Iterator in loop

sivayella

int main()
{
std::vector<int> vec;
vector<int>::iterator iter;
for (int i = 0 ; i < 5 ; i++)
{
vec.push_back(i+10);
}
for (iter = vec.begin() ; iter != vec.end(); iter++)
{
if (*iter == 12 || *iter == 13)
{
vec.erase(iter);
}
}
for (iter = vec.begin() ; iter != vec.end(); iter++)
{
printf("%d", *iter);
}
return 0;
}

What happens to the iterator when it is incrementedin loop, after erasing 12?

Actually i want to understand the behaviour of the iterator when the element it is pointing to is deleted.

Sep 19 '06 #1

D_C

Straight from the STL documentation

[5] A vector's iterators are invalidated when its memory is reallocated. Additionally, inserting or deleting an element in the middle of a vector invalidates all iterators that point to elements following the insertion or deletion point. It follows that you can prevent a vector's iterators from being invalidated if you use reserve() to preallocate as much memory as the vector will ever use, and if all insertions and deletions are at the vector's end.

Sep 19 '06 #2