Casting from nb::ndarray<T> to nb::ndarray<>?

[mreineck]

I'm experimenting with porting a fairly large numerical library (https://gitlab.mpcdf.mpg.de/mtr/ducc) from pybind11 to nanobind. Things aren't looking too bad, but one recurring theme is that I cannot implicitly cast an array of a well-defined type (i.e. nb::ndarray<T>) to a generic nb::ndarray<>. In pybind11 there was an implicit conversion from py::array_t<T> to py::array. Is there a way for me to emulate this?

[wjakob]

Does this not work? It is part of the ndarray class definition.

    template <typename... Args2>
    explicit ndarray(const ndarray<Args2...> &other) : ndarray(other.m_handle) { }

The idea here is that you hopefully know what you are doing. Nanobind performs no checks.

[mreineck]

Thanks for pointing out that the constructor is explicit, that was the bit I was missing!
I'll check this as soon as possible.

Concerning the missing checks ... I still try to get a feeling for nanobind and its relation to pybind11, so it is very possible that I'm doing stupid things. But I'm not in a hurry with the migration and I'm rather confident to get everything sorted out in time ;-)