mbe: treat <- as one punct

lowr · lowr · commit 767351fb8768 · 2022-12-27T18:34:46.000+09:00
diff --git a/crates/mbe/src/tt_iter.rs b/crates/mbe/src/tt_iter.rs
@@ -119,6 +119,7 @@ impl<'a> TtIter<'a> {
             }
             ('-' | '!' | '*' | '/' | '&' | '%' | '^' | '+' | '<' | '=' | '>' | '|', '=', _)
             | ('-' | '=' | '>', '>', _)
+            | ('<', '-', _)
             | (':', ':', _)
             | ('.', '.', _)
             | ('&', '&', _)
