pub trait IterUtilsExt: Iterator {
/// Return the first element that maps to `Some(_)`, or None if the iterator
/// was exhausted.
fn ex_find_map<F, R>(&mut self, mut f: F) -> Option<R>
where
F: FnMut(Self::Item) -> Option<R>,
{
for elt in self {
if let result @ Some(_) = f(elt) {
return result;
}
}
None
}
/// Return the last element from the back that maps to `Some(_)`, or
/// None if the iterator was exhausted.
fn ex_rfind_map<F, R>(&mut self, mut f: F) -> Option<R>
where
F: FnMut(Self::Item) -> Option<R>,
Self: DoubleEndedIterator,
{
while let Some(elt) = self.next_back() {
if let result @ Some(_) = f(elt) {
return result;
}
}
None
}
}
impl<I> IterUtilsExt for I where I: Iterator {}