Method execute

src/ExtOperator.h:62–67

          std::string,
          std::function<Future<Void>(Reference<IReadWriteContext>, StringRef const&, bson::BSONElement const&)>> {
	static Future<Void> execute(std::string const& op,
	                            Reference<IReadWriteContext> cx,
	                            StringRef const& path,
	                            bson::BSONElement const& element) {
		return dispatch(op)(cx, path, element);
	}
};

#define REGISTER_UPDATE_OPERATOR(Op, Key)                                                                              \