{"ast_node_type":"variable","tokens":[{"end":77,"kind":"keyword","start":0,"text":"let"}]}
            let field_dest = self.project_field(&variant_dest, field_index)?;
            let field_index = active_field_index.unwrap_or(field_index);
            let op = self.eval_operand(operand, Some(field_dest.layout))?;