Nullable properties support

[tapika]

I would like to support nullable properties, so when assigning None from python code, property would pass nullptr as a class instance instead.
Usage could be following for example:

b = ...
a.Link = b
...
a.Link = None

What I have tried:

struct A {}
struct B { A* link = nullptr; }

nb::class_<A>(m, "A");
nb::class_<B>(m, "B")
    .def_prop_rw("Link",
        [](B& b) { return b.link; },
        [](B& b, A* link) { b.link = link; },
        nb::arg("link").none());

Based on the documentation, it seems that this should be supported.

However, there's a compilation error that says:

nb_func.h(49,39): error C2338: The number of nb::arg annotations must match the argument count!

It seems that the root cause is that the same extra annotations are applied to both getter and setter, while they have different number of arguments.

Is this known limitation, can feature like this be supported in future ?

[yosh-matsuda]

I had the same problem but I use a custom rw property suggested in #236

[wjakob]

For posterity, this feature was added in commit 11a9b3c

[tapika]

Thanks for quick response. By quick test you changes seems to be work.