

//  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.



#ifndef BOOST_TT_FUNCTION_TRAITS_HPP_INCLUDED

#define BOOST_TT_FUNCTION_TRAITS_HPP_INCLUDED



#include <boost/config.hpp>

#include <boost/type_traits/is_function.hpp>

#include <boost/type_traits/add_pointer.hpp>



namespace boost {



#ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

namespace detail {



template<typename Function> struct function_traits_helper;



template<typename R>

struct function_traits_helper<R (*)(void)>

{

  BOOST_STATIC_CONSTANT(unsigned, arity = 0);

  typedef R result_type;

};



template<typename R, typename T1>

struct function_traits_helper<R (*)(T1)>

{

  BOOST_STATIC_CONSTANT(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)>

{

  BOOST_STATIC_CONSTANT(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)>

{

  BOOST_STATIC_CONSTANT(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)>

{

  BOOST_STATIC_CONSTANT(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)>

{

  BOOST_STATIC_CONSTANT(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)>

{

  BOOST_STATIC_CONSTANT(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)>

{

  BOOST_STATIC_CONSTANT(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)>

{

  BOOST_STATIC_CONSTANT(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)>

{

  BOOST_STATIC_CONSTANT(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)>

{

  BOOST_STATIC_CONSTANT(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 detail::function_traits_helper<typename boost::add_pointer<Function>::type>

{

};



#else



namespace detail {



template<unsigned N> 

struct type_of_size

{

  char elements[N];

};



template<typename R>

type_of_size<1> function_arity_helper(R (*f)());



template<typename R, typename T1>

type_of_size<2> function_arity_helper(R (*f)(T1));



template<typename R, typename T1, typename T2>

type_of_size<3> function_arity_helper(R (*f)(T1, T2));



template<typename R, typename T1, typename T2, typename T3>

type_of_size<4> function_arity_helper(R (*f)(T1, T2, T3));



template<typename R, typename T1, typename T2, typename T3, typename T4>

type_of_size<5> function_arity_helper(R (*f)(T1, T2, T3, T4));



template<typename R, typename T1, typename T2, typename T3, typename T4,

         typename T5>

type_of_size<6> function_arity_helper(R (*f)(T1, T2, T3, T4, T5));



template<typename R, typename T1, typename T2, typename T3, typename T4,

         typename T5, typename T6>

type_of_size<7> function_arity_helper(R (*f)(T1, T2, T3, T4, T5, T6));



template<typename R, typename T1, typename T2, typename T3, typename T4,

         typename T5, typename T6, typename T7>

type_of_size<8> function_arity_helper(R (*f)(T1, T2, T3, T4, T5, T6, T7));



template<typename R, typename T1, typename T2, typename T3, typename T4,

         typename T5, typename T6, typename T7, typename T8>

type_of_size<9> function_arity_helper(R (*f)(T1, T2, T3, T4, T5, T6, T7, T8));



template<typename R, typename T1, typename T2, typename T3, typename T4,

         typename T5, typename T6, typename T7, typename T8, typename T9>

type_of_size<10> function_arity_helper(R (*f)(T1, T2, T3, T4, T5, T6, T7, T8, 

                                              T9));



template<typename R, typename T1, typename T2, typename T3, typename T4,

         typename T5, typename T6, typename T7, typename T8, typename T9,

         typename T10>

type_of_size<11> function_arity_helper(R (*f)(T1, T2, T3, T4, T5, T6, T7, T8, 

                                              T9, T10));

} // end namespace detail



// Won't work with references

template<typename Function>

struct function_traits

{

  BOOST_STATIC_CONSTANT(unsigned, arity = (sizeof(detail::function_arity_helper((Function*)0))-1));

};



#endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION

}



#endif // BOOST_TT_FUNCTION_TRAITS_HPP_INCLUDED

