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Input Iterators
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Input Iterators
Iterator
- Summary
- Data Type and Member Function Indexes
- Description
- Key to Iterator Requirements
- Requirements for Input Iterators
- See Also
Summary
A read-only, forward moving iterator.
Data Type and Member Function Indexes
(exclusive of constructors and destructors)
None
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
©Copyright 1996, Rogue Wave Software, Inc.
