On Mon, 19 Jul 2010 17:54:59 -0400, Mafi <m...@example.org> wrote:
I have to say that I'm not a specialist in STL or C++ in general but as
far as I know an iterator is class mainly consisting of a pointer to the
container, the current index and the operator-overloadd-function for ++.
So what can you do with a iterator that you can't do with
KeyType delegate(KeyType,Container /* which is indexed by KeyType */)
No, an iterator is a pointer to an *element* in the container. The lookup
is a simple dereference, not an indexing operation. They even work on
containers that don't support indexing.
The benefit of iterators is speed of lookup and reference to a single
element. Ranges represent a pair of iterators, with the benefit that they
are always properly ordered and are related. Many STL functions accept 2
iterators but are undefined if the two iterators are not related or
ordered properly. Ranges have a huge benefit over iterators for this, and
most of STL's algorithm is based on pairs of iterators. However, ranges
generally refer to *two* elements, a begin and an end element. This has
some disadvantages when you want to only refer to one element.
-Steve
