perlref.pod. Thanks for David Wheeler for starting the discussion
and Paul Johnson for confirming that it could actually be done.
p4raw-id: //depot/perl@25820
$coderef = *handler{CODE};
$ioref = *STDIN{IO};
$globref = *foo{GLOB};
+ $formatref = *foo{FORMAT};
All of these are self-explanatory except for C<*foo{IO}>. It returns
the IO handle, used for file handles (L<perlfunc/open>), sockets