simplify determining whether the field is a tuple field

Author: optimalstrategy

crates/ra_ide/src/diagnostics.rs

@@ -187,11 +187,7 @@ fn check_struct_shorthand_initialization(
         if let (Some(name_ref), Some(expr)) = (record_field.name_ref(), record_field.expr()) {
             let field_name = name_ref.syntax().text().to_string();
             let field_expr = expr.syntax().text().to_string();
-            let field_name_is_tup_index = name_ref
-                .syntax()
-                .first_token()
-                .map(|token| token.kind().is_literal())
-                .unwrap_or(false);
+            let field_name_is_tup_index = name_ref.as_tuple_field().is_some();
             if field_name == field_expr && !field_name_is_tup_index {
                 let mut edit_builder = TextEditBuilder::default();
                 edit_builder.delete(record_field.syntax().text_range());