Pipeline tee?

[Ethan Romander]

Is there any facility for creating a tee in the Crypto++ pipeline 
metaphor?  I would like a filter object that sends the same input to two 
different BufferedTranformation objects.  Specifically, I would like to 
create a single pipeline that would compute a message MAC using a 
HashFilter and encrypt the message using a StreamTranformationFilter.  I'd 
like to feed these filters from a single FileSource.

Is there a simple way to do this that I have overlooked in the 
"documentation"?  Thanks for your suggestions.

--Ethan