HH\Set::filterWithKey

Returns a Set containing the values of the current Set that meet a supplied condition applied to its "keys" and values

public function filterWithKey(
  (function(arraykey, Tv): bool) $callback,
): Set<Tv>;

Since Sets don't have keys, the callback uses the values as the keys as well.

Only values that meet a certain criteria are affected by a call to filterWithKey(), while all values are affected by a call to mapWithKey().

Parameters

• (function(arraykey, Tv): bool) $callback

Returns

• Set<Tv> - a Set containing the values after a user-specified condition is applied to the values of the current Set.