boost/type_traits/function_traits.hpp

   1
   2 //  Copyright 2000 John Maddock (john@johnmaddock.co.uk)
   3 //  Use, modification and distribution are subject to the Boost Software License,
   4 //  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   5 //  http://www.boost.org/LICENSE_1_0.txt).
   6 //
   7 //  See http://www.boost.org/libs/type_traits for most recent version including documentation.
   8
   9 #ifndef BOOST_TT_FUNCTION_TRAITS_HPP_INCLUDED
  10 #define BOOST_TT_FUNCTION_TRAITS_HPP_INCLUDED
  11
  12 #include <boost/config.hpp>
  13 #include <boost/type_traits/is_function.hpp>
  14 #include <boost/type_traits/add_pointer.hpp>
  15
  16 namespace boost {
  17
  18 #ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
  19 namespace detail {
  20
  21 template<typename Function> struct function_traits_helper;
  22
  23 template<typename R>
  24 struct function_traits_helper<R (*)(void)>
  25 {
  26   BOOST_STATIC_CONSTANT(unsigned, arity = 0);
  27   typedef R result_type;
  28 };
  29
  30 template<typename R, typename T1>
  31 struct function_traits_helper<R (*)(T1)>
  32 {
  33   BOOST_STATIC_CONSTANT(unsigned, arity = 1);
  34   typedef R result_type;
  35   typedef T1 arg1_type;
  36   typedef T1 argument_type;
  37 };
  38
  39 template<typename R, typename T1, typename T2>
  40 struct function_traits_helper<R (*)(T1, T2)>
  41 {
  42   BOOST_STATIC_CONSTANT(unsigned, arity = 2);
  43   typedef R result_type;
  44   typedef T1 arg1_type;
  45   typedef T2 arg2_type;
  46   typedef T1 first_argument_type;
  47   typedef T2 second_argument_type;
  48 };
  49
  50 template<typename R, typename T1, typename T2, typename T3>
  51 struct function_traits_helper<R (*)(T1, T2, T3)>
  52 {
  53   BOOST_STATIC_CONSTANT(unsigned, arity = 3);
  54   typedef R result_type;
  55   typedef T1 arg1_type;
  56   typedef T2 arg2_type;
  57   typedef T3 arg3_type;
  58 };
  59
  60 template<typename R, typename T1, typename T2, typename T3, typename T4>
  61 struct function_traits_helper<R (*)(T1, T2, T3, T4)>
  62 {
  63   BOOST_STATIC_CONSTANT(unsigned, arity = 4);
  64   typedef R result_type;
  65   typedef T1 arg1_type;
  66   typedef T2 arg2_type;
  67   typedef T3 arg3_type;
  68   typedef T4 arg4_type;
  69 };
  70
  71 template<typename R, typename T1, typename T2, typename T3, typename T4,
  72          typename T5>
  73 struct function_traits_helper<R (*)(T1, T2, T3, T4, T5)>
  74 {
  75   BOOST_STATIC_CONSTANT(unsigned, arity = 5);
  76   typedef R result_type;
  77   typedef T1 arg1_type;
  78   typedef T2 arg2_type;
  79   typedef T3 arg3_type;
  80   typedef T4 arg4_type;
  81   typedef T5 arg5_type;
  82 };
  83
  84 template<typename R, typename T1, typename T2, typename T3, typename T4,
  85          typename T5, typename T6>
  86 struct function_traits_helper<R (*)(T1, T2, T3, T4, T5, T6)>
  87 {
  88   BOOST_STATIC_CONSTANT(unsigned, arity = 6);
  89   typedef R result_type;
  90   typedef T1 arg1_type;
  91   typedef T2 arg2_type;
  92   typedef T3 arg3_type;
  93   typedef T4 arg4_type;
  94   typedef T5 arg5_type;
  95   typedef T6 arg6_type;
  96 };
  97
  98 template<typename R, typename T1, typename T2, typename T3, typename T4,
  99          typename T5, typename T6, typename T7>
 100 struct function_traits_helper<R (*)(T1, T2, T3, T4, T5, T6, T7)>
 101 {
 102   BOOST_STATIC_CONSTANT(unsigned, arity = 7);
 103   typedef R result_type;
 104   typedef T1 arg1_type;
 105   typedef T2 arg2_type;
 106   typedef T3 arg3_type;
 107   typedef T4 arg4_type;
 108   typedef T5 arg5_type;
 109   typedef T6 arg6_type;
 110   typedef T7 arg7_type;
 111 };
 112
 113 template<typename R, typename T1, typename T2, typename T3, typename T4,
 114          typename T5, typename T6, typename T7, typename T8>
 115 struct function_traits_helper<R (*)(T1, T2, T3, T4, T5, T6, T7, T8)>
 116 {
 117   BOOST_STATIC_CONSTANT(unsigned, arity = 8);
 118   typedef R result_type;
 119   typedef T1 arg1_type;
 120   typedef T2 arg2_type;
 121   typedef T3 arg3_type;
 122   typedef T4 arg4_type;
 123   typedef T5 arg5_type;
 124   typedef T6 arg6_type;
