I asked it again (in a new context) and got a partially right answer as well: > In C++, calling pop_back() on an empty vector results in an undefined behavior.

I asked it again (in a new context) and got a partially right answer as well: > In C++, calling pop_back() on an empty vector results in an undefined behavior. An std::vector is a dynamic array that grows and shrinks automatically. pop_back() function is used to remove the last element of the vector. But if there are no elements in the vector, calling pop_back() will result in an error. Therefore, it is advisable to always check if the vector is empty before calling pop_back(). I wonder what sort of scores we would be seeing for each of these series of tokens (including those returned for roel_v). Is the aggregate score (for lack of a better term) higher for the initial reply I saw greater than the scores for these other replies?