input_iterators (3C++std) - Tru64 UNIX
Standard C++ LibraryCopyright 1996, Rogue Wave Software, Inc. NAME
Input_Iterators - A read-only, forward moving iterator.
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. Input iterators are
read-only, forward moving iterators that satisfy the requirements listed
below.
KEY TO ITERATOR REQUIREMENTS
The following key pertains to the iterator requirement descriptions 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 INPUT ITERATORS
The following expressions must be valid for input iterators:
X u(a) copy constructor, u == a
X u = a assignment, u == a
a == b, a != b return value convertible to bool
*a a == b implies *a == *b
++r returns X&
r++ return value convertible to const X&
*r++ returns type T
a -> m returns (*a).m
For input iterators, a == b does not imply that ++a == ++b.
Algorithms using input iterators should be single pass algorithms. That is
they should not pass through the same iterator twice.
The value of type T does not have to be an lvalue.
SEE ALSO
iterators, output iterators
STANDARDS CONFORMANCE
ANSI X3J16/ISO WG21 Joint C++ Committee
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