[Pyrex] Problems with compiling a module using a C++ compiler

[Matthias Baas]

Hi,

I have a problem with Pyrex 0.8.2 on Windows (XP) and VC6. When I try to 
compile Pyrex generated C code actually using the C++ compiler (i.e. my 
Pyrex output file has suffix .cpp) then the compiler generates errors.

Here's an example Pyrex file:

##########################################
# File: xtest.pyx

# An arbitrary extension type...
cdef class MyClass:
     def __init__(self):
         pass

# A function that expects a MyClass object as input and
# assigns it to a local variable of the same type
def foo(MyClass mc):
     cdef MyClass local_mc

     local_mc = mc

##########################################

I'm using the following setup script to compile the module. Note that I 
call the output file xtest.cpp instead of just xtest.c so when compiling 
the module the C++ compiler will be invoked.

##########################################
# File: setup.py

from distutils.core import setup, Extension
import os

# Run Pyrex and generate a *.cpp (!) file
os.system("pyrexc -o xtest.cpp xtest.pyx")

setup(name="xtest",
       ext_modules=[Extension("xtest", ["xtest.cpp"])])
##########################################

When I try to compile the module I get two errors saying that the left hand 
operand must be an L value.

The offending lines are these:

   ((PyObject*)__pyx_v_local_mc) = Py_None;
   ...
   ((PyObject *)__pyx_v_local_mc) = ((PyObject *)__pyx_v_mc);


The problem is the cast on the left hand side. I've never seen that before 
and don't know if this is valid C/C++ code. But anyway, VC6 chokes on it 
(however, it does not complain when compiled as pure C code). Can this be 
changed in Pyrex so that casts only appear on the right hand side? (in this 
particular case the second line wouldn't even require a cast as both 
variables are of the same type)

I'm using the .cpp suffix because I'm trying to wrap a C++ library which 
has to be compiled using a C++ compiler (and needs the C++ runtime library).

- Matthias -