text: //  Copyright 2000 John Maddock (john@johnmaddock.co.uk)
  //  Use, modification and distribution are subject to the Boost Software License,
  //  Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
  //  http://www.boost.org/LICENSE_1_0.txt).
  //
  //  See http://www.boost.org/libs/type_traits for most recent version including documentation.
  
  #pragma once
  
  #include <type_traits>
  
  namespace multi_index {
  namespace detail {
  
  template<typename Function> struct function_traits_helper;
  
  template<typename R>
  struct function_traits_helper<R (*)(void)>
  {
    static const unsigned arity = 0;
    typedef R result_type;
  };
  
  template<typename R, typename T1>
  struct function_traits_helper<R (*)(T1)>
  {
    static const unsigned arity = 1;
    typedef R result_type;
    typedef T1 arg1_type;
    typedef T1 argument_type;
  };
  
  template<typename R, typename T1, typename T2>
  struct function_traits_helper<R (*)(T1, T2)>
  {
    static const unsigned arity = 2;
    typedef R result_type;
    typedef T1 arg1_type;
    typedef T2 arg2_type;
    typedef T1 first_argument_type;
    typedef T2 second_argument_type;
  };
  
  template<typename R, typename T1, typename T2, typename T3>
  struct function_traits_helper<R (*)(T1, T2, T3)>
  {
    static const unsigned arity = 3;
    typedef R result_type;
    typedef T1 arg1_type;
    typedef T2 arg2_type;
    typedef T3 arg3_type;
  };
  
  template<typename R, typename T1, typename T2, typename T3, typename T4>
  struct function_traits_helper<R (*)(T1, T2, T3, T4)>
  {
    static const unsigned arity = 4;
    typedef R result_type;
    typedef T1 arg1_type;
    typedef T2 arg2_type;
    typedef T3 arg3_type;
    typedef T4 arg4_type;
  };
  
  template<typename R, typename T1, typename T2, typename T3, typename T4,
           typename T5>
  struct function_traits_helper<R (*)(T1, T2, T3, T4, T5)>
  {
    static const unsigned arity = 5;
    typedef R result_type;
    typedef T1 arg1_type;
    typedef T2 arg2_type;
    typedef T3 arg3_type;
    typedef T4 arg4_type;
    typedef T5 arg5_type;
  };
  
  template<typename R, typename T1, typename T2, typename T3, typename T4,
           typename T5, typename T6>
  struct function_traits_helper<R (*)(T1, T2, T3, T4, T5, T6)>
  {
    static const unsigned arity = 6;
    typedef R result_type;
    typedef T1 arg1_type;
    typedef T2 arg2_type;
    typedef T3 arg3_type;
    typedef T4 arg4_type;
    typedef T5 arg5_type;
    typedef T6 arg6_type;
  };
  
  template<typename R, typename T1, typename T2, typename T3, typename T4,
           typename T5, typename T6, typename T7>
  struct function_traits_helper<R (*)(T1, T2, T3, T4, T5, T6, T7)>
  {
    static const unsigned arity = 7;
    typedef R result_type;
    typedef T1 arg1_type;
    typedef T2 arg2_type;
    typedef T3 arg3_type;
    typedef T4 arg4_type;
    typedef T5 arg5_type;
    typedef T6 arg6_type;
    typedef T7 arg7_type;
  };
  
  template<typename R, typename T1, typename T2, typename T3, typename T4,
           typename T5, typename T6, typename T7, typename T8>
  struct function_traits_helper<R (*)(T1, T2, T3, T4, T5, T6, T7, T8)>
  {
    static const unsigned arity = 8;
    typedef R result_type;
    typedef T1 arg1_type;
    typedef T2 arg2_type;
    typedef T3 arg3_type;
    typedef T4 arg4_type;
    typedef T5 arg5_type;
    typedef T6 arg6_type;
    typedef T7 arg7_type;
    typedef T8 arg8_type;
  };
  
  template<typename R, typename T1, typename T2, typename T3, typename T4,
           typename T5, typename T6, typename T7, typename T8, typename T9>
  struct function_traits_helper<R (*)(T1, T2, T3, T4, T5, T6, T7, T8, T9)>
  {
    static const unsigned arity = 9;
    typedef R result_type;
    typedef T1 arg1_type;
    typedef T2 arg2_type;
    typedef T3 arg3_type;
    typedef T4 arg4_type;
    typedef T5 arg5_type;
    typedef T6 arg6_type;
    typedef T7 arg7_type;
    typedef T8 arg8_type;
    typedef T9 arg9_type;
  };
  
  template<typename R, typename T1, typename T2, typename T3, typename T4,
           typename T5, typename T6, typename T7, typename T8, typename T9,
           typename T10>
  struct function_traits_helper<R (*)(T1, T2, T3, T4, T5, T6, T7, T8, T9, T10)>
  {
    static const unsigned arity = 10;
    typedef R result_type;
    typedef T1 arg1_type;
    typedef T2 arg2_type;
    typedef T3 arg3_type;
    typedef T4 arg4_type;
    typedef T5 arg5_type;
    typedef T6 arg6_type;
    typedef T7 arg7_type;
    typedef T8 arg8_type;
    typedef T9 arg9_type;
    typedef T10 arg10_type;
  };
  
  } // end namespace detail
  
  template<typename Function>
  struct function_traits :
    public multi_index::detail::function_traits_helper<typename std::add_pointer<Function>::type>
  {
  };
  
  } // multi_index
  