enum ReservationState: string {
    case Pending = 'pending';
    case Confirmed = 'confirmed';
    case Cancelled = 'cancelled';
}

/**
 * @param value-of<ReservationState> $value
 */
function makeState(string $value): ReservationState {
    return ReservationState::from($value);
}

makeState(ReservationState::Pending->value); // Works
makeState('confirmed'); // Works
makeState('foo'); // Doesn't work