include/functionInfo.h

   1 /***************************************************************************
   2  *   This file is part of KWorship.                                        *
   3  *   Copyright 2008 James Hogan <james@albanarts.com>                      *
   4  *                                                                         *
   5  *   KWorship is free software: you can redistribute it and/or modify      *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation, either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   KWorship is distributed in the hope that it will be useful,           *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15  *   You should have received a copy of the GNU General Public License     *
  16  *   along with KWorship.  If not, write to the Free Software Foundation,  *
  17  *   Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.   *
  18  ***************************************************************************/
  19
  20 #ifndef _functionInfo_h_
  21 #define _functionInfo_h_
  22
  23 #include "repeatMacros.h"
  24
  25 namespace meta
  26 {
  27   // Pointer handling
  28   template <typename T>
  29   struct PointerInfo;
  30
  31   template <typename T>
  32   struct PointerInfo<T*>
  33   {
  34     typedef T Type;
  35   };
  36
  37   template <typename F>
  38   struct Tuple;
  39 #define META_TUPLE(ARGS) ::meta::Tuple<void (*)ARGS>
  40
  41   template <typename F, int P>
  42   struct ParameterInfo;
  43
  44   // Number of arguments of a function
  45   template <typename F>
  46   struct FunctionInfo;
  47
  48
  49   // Macros to make this easier
  50
  51   // Parameter list, e.g. "typename Param0; typename Param1;"
  52 #define FUNCTION_INFO_PARAM_INSTANTIATION(A,B,N)  Param##N param##N;
  53 #define FUNCTION_INFO_PARAM_INSTANTIATIONS(N) REPEATB(FUNCTION_INFO_PARAM_INSTANTIATION,0,0,N)
  54   // Parameter list, e.g. "typename Param0, typename Param1"
  55 #define FUNCTION_INFO_TEMPLATE_PARAMETER(A,B,N)  typename Param##N
  56 #define FUNCTION_INFO_TEMPLATE_PARAMETERS(N) REPEATB_LIST(FUNCTION_INFO_TEMPLATE_PARAMETER,0,0,N)
  57   // Parameter list, e.g. ", typename Param0, typename Param1"
  58 #define FUNCTION_INFO_TEMPLATE_PARAMETER_TAIL(A,B,N)  , typename Param##N
  59 #define FUNCTION_INFO_TEMPLATE_PARAMETERS_TAIL(N) REPEATB(FUNCTION_INFO_TEMPLATE_PARAMETER_TAIL,0,0,N)
  60   // Argument list, e.g. "(Param0 param0, Param1 param1)"
  61 #define FUNCTION_INFO_PARAMETER(A,B,N)   Param##N param##N
  62 #define FUNCTION_INFO_PARAMETERS(N) \
  63   ( REPEATB_LIST(FUNCTION_INFO_PARAMETER,0,0,N) )
  64   // Tail argument list, e.g. ", Param0, Param1"
  65 #define FUNCTION_INFO_PARAMETER_TAIL(A,B,N) , Param##N
  66 #define FUNCTION_INFO_PARAMETERS_TAIL(N) \
  67   REPEATB(FUNCTION_INFO_PARAMETER_TAIL,0,0,N)
  68   // Argument list, e.g. "(param0, param1)"
  69 #define FUNCTION_INFO_ARGUMENT(A,B,N)   param##N
  70 #define FUNCTION_INFO_ARGUMENTS(N) \
  71   ( REPEATB_LIST(FUNCTION_INFO_ARGUMENT,0,0,N) )
  72   // Unpack Argument list, e.g. "(P.param0, P.param1)"
  73 #define FUNCTION_INFO_UNPACK_ARGUMENT(P,B,N)   (P).param##N
  74 #define FUNCTION_INFO_UNPACK_ARGUMENTS(P,N) \
  75   ( REPEATB_LIST(FUNCTION_INFO_UNPACK_ARGUMENT,P,0,N) )
  76   // Unpack Argument list with preceding comma, e.g. ", P.param0, P.param1"
  77 #define FUNCTION_INFO_UNPACK_ARGUMENT_PRECOMMA(P,B,N)   , (P).param##N
  78 #define FUNCTION_INFO_UNPACK_ARGUMENTS_PRECOMMA(P,N) \
  79   REPEATB(FUNCTION_INFO_UNPACK_ARGUMENT_PRECOMMA,P,0,N)
  80
