The function find_first_of searches for the first occurrence of a value.
template<class ForwardIterator1, class ForwardIterator2> ForwardIterator1 find_first_of (ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2, ForwardIterator2 last2); template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate> ForwardIterator1 find_first_of (ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
Returns the iterator to the first value or the last1 argument if none is found.