Standard C++ Library
Copyright 1998, Rogue Wave Software, Inc.
- An iterator that reads, writes, and allows random access
to a container.
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 struc-
tures. Random access iterators can read, write, and allow
random access to the containers they serve. These iterators
satisfy the requirements listed below.
KEY TO ITERATOR REQUIREMENTS
The following key pertains to the iterator requirements
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 RANDOM ACCESS ITERATORS
The following expressions must be valid for random access
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
r = a assignment, r == a
*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&
--r returns X&
r-- return value convertible to const X&
*r-- returns T&
r += n Semantics of --r or ++r n times depending on the
sign of n
a + n, n + a returns type X
r -= n returns X&, behaves as r += -n
a - n returns type X
b - a returns distance
a[n] *(a+n), return value convertible to T
a < b total ordering relation
a > b total ordering relation opposite to <
a <= b !(a < b)
a >= b !(a > b)
Like forward iterators, random access iterators have the
condition that a == b implies *a == *b.
There are no restrictions on the number of passes an algo-
rithm may make through the structure.
All relational operators return a value convertible to bool.
Iterators, Forward_Iterators, Bidirectional_Iterators