From ff60eca7a127dc8a63bbbf66ba3c7d2d8afea681 Mon Sep 17 00:00:00 2001
From: Josh Stone <jistone@redhat.com>
Date: Thu, 11 Jul 2019 17:51:24 -0700
Subject: [PATCH] Avoid closures in Peekable

---
 src/libcore/iter/adapters/mod.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/libcore/iter/adapters/mod.rs b/src/libcore/iter/adapters/mod.rs
index 6123d09e21ca2..c19e51b2658d4 100644
--- a/src/libcore/iter/adapters/mod.rs
+++ b/src/libcore/iter/adapters/mod.rs
@@ -1235,7 +1235,10 @@ impl<I: Iterator> Iterator for Peekable<I> {
         };
         let (lo, hi) = self.iter.size_hint();
         let lo = lo.saturating_add(peek_len);
-        let hi = hi.and_then(|x| x.checked_add(peek_len));
+        let hi = match hi {
+            Some(x) => x.checked_add(peek_len),
+            None => None,
+        };
         (lo, hi)
     }