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

 NAME

   Forward_Iterators  - A forward-moving	iterator that can both read
   and write.

 DESCRIPTION

   For a	complete discussion of iterators, see the Iterators section of
   this reference.

   Iterators are	a generalization of pointers that allow	a C++ program
   to uniformly interact with different data structures.  Forward
   iterators are forward moving, and have	the ability to both
   read and write data.  These iterators satisfy the	requirements
   listed below.

 KEY TO ITERATOR	REQUIREMENTS

   The following	key pertains to	the iterator requirements listed below:

   a and	b   values of type X

   n   value of distance	type

   u, Distance, tmp and m   identifiers

   r   value of type X&

   t   value of type T

 REQUIREMENTS FOR FORWARD ITERATORS

   The following	expressions must be valid for forward iterators:

   X u	u might	have a singular	value

   X()	X() might be singular

   X(a)	 copy constructor, a ==	X(a).

   X u(a)   copy	constructor, u == a

   X u =	a   assignment,	u == a

   a == b, a != b   return value	convertible to bool

   *a   return value convertible	to T&

   a->m	 equivalent to (*a).m

   ++r	returns	X&

   r++	return value convertible to const X&

   *r++	 returns T&

   Forward iterators have the condition that a == b implies *a == *b.

   There	are no restrictions on the number of passes an algorithm may
   make through the structure.

 SEE ALSO

   Iterators, Bidirectional Iterators

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