name old ns/iter new ns/iter diff ns/iter diff % speedup
iter::bench_cycle_take_ref_sum 927,152 927,194 42 0.00% x 1.00
iter::bench_cycle_take_sum 938,129 603,492 -334,637 -35.67% x 1.55
(0i64..1000000).chain(1000000..).take_while(|&x| x < 1111111)
}
+bench_sums! {
+ bench_cycle_take_sum,
+ bench_cycle_take_ref_sum,
+ (0i64..10000).cycle().take(1000000)
+}
+
// Checks whether Skip<Zip<A,B>> is as fast as Zip<Skip<A>, Skip<B>>, from
// https://users.rust-lang.org/t/performance-difference-between-iterator-zip-and-skip-order/15743
#[bench]
_ => (usize::MAX, None)
}
}
+
+ #[inline]
+ fn try_fold<Acc, F, R>(&mut self, init: Acc, mut f: F) -> R where
+ Self: Sized, F: FnMut(Acc, Self::Item) -> R, R: Try<Ok=Acc>
+ {
+ let mut accum = init;
+ while let Some(x) = self.iter.next() {
+ accum = f(accum, x)?;
+ accum = self.iter.try_fold(accum, &mut f)?;
+ self.iter = self.orig.clone();
+ }
+ Try::from_ok(accum)
+ }
}
#[stable(feature = "fused", since = "1.26.0")]
let mut it = (0..).step_by(1).take(0).cycle();
assert_eq!(it.size_hint(), (0, Some(0)));
assert_eq!(it.next(), None);
+
+ assert_eq!(empty::<i32>().cycle().fold(0, |acc, x| acc + x), 0);
}
#[test]