pub struct RepeatN<A>
{
elt: Option<A>,
n: usize,
}
impl<A> RepeatN<A>
{
pub fn new(elt: A, n: usize) -> Self
{
if n == 0 {
RepeatN{elt: None, n: n}
} else {
RepeatN{elt: Some(elt), n: n}
}
}
}
impl<A> Iterator for RepeatN<A> where
A: Clone,
{
type Item = A;
fn next(&mut self) -> Option<Self::Item>
{
if self.n > 1 {
self.n -= 1;
self.elt.as_ref().cloned()
} else {
self.n = 0;
self.elt.take()
}
}
fn size_hint(&self) -> (usize, Option<usize>)
{
(self.n, Some(self.n))
}
}
impl<A> DoubleEndedIterator for RepeatN<A> where
A: Clone,
{
#[inline]
fn next_back(&mut self) -> Option<Self::Item>
{
self.next()
}
}
impl<A> ExactSizeIterator for RepeatN<A> where
A: Clone,
{
}