HH\Lib\Keyset\keys

This API is part of the Hack Standard Library, not HHVM itself.
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This function is available as Keyset\keys() in Facebook's www repository.

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

Description

namespace HH\Lib\Keyset;

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

Parameters