  81   // Parameter template instantiation
  82 #define PARAMETER_INFO(T,N) \
  83   template <typename R, FUNCTION_INFO_TEMPLATE_PARAMETERS(T) > \
  84   struct ParameterInfo<R (*)FUNCTION_INFO_PARAMETERS(T),N> \
  85   { \
  86     typedef Param##N Type; \
  87   };
  88
  89   // Function length template instantiation
  90 #define FUNCTION_INFO(N) \
  91   template <FUNCTION_INFO_TEMPLATE_PARAMETERS(N) > \
  92   struct Tuple<void (*)FUNCTION_INFO_PARAMETERS(N)> \
  93   { \
  94     enum \
  95     { \
  96       length = N \
  97     }; \
  98     struct Pack \
  99     { \
 100       /* A member for each item */ \
 101       FUNCTION_INFO_PARAM_INSTANTIATIONS(N) \
 102       /* Construct a new CTYPE using the pack as arguments */ \
 103       template <typename CTYPE> \
 104       CTYPE* construct() const \
 105       { \
 106         return new CTYPE FUNCTION_INFO_ARGUMENTS(N); \
 107       } \
 108     }; \
 109     static struct Pack pack FUNCTION_INFO_PARAMETERS(N) \
 110     { \
 111       Pack myPack = { REPEATB_LIST(FUNCTION_INFO_ARGUMENT,0,0,N) }; \
 112       return myPack; \
 113     } \
 114     template <int id> \
 115     struct Param : public ParameterInfo<void (*)FUNCTION_INFO_PARAMETERS(N), id> \
 116     { \
 117     }; \
 118     template <typename Ret> \
 119     struct Return \
 120     { \
 121       typedef Ret (Signiture)FUNCTION_INFO_PARAMETERS(N); \
 122       typedef Ret (*Pointer)FUNCTION_INFO_PARAMETERS(N); \
 123       typedef FunctionInfo<Pointer> Info; \
 124     }; \
 125     template <typename NewArg> \
 126     struct Unshift \
 127     { \
 128       typedef void (*Pointer)(NewArg FUNCTION_INFO_PARAMETERS_TAIL(N)); \
 129       typedef Tuple<Pointer> Info; \
 130     }; \
 131   }; \
 132   template <typename Ret FUNCTION_INFO_TEMPLATE_PARAMETERS_TAIL(N) > \
 133   struct FunctionInfo<Ret (*)FUNCTION_INFO_PARAMETERS(N)> \
 134   { \
 135     typedef Ret Return; \
 136     typedef Ret (*Pointer)FUNCTION_INFO_PARAMETERS(N); \
 137     typedef Tuple<void (*)FUNCTION_INFO_PARAMETERS(N)> Params; \
 138     template <typename NewArg> \
 139     struct Unshift \
 140     { \
 141       typedef Ret (*Pointer)(NewArg FUNCTION_INFO_PARAMETERS_TAIL(N)); \
 142       typedef FunctionInfo<Pointer> Info; \
 143     }; \
 144     template <typename FUNCTOR> \
 145     static Ret unpack(typename Params::Pack package) \
 146     { \
 147       return FUNCTOR::call FUNCTION_INFO_UNPACK_ARGUMENTS(package,N); \
 148     } \
 149     template <typename FUNCTOR, typename P0> \
 150     static Ret unpack(P0 p0, typename Params::Pack package) \
 151     { \
 152       return FUNCTOR::call ( p0 FUNCTION_INFO_UNPACK_ARGUMENTS_PRECOMMA(package,N) ); \
 153     } \
 154     /* Call a pointer with a pack of arguments */ \
 155     static Ret call(Pointer f, typename Params::Pack package) \
 156     { \
 157       return f FUNCTION_INFO_UNPACK_ARGUMENTS(package,N); \
 158     } \
 159     /* Call a pointer with one plus a pack of arguments */ \
 160     template <typename P0> \
 161     static Ret call(typename Unshift<P0>::Pointer f, P0 p0, typename Params::Pack package) \
 162     { \
 163       return f( p0 FUNCTION_INFO_UNPACK_ARGUMENTS_PRECOMMA(package,N) ); \
 164     } \
 165   }; \
 166   REPEATA(PARAMETER_INFO, N, N)
 167
 168
 169   REPEAT(FUNCTION_INFO, 8)
 170
 171 #undef FUNCTION_INFO_PARAMETER
 172 #undef FUNCTION_INFO_PARAMETERS
 173 #undef FUNCTION_INFO_ARGUMENT
 174 #undef FUNCTION_INFO_POINTER_TYPE
 175 #undef PARAMETER_INFO
 176 #undef FUNCTION_INFO
 177 }
 178
 179 #endif // _functionInfo_h_
 180