Document shape argument concept / requirements

[burnpanck]

I am currently struggling to apply xt::reshape_view onto a xt::xtensor<T,N> into shape given by a xt::xtensor<std::uint16_t,1>. What exactly passes for the shape argument of that function? I have tried xt:cast<std::size_t> to no avail, so I'm a bit struggling with if the problem is with the element type or the container, or possibly others.
Previously, I had a similar issue with xt::zeros. In the case of xt::empty, it's clearly documented and obvious that only specific types pass, but that one is of course somewhat special.

[JohanMabille]

Hi,

Looks like you found a bug, we are missing specializations of some internal structures for reshaping. Because of that, shape arguments cannot have the type xtensor or xarray. You can workaround that by using the storage of the xtensor object:

        xt::xtensor<int, 2> a = {{1, 3}, {2 ,4}};
        xt::xtensor<uint16_t, 1> sh = {2};
        auto z = xt::reshape_view(a, sh.storage());