[op25-dev] Building under Ubuntu 12.04 - blocks gives error "op25.cc:3115:13: error: 'ptrdiff_t' does not name a type"

OK I've just upgraded my Ubuntu box to 12.04, from 11.04 (couldn't help myself). I'm trying to rebuild op25 but I'm getting the following error, followed by a string of relate ones (I'm guessing) Compiling blocks: op25.cc:3115:13: error: 'ptrdiff_t' does not name a type A Google search for this kind of error seems to be pointing to stricter typedef requirements by gcc 4.6 with the solution being to include an additional system header file cstddef. However I'm not sure where to include this in the op25 source. I tried putting it in the op25.i swig interface file so that it ends up in the generated op25.cc file however that doesn't appear to have worked. Anyone already solved this or can provide some guidance? Ubuntu 12.04 appears to be using gcc 4.6.3 Thanks Cheers Richard