Is there any documentation for implementing non-extern cppclass?

[Tapan Hazarika]

I've been experimenting with a non-extern cppclass and found behavior that I couldn't find documented anywhere.

For example:

cdef cppclass Xyz:
    int x

    Xyz() nogil:
        this.x = 42
    void __dealloc__():
        pass

generates (simplified):

struct Xyz {
     int x; void __pyx_f___init__Xyz();
    void __pyx_f___dealloc__Xyz();
   Xyz() { __pyx_f___init__Xyz(); }
   ~Xyz() { __pyx_f___dealloc__Xyz(); }
};
void Xyz::__pyx_f___init__Xyz() { this->x = 42; }

I couldn't able to find any documentation describing what is supported. 

[da-woods]

I think you're right and it isn't documented anywhere.

To me it's always seemed like a feature that probably shouldn't have been part of Cython. Mostly because it will always be fairly limited compared to just writing the C++ classes, so I don't think it's possible to get something that everyone's happy with without re-implementing C++ completely.  So I think the history was that it was added as an experimental feature and never documented. I don't think there's any chance of it being removed now, but personally I don't think the documentation should enthusiastically promote the feature.

If you look in tests/run/cpp_classes_def.pyx in the Cython repo, you can see a bunch of examples - that's probably the best I can recommend.

David

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[Tapan Hazarika]

Thanks!

That clears it up. It's also great to hear that it won't be removed. I'll definitely take a look at tests/run/cpp_classes_def.pyx.

Thanks again!