이 레슨은 당분간 영어로 제공돼요.
Generics with rules
Inside first<T>, TypeScript knows nothing about T, so you cannot read .id or .length on it. A constraint states what every T must at least have.
이 레슨은 당분간 영어로 제공돼요.
Inside first<T>, TypeScript knows nothing about T, so you cannot read .id or .length on it. A constraint states what every T must at least have.