From f0483f76e6feb256abffb060029f57e09c6d4dc0 Mon Sep 17 00:00:00 2001
From: Shotaro Yamada <sinkuu@sinkuu.xyz>
Date: Mon, 17 Dec 2018 09:35:28 +0900
Subject: [PATCH] Remove `<Cycle as Iterator>::try_fold` override
It was a incorrect optimization.
---
src/libcore/iter/mod.rs | 13 -------------
src/libcore/tests/iter.rs | 2 ++
2 files changed, 2 insertions(+), 13 deletions(-)
diff --git a/src/libcore/iter/mod.rs b/src/libcore/iter/mod.rs
index 7b273f7862a1f..aa23d49672a0b 100644
--- a/src/libcore/iter/mod.rs
+++ b/src/libcore/iter/mod.rs
@@ -649,19 +649,6 @@ impl<I> Iterator for Cycle<I> where I: Clone + Iterator {
_ => (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")]
diff --git a/src/libcore/tests/iter.rs b/src/libcore/tests/iter.rs
index 4efa01363146b..00b4aa4fa2d7a 100644
--- a/src/libcore/tests/iter.rs
+++ b/src/libcore/tests/iter.rs
@@ -1003,6 +1003,8 @@ fn test_cycle() {
assert_eq!(it.next(), None);
assert_eq!(empty::<i32>().cycle().fold(0, |acc, x| acc + x), 0);
+
+ assert_eq!(once(1).cycle().skip(1).take(4).fold(0, |acc, x| acc + x), 4);
}
#[test]