HH\Lib\Keyset\keys

This API is part of the Hack Standard Library, not HHVM itself.

Returns a new keyset containing the keys of the given KeyedTraversable, maintaining the iteration order

namespace HH\Lib\Keyset;

function keys<Tk as arraykey, Tv>(
    KeyedTraversable<Tk, Tv> $traversable,
): keyset<Tk>;

Parameters