Standard C++	Library
 		 Copyright 1996, Rogue Wave Software, Inc.

 NAME

   distance_type	 - Determine the type of distance used by an iterator.
   This function is now obsolete.  It	is retained in order to
   provide	backward compatibility and support compilers that
   do not provide  partial specialization.

 SYNOPSIS

   #include <iterator>

   template <class T, class Distance>
   inline Distance* distance_type (const	input_iterator<T,
        Distance>&)

   template <class T, class Distance>
   inline Distance* distance_type (const	forward_iterator<T,
        Distance>&)

   template <class T, class Distance>
   inline Distance*
   distance_type	(const bidirectional_iterator<T, Distance>&)

   template <class T, class Distance>
   inline Distance*
   distance_type	(const random_access_iterator<T, Distance>&)

   template <class T>
   inline ptrdiff_t* distance_type (const T*)

 DESCRIPTION

   The distance_type family of function templates return	a pointer to a
   value that is of the same type as that used	to represent a
   distance	between	two iterators.  The first	four of	these
   take an  iterator of a particular type and return a pointer to a
   default value  of the distance_type for that iterator.  The T* form
   of  the function  returns ptrdiff_t*.

   Generic algorithms use this function to create local variables of
   the correct type.	 The distance_type functions are typically
   used	like this:

   template <class Iterator>
   void foo(Iterator first, Iterator last)
   {
    __foo(begin,end,distance_type(first));
   }

   template <class Iterator, class Distance>
   void __foo(Iterator first,Iterator last, Distance*>
   { Distance d =	Distance();
     distance(first,last,d);
   }

   The auxiliary	function template allows the algorithm to extract a
   distance type from the	first iterator and then	use that type
   to perform some useful work.

 SEE ALSO

   Other	iterator primitives:  value_type, iterator_category, distance,
   advance

 STANDARDS CONFORMANCE
   ANSI X3J16/ISO WG21 Joint C++	Committee