How to check whether STL iterator points at anything? [duplicate]

Answer 1

You can't. The usual idiom is to use the container's end iterator as a 'not found' marker. This is what std::find returns.

std::vector::iterator i = std::find(v.begin(), v.end(), 13);
if (i != v.end())
{
     // ...
}

The only thing you can do with an unassigned iterator is assign a value to it.