Re: Supplying an iterator when inserting into vector??

From:

Naresh Rautela <nrautela@gmail.com>

Newsgroups:

comp.lang.c++

Date:

Mon, 04 Jun 2007 16:16:57 -0000

Message-ID:

<1180973817.140896.14680@a26g2000pre.googlegroups.com>

On Jun 4, 8:50 am, desktop <f...@sss.com> wrote:

Naresh Rautela wrote:

On Jun 4, 8:29 am, desktop <f...@sss.com> wrote:

Why does insert only work when specifying an iterator plus the object to
be inserted:

        std::vector<int> t;
        std::vector<int>::iterator it;
        it = t.begin();

        t.insert(it,33);

If I use push_back instead I don't need to supply the iterator. But what
are the reason the insert only works with an iterator?

push_back by default inserts at the end of the container while insert
allows you to mention a position where you can insert.

Ok thanks for the info. When I want to extract an element from the
vector I would use something like:

t.at(0);

But if I have a vector containing my own object that I have defined in a
class 'test' (with a getInt() function returning a private integer) I
would like to use iterators for this:

        std::vector<test*> t2;
        std::vector<test*>::iterator it2;
        it2 = t2.begin();

        test* tt2 = new test(707);
        t2.insert(it2,tt2);
        *it2->getInt()

But this does not work. Are iterators only used for inserting and not
extracting custom objects?- Hide quoted text -

- Show quoted text -

try this

void main()
{
    std::vector<test*> t2;
    std::vector<test*>::iterator it2;
    //it2 = t2.begin();

    test* tt2 = new test(707);
    t2.insert(it2,tt2);
    it2 = t2.begin();
    std::cout << (*it2)->getInt();
}