Dereferencing (pointer to) iterator

[xgngli]

Suppose we have a vector:
vector<intvec(1 0);

We can declare a iterator this way:
vector<int>::it erator vecItor;

and then dereference it like this:
for (vecItor = vec.begin(); vecItor != vec.end(); vecItor++)
{
cout << *vecItor << endl;
}

But how can we dereference the iterator if we declare it this way:
vector<int>::it erator* vecItor;

(I need to declare the iterator the second way since I'm declaring it
under a managed C++ class.)

Thanks!

[Jim Langston]

<xg****@gmail.c omwrote in message
news:11******** *************@c 77g2000hse.goog legroups.com...

> ... (*vecItor)++

and, REALLY, why do you need this nonsense?

You are right. It should be (*vecItor)++ or ++*vecItor. I need to
declare a iterator this way because in a managed C++ class, the
compiler doesn't allow me to declare like this: vector<int>::it erator
vecItor;

Thank you for your help guys!

"Managed" C++ doesn't allow you to:
std::vector<int >::iterator vecItor;
??? I would chuck that piece of garbage so far out the window it would
leave orbit.

[=?ISO-8859-1?Q?Erik_Wikstr=F6m?=]

On 2007-06-24 09:11, Jim Langston wrote:

<xg****@gmail.c omwrote in message
news:11******** *************@c 77g2000hse.goog legroups.com...

>> ... (*vecItor)++

and, REALLY, why do you need this nonsense?

You are right. It should be (*vecItor)++ or ++*vecItor. I need to
declare a iterator this way because in a managed C++ class, the
compiler doesn't allow me to declare like this: vector<int>::it erator
vecItor;

Thank you for your help guys!

"Managed" C++ doesn't allow you to:
std::vector<int >::iterator vecItor;
??? I would chuck that piece of garbage so far out the window it would
leave orbit.

It would, but as soon as you start playing with the classes from the
..Net framework (and why use C++/CLR if you don't?) you'll be using
managed classes and they usually don't play well on the stack, so
there'll be lots of List<intl = gcnew List<int>(); all over the place.

--
Erik Wikström

[James Kanze]

On Jun 22, 11:55 pm, "xgn...@gmail.c om" <xgn...@gmail.c omwrote:

Suppose we have a vector:
vector<intvec(1 0);

We can declare a iterator this way:
vector<int>::it erator vecItor;

Modulo using a typedef, that's the only way to declare an
iterator.

and then dereference it like this:
for (vecItor = vec.begin(); vecItor != vec.end(); vecItor++)
{
cout << *vecItor << endl;
}

But how can we dereference the iterator if we declare it this way:
vector<int>::it erator* vecItor;

That doesn't declare an iterator. It declares a pointer to an
iterator. Given that iterators have value semantics in C++, and
generally are designed to have short and restricted livetimes
(since various modifications to the underlying container can
invalidate them), it's hard to see where this would be
appropriate. Do you really want to have to write things like:

std::vector< int >::iterator* i
= new std::vector< int >::iterator( vec.begin() ) ;
while ( *i != vec.end() ) {
// ...
delete i ;

(I need to declare the iterator the second way since I'm declaring it
under a managed C++ class.)

Ask in a group about managed C++. I'm not familiar with it, but
I don't think that they would have C++ in the name if it didn't
support value types.

--
James Kanze (Gabi Software) email: ja*********@gma il.com
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