Re: Can iterator be checked to be at end of vector?
On Jul 30, 3:57 pm, Michael Doubez <michael.dou...@free.fr> wrote:
On 30 juil, 14:59, Pete Becker <p...@versatilecoding.com> wrote:
[...]
Iterators aren't based on containers. That's looking at it
the wrong way around. Sequences are the fundamental notion
in STL. A pair of iterators specifies a range of objects
within a sequence. Containers are one way to create
sequences, but not the only way.
What is misleading is that:
- the Iterator pattern of the GoF book is described as a way "to
access the elements of an aggregate object sequentially"
Which is the most frequent use.
- the Iterator concept of the STL (SGI) "Iterators are a
generalization of pointers: they are objects that point to other
objects."
The problem with the STL here is that they've hijacked the name
of another concept. So whenever you speak about iterators in
C++, you have to say whether you mean what is meant be iterator
in general, or in the context of the standard library.
In OOP case, it can make sense to keep a reference to the
container in order to stop the iteration ( prev()/next() and
done() methods).
Not a reference to the container, but an end iterator. Or use
GoF iterators.
--
James Kanze (GABI Software) email:james.kanze@gmail.com
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