Stream wrapper support in realpath()

AFAICS realpath() currently only works with files and not other stream
wrappers.

Is there any chance that realpath() will support custom stream wrappers?
I think it can be implemented in a BC way: If the wrapper class doesn't
have a wrapper::realpath() method, realpath() just returns false like it
does today.

I hope this is the right place to ask.

Thanks,
Christian