Change to add 1 if non zero shift

diff --git a/crates/ra_mbe/src/lib.rs b/crates/ra_mbe/src/lib.rs
index b92312d5276aa0c838cadd2bd176e21e60f080b8..15f000175559d8581c3cfed09e7b16f91e71d641 100644 (file)
--- a/crates/ra_mbe/src/lib.rs
+++ b/crates/ra_mbe/src/lib.rs
@@ -108,7 +108,7 @@ pub fn parse(tt: &tt::Subtree) -> Result<MacroRules, ParseError> {
 
         // Note that TokenId is started from zero,
         // We have to add 1 to prevent duplication.
-        let shift = max_id(tt).unwrap_or(0) + 1;
+        let shift = max_id(tt).map_or(0, |it| it + 1);
         Ok(MacroRules { rules, shift })
     }