Random_Access_Iterators(3C++) - Random_Access_Iterators(3C++)
Standard C++ Library Copyright 1998, Rogue Wave Software, Inc.
NAMERandom_Access_Iterators
- An iterator that reads, writes, and allows random access to a con‐
tainer.
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. Random access itera‐
tors 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 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 RANDOM ACCESS ITERATORS
The following expressions must be valid for random access 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
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 algorithm may make
through the structure.
All relational operators return a value convertible to bool.
SEE ALSO
Iterators, Forward_Iterators, Bidirectional_Iterators
Rogue Wave Software 02 Apr 1998 Random_Access_Iterators(3C++)
