*/ function implementsInterface($value): string { Assert::implementsInterface($value, Serializable::class); return $value; } /** * @psalm-pure * * @param mixed $value * * @return null|class-string */ function nullOrImplementsInterface($value): ?string { Assert::nullOrImplementsInterface($value, Serializable::class); return $value; } /** * @psalm-pure * * @param mixed $value * * @return iterable> */ function allImplementsInterface($value): iterable { Assert::allImplementsInterface($value, Serializable::class); return $value; } /** * @psalm-pure * * @param mixed $value * * @return iterable|null> */ function allNullOrImplementsInterface($value): iterable { Assert::allNullOrImplementsInterface($value, Serializable::class); return $value; }