Merge pull request #331 from fox0/clippy--manual_range_contains

split: Fix clippy::manual_range_contains

Author: jgarzik

file/split.rs

@@ -68,7 +68,7 @@ impl Suffix {
     }
 
     fn inc_char(ch: char) -> char {
-        debug_assert!('a' <= ch && ch < 'z');
+        debug_assert!(('a'..='y').contains(&ch));
         ((ch as u8) + 1) as char
     }
 }