Defining an rw property for a const char* field that can be null?

[nurpax]

Simplified example. Binding the IniFilename of ImGuiIO:

class ImGuiIO {
    const char* IniFilename;
}

Binding a str that cannot be None is easy, simply do:

nb::class_<ImGuiIO>(m, "IO")
   .def_rw("ini_filename", &ImGuiIO::IniFilename)

The IniFilename field can be either NULL or a pointer to a C string. I'd like to allow setting this field to either None or a string.

But how to go about accepting None that gets turned into a NULL?

The below is what I came up with but it feels a unwieldy. I wonder if I'm missing a simpler way?

.def_prop_rw("ini_filename", 
    [](ImGuiIO& io) {
        return io.IniFilename;
    },
    [](ImGuiIO& io, nb::handle filename) {
        const char* fname = !filename.is_none() ? nb::cast<const char *>(filename) : nullptr;
        io.IniFilename = fname;
    },
    "ini_filename"_a.none(),
    nb::for_getter(nb::sig("def ini_filename(self, /) -> str | None")),
    nb::for_setter(nb::sig("def ini_filename(self, filename: str | None, /) -> None"))