Question

I’m using boost.python to make python-modules written in c++. I have some base class with pure virtual functions which I have exported like this:

class Base
{
    virtual int getPosition() = 0;
};

boost::python::class_<Base>("Base")
   .def("GetPosition", boost::python::pure_virtual(&Base::getPosition));

in Python I have code:

class Test(Base):
   def GetPosition(self):
      return 404

Test obj
obj.GetPosition()

RuntimeError: Pure virtual function called

What’s wrong?

Answer 1

This error happens when a constructor or a destructor directly or indirectly calls a pure virtual member.

(Remember that during constructor and destructor execution, the dynamic type is the constructed/destructed type and so virtual members are resolved for that type).