From 2ea0410f090ae06d18f5535e62e888e49a4f21a7 Mon Sep 17 00:00:00 2001
From: Soveu <marx.tomasz@gmail.com>
Date: Fri, 30 Apr 2021 16:13:00 +0200
Subject: [PATCH] str::is_char_boundary - slight optimization

---
 library/core/src/str/mod.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/library/core/src/str/mod.rs b/library/core/src/str/mod.rs
index 95dd54976b2c..e7970bf5c8f1 100644
--- a/library/core/src/str/mod.rs
+++ b/library/core/src/str/mod.rs
@@ -195,11 +195,11 @@ impl str {
         // 0 and len are always ok.
         // Test for 0 explicitly so that it can optimize out the check
         // easily and skip reading string data for that case.
-        if index == 0 || index == self.len() {
+        if index == 0 {
             return true;
         }
         match self.as_bytes().get(index) {
-            None => false,
+            None => index == self.len(),
             // This is bit magic equivalent to: b < 128 || b >= 192
             Some(&b) => (b as i8) >= -0x40,
         }