 125   typedef T7 arg7_type;
 126   typedef T8 arg8_type;
 127 };
 128
 129 template<typename R, typename T1, typename T2, typename T3, typename T4,
 130          typename T5, typename T6, typename T7, typename T8, typename T9>
 131 struct function_traits_helper<R (*)(T1, T2, T3, T4, T5, T6, T7, T8, T9)>
 132 {
 133   BOOST_STATIC_CONSTANT(unsigned, arity = 9);
 134   typedef R result_type;
 135   typedef T1 arg1_type;
 136   typedef T2 arg2_type;
 137   typedef T3 arg3_type;
 138   typedef T4 arg4_type;
 139   typedef T5 arg5_type;
 140   typedef T6 arg6_type;
 141   typedef T7 arg7_type;
 142   typedef T8 arg8_type;
 143   typedef T9 arg9_type;
 144 };
 145
 146 template<typename R, typename T1, typename T2, typename T3, typename T4,
 147          typename T5, typename T6, typename T7, typename T8, typename T9,
 148          typename T10>
 149 struct function_traits_helper<R (*)(T1, T2, T3, T4, T5, T6, T7, T8, T9, T10)>
 150 {
 151   BOOST_STATIC_CONSTANT(unsigned, arity = 10);
 152   typedef R result_type;
 153   typedef T1 arg1_type;
 154   typedef T2 arg2_type;
 155   typedef T3 arg3_type;
 156   typedef T4 arg4_type;
 157   typedef T5 arg5_type;
 158   typedef T6 arg6_type;
 159   typedef T7 arg7_type;
 160   typedef T8 arg8_type;
 161   typedef T9 arg9_type;
 162   typedef T10 arg10_type;
 163 };
 164
 165 } // end namespace detail
 166
 167 template<typename Function>
 168 struct function_traits :
 169    public detail::function_traits_helper<typename boost::add_pointer<Function>::type>
 170 {
 171 };
 172
 173 #else
 174
 175 namespace detail {
 176
 177 template<unsigned N>
 178 struct type_of_size
 179 {
 180   char elements[N];
 181 };
 182
 183 template<typename R>
 184 type_of_size<1> function_arity_helper(R (*f)());
 185
 186 template<typename R, typename T1>
 187 type_of_size<2> function_arity_helper(R (*f)(T1));
 188
 189 template<typename R, typename T1, typename T2>
 190 type_of_size<3> function_arity_helper(R (*f)(T1, T2));
 191
 192 template<typename R, typename T1, typename T2, typename T3>
 193 type_of_size<4> function_arity_helper(R (*f)(T1, T2, T3));
 194
 195 template<typename R, typename T1, typename T2, typename T3, typename T4>
 196 type_of_size<5> function_arity_helper(R (*f)(T1, T2, T3, T4));
 197
 198 template<typename R, typename T1, typename T2, typename T3, typename T4,
 199          typename T5>
 200 type_of_size<6> function_arity_helper(R (*f)(T1, T2, T3, T4, T5));
 201
 202 template<typename R, typename T1, typename T2, typename T3, typename T4,
 203          typename T5, typename T6>
 204 type_of_size<7> function_arity_helper(R (*f)(T1, T2, T3, T4, T5, T6));
 205
 206 template<typename R, typename T1, typename T2, typename T3, typename T4,
 207          typename T5, typename T6, typename T7>
 208 type_of_size<8> function_arity_helper(R (*f)(T1, T2, T3, T4, T5, T6, T7));
 209
 210 template<typename R, typename T1, typename T2, typename T3, typename T4,
 211          typename T5, typename T6, typename T7, typename T8>
 212 type_of_size<9> function_arity_helper(R (*f)(T1, T2, T3, T4, T5, T6, T7, T8));
 213
 214 template<typename R, typename T1, typename T2, typename T3, typename T4,
 215          typename T5, typename T6, typename T7, typename T8, typename T9>
 216 type_of_size<10> function_arity_helper(R (*f)(T1, T2, T3, T4, T5, T6, T7, T8,
 217                                               T9));
 218
 219 template<typename R, typename T1, typename T2, typename T3, typename T4,
 220          typename T5, typename T6, typename T7, typename T8, typename T9,
 221          typename T10>
 222 type_of_size<11> function_arity_helper(R (*f)(T1, T2, T3, T4, T5, T6, T7, T8,
 223                                               T9, T10));
 224 } // end namespace detail
 225
 226 // Won't work with references
 227 template<typename Function>
 228 struct function_traits
 229 {
 230   BOOST_STATIC_CONSTANT(unsigned, arity = (sizeof(detail::function_arity_helper((Function*)0))-1));
 231 };
 232
 233 #endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
 234 }
 235
 236 #endif // BOOST_TT_FUNCTION_TRAITS_HPP_INCLUDED