Requires the Hack Standard Library to be installed.
Facebook Engineer?

This function is available as Dict\gen_filter() in Facebook's www repository.

Returns a new dict containing only the values for which the given async predicate returns true

namespace HH\Lib\Dict;

function filter_async<Tk as arraykey, Tv>(
  KeyedContainer<Tk, Tv> $traversable,
  (function(Tv): Awaitable<bool>) $value_predicate,
): Awaitable<dict<Tk, Tv>>;

For non-async predicates, see Dict\filter().

Time complexity: O(n * p), where p is the complexity of $value_predicate Space complexity: O(n)