#[inline]
pub fn times(n: usize) -> Times
{
Times{i: 0, n: n}
}
#[derive(Copy, Clone)]
pub struct Times {
i: usize,
n: usize,
}
impl Iterator for Times
{
type Item = usize;
#[inline]
fn next(&mut self) -> Option<usize>
{
let elt = self.i;
if self.i < self.n {
self.i += 1;
Some(elt)
} else { None }
}
#[inline]
fn size_hint(&self) -> (usize, Option<usize>)
{
let len = self.n - self.i;
(len, Some(len))
}
}
impl DoubleEndedIterator for Times
{
#[inline]
fn next_back(&mut self) -> Option<usize>
{
if self.i < self.n {
self.n -= 1;
Some(self.n)
} else { None }
}
}
impl ExactSizeIterator for Times { }