random_access_iterators (3C++std) - Tru64 UNIX
Standard C++ LibraryCopyright 1996, Rogue Wave Software, Inc.
NAME
Random_Access_Iterators - An iterator that reads and writes, and provides
random access to a container.
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. Random access iterators
can read and write, and provide 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
*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
STANDARDS CONFORMANCE
ANSI X3J16/ISO WG21 Joint C++ Committee
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