c++ stl what does base() do

Question

I have such code :

vector  v;
for (int i=0; i<5; i++)
        v.push_back(i);
v.erase(find(v.rbegin(), v.rend(),2).base());

This

Answer 1

base() returns the underlying base iterator.

The base iterator refers to the element that is next to the element the reverse_iterator is currently pointing to. That is std::reverse_iterator(it).base() == std::next(it).

You can learn more about reverse_iterator here.