The shortcut for meta-functions allows invoking them directly from an instance
of meta_type or meta_any. If the meta-function was not found or the arguments
don't match its signature an invalid meta_any object is returned.
The shortcut for meta-data allows getting and setting meta-data directly from an
instance of meta_type of meta_any. If the meta_data was not found or
getting/setting it failed and invalid meta_any object is returned.
Signed-off-by: Innokentiy Alaytsev <alaitsev@gmail.com>