Why is this vector iterator not incrementable?

Question

I\'m trying to delete the vector\'s content and I\'m getting an error - vector iterator is not incrementable, why is that?

This is my destructor:

C         


        

Answer 1

Vector iterators are incrementable, but if you delete elements, the vector contents are modified and thus the iterator is invalid.

So, if you delete objects, you should use the return value of erase() that gives you the next valid iterator.

Answer 2

This is not relevant to the original problem posted above, but Google search on the error takes me to this page so I am posting it here for anyone to see.

I ran into this error message recently and all lines of codes checked out (there was no 'erase' or anything alike; the vector was merely read).

Eventually, I realized that there is a problem with nested loops.

For example, consider something like this:

`for (it=begin(); it!=end();i++)
{
    for (; it!=end();i++)
    {
    }
}`

When you are done with the nested loop, it will increment the iterator - and then, the parent loop will increment it again(!), ultimately making the iterator step over the end(). I.e. it would be "end()+1" if there were such a thing. Consequently, the parent loop throws this error at the next check.

To get around this, I ended up insert this line after the child loop:

`if (it == vStringList.end()) --it;`

Dirty, but works :D

I know it may be obvious to some, but I've been scratching my head over this for a while, lol