How to provide cpp class destructor member information in cython

Asked Dec 30 '20 at 16:29

Active Dec 30 '20 at 16:29

Viewed 48 times

I have a scenario as follows,

c++ class

// Forward declared
class B;


class A {
   public:
   A();
   ~A(){val.reset();}

   std::unique_ptr<B> val;
}

cython

cdef cppclass A:
    A() except+

So, compiling this would gives error

/usr/include/c++/7/bits/unique_ptr.h:76:22: error: invalid application of ‘sizeof’ to incomplete type

and as per my knowledge this happens since there is no information about the class A destructor in cython definition and cython tends to use default destructor which and gets cornered because of unique_ptr with forward declared class.

Is there way to tackle this issue ?

asked Dec 30 '20 at 16:29

Ramakrishna Prabhu

And does it (if you create/destruct a variable of type A) get compiled as pure c++? I would be surprised. – ead Dec 30 '20 at 18:01
Related: https://stackoverflow.com/q/9954518/5769463 – ead Dec 30 '20 at 18:05
Just to clarify, the problem is with destroying the unique_ptr. Cython is irrelevant here (as ead suggests) – DavidW Dec 30 '20 at 18:41
@ead There will be definition for B somewhere in the library where the destructor has been defined, so C++ will compile. – Ramakrishna Prabhu Dec 30 '20 at 18:52
@DavidW as per one of those solutions, I have a destructor, so compiler doesn't have to generate a default destructor. – Ramakrishna Prabhu Dec 30 '20 at 18:55
No the c++ won't compile - try it. There may be a definition for `B` somewhere but the unique_ptr doesn't know that. – DavidW Dec 30 '20 at 19:08

How to provide cpp class destructor member information in cython

0 Answers0