From 8aac1077ed495ef8d1241ce76d4b64d7eb13a856 Mon Sep 17 00:00:00 2001
From: Josh Stone <jistone@redhat.com>
Date: Tue, 7 Apr 2020 16:50:16 -0700
Subject: [PATCH] Reduce callsites in Chain::count()

---
 src/libcore/iter/adapters/chain.rs | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/src/libcore/iter/adapters/chain.rs b/src/libcore/iter/adapters/chain.rs
index 6c97c43df40..0100e62fae6 100644
--- a/src/libcore/iter/adapters/chain.rs
+++ b/src/libcore/iter/adapters/chain.rs
@@ -62,12 +62,15 @@ fn next(&mut self) -> Option<A::Item> {
     #[inline]
     #[rustc_inherit_overflow_checks]
     fn count(self) -> usize {
-        match self {
-            Chain { a: Some(a), b: Some(b) } => a.count() + b.count(),
-            Chain { a: Some(a), b: None } => a.count(),
-            Chain { a: None, b: Some(b) } => b.count(),
-            Chain { a: None, b: None } => 0,
-        }
+        let a_count = match self.a {
+            Some(a) => a.count(),
+            None => 0,
+        };
+        let b_count = match self.b {
+            Some(b) => b.count(),
+            None => 0,
+        };
+        a_count + b_count
     }
 
     fn try_fold<Acc, F, R>(&mut self, mut acc: Acc, mut f: F) -> R