question about <list> and pointer to its items

[lallous]

Hello

Given this:

list<mystruct_t> lst;

lst.push_back(item1);
lst.push_back(item2);
lst.push_back(item3);

Now say I have this:

mystruct_t *p1, *p2, *p3 pointing to item1->item3 memory in side the list.

If I delete "item2" (or second item) will the other pointers still be valid?

--
Elias

[John Harrison]

"lallous" <la*****@lgwm.org> wrote in message
news:2t*************@uni-berlin.de...

Hello

Given this:

list<mystruct_t> lst;

lst.push_back(item1);
lst.push_back(item2);
lst.push_back(item3);

Now say I have this:

mystruct_t *p1, *p2, *p3 pointing to item1->item3 memory in side the list.

If I delete "item2" (or second item) will the other pointers still be valid?

If you use iterators instead of pointers (like you should) then the C++
standard guarantees that the iterators will remain valid. I don't know that
the standard guarantees that pointers will be OK, but its very likely to
work.

John

[lallous]

"John Harrison" <jo*************@hotmail.com> wrote in message
news:2t*************@uni-berlin.de...

"lallous" <la*****@lgwm.org> wrote in message
news:2t*************@uni-berlin.de...

Hello

Given this:

list<mystruct_t> lst;

lst.push_back(item1);
lst.push_back(item2);
lst.push_back(item3);

Now say I have this:

mystruct_t *p1, *p2, *p3 pointing to item1->item3 memory in side the
list.

If I delete "item2" (or second item) will the other pointers still be

valid?

If you use iterators instead of pointers (like you should) then the C++
standard guarantees that the iterators will remain valid. I don't know
that
the standard guarantees that pointers will be OK, but its very likely to
work.

You mean I change p1, p2, p3 to:
list<mystruct_t>::iterator p1, p2, p3;

then have p1, p2, p3 point to each element, then when any element is deleted
the other iterators are still valid?

--
Elias

[Sharad Kala]

"John Harrison" <jo*************@hotmail.com> wrote in message

If you use iterators instead of pointers (like you should) then the C++
standard guarantees that the iterators will remain valid.

I think Standard only talks of iterators and references remaining valid, and
am too lazy to check the Standard :-)

Sharad

[John Harrison]

"lallous" <la*****@lgwm.org> wrote in message
news:2t*************@uni-berlin.de...

"John Harrison" <jo*************@hotmail.com> wrote in message
news:2t*************@uni-berlin.de...

"lallous" <la*****@lgwm.org> wrote in message
news:2t*************@uni-berlin.de...

Hello

Given this:

list<mystruct_t> lst;

lst.push_back(item1);
lst.push_back(item2);
lst.push_back(item3);

Now say I have this:

mystruct_t *p1, *p2, *p3 pointing to item1->item3 memory in side the
list.

If I delete "item2" (or second item) will the other pointers still be valid?

If you use iterators instead of pointers (like you should) then the C++
standard guarantees that the iterators will remain valid. I don't know
that
the standard guarantees that pointers will be OK, but its very likely to
work.

You mean I change p1, p2, p3 to:
list<mystruct_t>::iterator p1, p2, p3;

then have p1, p2, p3 point to each element, then when any element is

deleted the other iterators are still valid?

Yes.

john