[C++-sig] python override of C++ virtual mem fun not exactly working yet

[DRandallTaylor]

DRandallTaylor <DRandallTaylor <at> yahoo.com> writes:

> [...]

May I rephrase?

Is conversion from a Python class to the boost::python type that it is derived 
from automatic?  I think it probably is, therefore I must be doing something 
wrong:


class InboxListener(VIAmCallback):
	def __init__(self, sess):
		VIAmCallback.__init__(self)
		self.inbox = sess.CreateInbox(self)


gives me:


  File "test.py", line 32, in run
    listener = InboxListener(sess)
  File "test.py", line 10, in __init__
    self.inbox = sess.CreateInbox(self)
ArgumentError: Python argument types in
    VIAmSession.CreateInbox(VIAmSession, InboxListener)
did not match C++ signature:
    CreateInbox(class tt_stream_ns::VIAmSession {lvalue}, class 
tt_stream_ns::VIAmCallback {lvalue})



And my C++ looked like this:


struct VIAmCallbackPublic : public tt_stream_ns::VIAmCallback
{
   [...]
};
struct VIAmCallbackWrap : public VIAmCallbackPublic, 
python::wrapper<VIAmCallbackPublic>
{
   [...]
]

python::class_ <VIAmCallbackWrap, boost::noncopyable>("VIAmCallback")
        .def("OnData", &VIAmCallbackPublic::OnData,
              &VIAmCallbackWrap::default_OnData);



And I thought that the Python error message above tells me that python does 
NOT believe that InboxListener is actually a tt_stream_ns::VIAmCallback.  So I 
experimented by added a python::bases<> template template arg like this:


python::class_ <
  VIAmCallbackWrap
  , python::bases<VIAmCallbackPublic, tt_stream_ns::VIAmCallback>
  , boost::noncopyable
> ("VIAmCallback")
def("OnData", &VIAmCallbackPublic::OnData,
    &VIAmCallbackWrap::default_OnData);


And then I get a worse error from Python:


Traceback (most recent call last):
  File "test.py", line 1, in ?
    from pycore import *
RuntimeError: extension class wrapper for base class struct VIAmCallbackPublic 
has not been created yet



Am I completely clueless or simply overlooking something.  Please tell me it 
is the latter.


Sincerely,
Your Faithful n00b.

DRandallTaylor