Question

std::vector<Enemy*>::iterator it;
for(it;it!=tracked.end();it++){
    (*it)->update(timeSinceLastFrame);
}

tracked is the vector:

std::vector<Enemy*>

Why am I getting this error? (please say if I haven’t included enough details)

Answer 1

You never initialized the iterator.

for(std::vector<Enemy*>::iterator it = tracked.begin();it!=tracked.end();it++){
    (*it)->update(timeSinceLastFrame);
}

Many implementations (such as VC++, which you appear to be using) perform checks in debug to make sure that when two iterators are compared, they belong to the same object. A default constructed iterator does not belong to any particular instance, and as such the it != tracked.end() check will fail with that error.