I recently was wanting to use SYB for an AST datatype which includes constants like CDouble/CFloat.  Currently Data.Data exports Int8...Int64 and Word instances, but no instances for Foreign.C.Types:

Is there any reason these instances should not be exported by Data.Data?  The proposal here is simply to add them.  It's  just a matter of copy-pasting the existing instances and I can provide the patch.

  -Ryan