On 27 May 2012 at 20:37, Suresh Joshi wrote: > (2) From Python, I would like to manipulate the memory of a buffer stored > within Foo. In my REAL code, the only accessor I can use is Address() which > returns a void pointer, which Py++/BP flips into an opaque pointer (which I > don't think I can use to manipulate m_buffer's memory in Python). > > One option is ctypes, but I frankly just don't know how to combine that with > BP for the purpose of manipulating data behind a void*, even after having > looked at the ctypes integration code in the Py++ docs. > > The other option is to do something like what I did with the fake VoidPtr() > accessor. I could create accessors like VoidPtrAsUChar() for example, and > then expose those using the return_addressof call policy (hopefully!). If > this is, in fact, a valid approach, then I have the same question as > above... > > Given that I can't change the Foo.hpp code, is there a clean way of > injecting those AsUChar, AsInt, As... helper methods straight into the > wrapper code, so that they call Address() internally and then > reinterpret_cast the returned void* into something more useful and > accessible in Python?
If you really, really want to do this, I would have the wrapper of your Address method return an array-like interface e.g. like a std::vector<>. Look into the indexing suite - a method of implementing direct image bitmap access from python came up on this list a few years back. Niall -- Technology & Consulting Services - ned Productions Limited. http://www.nedproductions.biz/. VAT reg: IE 9708311Q. Work Portfolio: http://careers.stackoverflow.com/nialldouglas/ _______________________________________________ Cplusplus-sig mailing list Cplusplus-sig@python.org http://mail.python.org/mailman/listinfo/cplusplus-sig
