arity
  79 {
  80     BOOST_STATIC_CONSTANT(int, value =
  81           BOOST_PP_SEQ_FOLD_LEFT(
  82               AUX778076_MAX_ARITY_OP
  83             , -1
  84             , BOOST_MPL_PP_RANGE(1, AUX778076_ARITY)
  85             )
  86         );
  87 };
  88
  89 #   undef AUX778076_MAX_ARITY_OP
  90
  91 arity_tag<0>::type arity_helper(...);
  92
  93 #   define BOOST_PP_ITERATION_LIMITS (1, AUX778076_ARITY)
  94 #   define BOOST_PP_FILENAME_1 <boost/mpl/aux_/template_arity.hpp>
  95 #   include BOOST_PP_ITERATE()
  96
  97 template< typename F, BOOST_MPL_AUX_NTTP_DECL(int, N) >
  98 struct template_arity_impl
  99 {
 100     BOOST_STATIC_CONSTANT(int, value =
 101           sizeof(::boost::mpl::aux::arity_helper(type_wrapper<F>(),arity_tag<N>())) - 1
 102         );
 103 };
 104
 105 #   define AUX778076_TEMPLATE_ARITY_IMPL_INVOCATION(unused, i_, F) \
 106     BOOST_PP_COMMA_IF(i_) template_arity_impl<F,BOOST_PP_INC(i_)>::value \
 107 /**/
 108
 109 template< typename F >
 110 struct template_arity
 111 {
 112     BOOST_STATIC_CONSTANT(int, value = (
 113           max_arity< BOOST_MPL_PP_REPEAT(
 114               AUX778076_ARITY
 115             , AUX778076_TEMPLATE_ARITY_IMPL_INVOCATION
 116             , F
 117             ) >::value
 118         ));
 119
 120     typedef mpl::int_<value> type;
 121 };
 122
 123 #   undef AUX778076_TEMPLATE_ARITY_IMPL_INVOCATION
 124
 125 #   undef AUX778076_ARITY
 126
 127 }}}
 128
 129 #   endif // BOOST_MPL_CFG_EXTENDED_TEMPLATE_PARAMETERS_MATCHING
 130 #   else // BOOST_MPL_CFG_NO_FULL_LAMBDA_SUPPORT
 131
 132 #   include <boost/mpl/aux_/config/eti.hpp>
 133
 134 namespace boost { namespace mpl { namespace aux {
 135
 136 template< bool >
 137 struct template_arity_impl
 138 {
 139     template< typename F > struct result_
 140         : mpl::int_<-1>
 141     {
 142     };
 143 };
 144
 145 template<>
 146 struct template_arity_impl<true>
 147 {
 148     template< typename F > struct result_
 149         : F::arity
 150     {
 151     };
 152 };
 153
 154 template< typename F >
 155 struct template_arity
 156     : template_arity_impl< ::boost::mpl::aux::has_rebind<F>::value >
 157         ::template result_<F>
 158 {
 159 };
 160
 161 #if defined(BOOST_MPL_CFG_MSVC_ETI_BUG)
 162 template<>
 163 struct template_arity<int>
 164     : mpl::int_<-1>
 165 {
 166 };
 167 #endif
 168
 169 }}}
 170
 171 #   endif // BOOST_MPL_CFG_NO_FULL_LAMBDA_SUPPORT
 172
 173 #endif // BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS
 174 #endif // BOOST_MPL_AUX_TEMPLATE_ARITY_HPP_INCLUDED
 175
 176 ///// iteration
 177
 178 #else
 179 #define i_ BOOST_PP_FRAME_ITERATION(1)
 180
 181 template<
 182       template< BOOST_MPL_PP_PARAMS(i_, typename P) > class F
 183     , BOOST_MPL_PP_PARAMS(i_, typename T)
 184     >
 185 typename arity_tag<i_>::type
 186 arity_helper(type_wrapper< F<BOOST_MPL_PP_PARAMS(i_, T)> >, arity_tag<i_>);
 187
 188 #undef i_
 189 #endif // BOOST_PP_IS_ITERATING