[QUESTION] How to overload functions with argument of bool/int

[wyq730]

How can we overload the two functions like below?

void func(int);
void func(bool);

Even if we use overload_cast, Pybind11 will treat them as the same, so these two functions will not be distinguished in the generated Python interface.

Is there any solution to this problem?

Related discussion: #1625

[YannickJadoul]

Please refer to the explanation in the docs. pybind11 does overload resolution if you bind multiple functions to the same name in Python, but this is a distinct concept from overload_cast:

• https://pybind11.readthedocs.io/en/stable/classes.html#overloaded-methods
• https://pybind11.readthedocs.io/en/stable/advanced/functions.html#overload-resolution-order

[wyq730]

@YannickJadoul

Thanks for the reply.

Maybe the example was a little confusing, actually the two functions can have different names:

void func1(int);
void func2(bool);

And if we bind them to the same function name in Python:

m.def("func", &func1))
   .def("func", &func2));

The overload resolution will not work well. If we call func in Python with a bool argument:

func(False)

It will use the func1 under the hood. Because it doesn't require a conversion from bool to int in Python. But actually I want to use the func2.

Does this example make the question clear?

[YannickJadoul]

@wyq730 Right, so as I said, it's completely unrelated to overload_cast that you mention in the original issue (as explained in the docs).

The issue you yourself linked to does explain that since issubclass(bool, int), the order of overloads is crucial in this case: #1625 (comment)