Resolve clippy redundant_pattern_matching lint
diff --git a/gen/write.rs b/gen/write.rs
index 9ae114d..59e12ed 100644
--- a/gen/write.rs
+++ b/gen/write.rs
@@ -672,7 +672,7 @@
             write!(out, "::rust::Str::Repr error$ = ");
         }
         write!(out, "{}(", invoke);
-        if let Some(_) = &sig.receiver {
+        if sig.receiver.is_some() {
             write!(out, "*this");
         }
         for (i, arg) in sig.args.iter().enumerate() {