operator overloading with py::self and virtual base class

[harsszegi]

Hello,

is it possible to create operator== for a abstract base class?
with traditional "eq" it works fine fine, however with "py::self == py::self" I get an error:

pybind11/operators.h:163:1: error: invalid abstract return type 'IFoo'
PYBIND11_BINARY_OPERATOR(eq, eq, operator==, l == r)

I have in IFoo a ".def(py::self == py::self)"