HH\Lib\Keyset\flatten
Requires the Hack Standard Library to be installed.
Facebook Engineer?
This function is available as Keyset\flatten() in Facebook's www repository.
Returns a new keyset formed by joining the values within the given Traversables into a keyset
namespace HH\Lib\Keyset;
function flatten<Tv as arraykey>(
Traversable<Container<Tv>> $traversables,
): keyset<Tv>;
For a fixed number of Traversables, see Keyset\union().
Time complexity: O(n), where n is the combined size of all the
$traversables
Space complexity: O(n), where n is the combined size of all the
$traversables
Parameters
Returns
keyset<Tv>