template<class InputIterator, class ForwardIterator>
InputIterator
find_first_of(InputIterator first1, InputIterator last1,
ForwardIterator first2, ForwardIterator last2);
template<class ExecutionPolicy, class InputIterator, class ForwardIterator>
InputIterator
find_first_of(ExecutionPolicy&& exec,
InputIterator first1, InputIterator last1,
ForwardIterator first2, ForwardIterator last2);
template<class InputIterator, class ForwardIterator,
class BinaryPredicate>
InputIterator
find_first_of(InputIterator first1, InputIterator last1,
ForwardIterator first2, ForwardIterator last2,
BinaryPredicate pred);
template<class ExecutionPolicy, class InputIterator, class ForwardIterator,
class BinaryPredicate>
InputIterator
find_first_of(ExecutionPolicy&& exec,
InputIterator first1, InputIterator last1,
ForwardIterator first2, ForwardIterator last2,
BinaryPredicate pred);
Effects: Finds an element that matches one of a set of values.
Returns: The first iterator i in the range [first1, last1) such that for some iterator j in the range [first2, last2) the following conditions hold: *i == *j, pred(*i,*j) != false. Returns last1 if [first2, last2) is empty or if no such iterator is found.
Complexity: At most (last1-first1) * (last2-first2) applications of the corresponding predicate.