Bidirectional_Iterators(3C++) - Bidirectional_Iterators(3C++)
Standard C++ Library Copyright 1998, Rogue Wave Software, Inc.
NAMEBidirectional_Iterators
- An iterator that can both read and write and can traverse a con‐
tainer in both directions
DESCRIPTION
NOTE:
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. Bidirectional itera‐
tors can move both forwards and backwards through a container, 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 descriptions listed below:
a and b values of type X
n value representing a distance between two iterators
u, Distance, tmp and m identifiers
r value of type X&
t value of type T
REQUIREMENTS FOR BIDIRECTIONAL ITERATORS
A bidirectional iterator must meet all the requirements listed below.
Note that most of these requirements are also the requirements for for‐
ward 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
r = a assignment, r == a
a == b, a != b return value convertible to bool
a->m equivalent to (*a).m
*a return value convertible to T&
++r returns X&
r++ return value convertible to const X&
*r++ returns T&
--r returns X&
r-- return value convertible to const X&
*r-- returns T&
Like forward iterators, bidirectional 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
Containers, Iterators, Forward_Iterators
Rogue Wave Software 02 Apr 1998 Bidirectional_Iterators(3C++)