Function qr_backend 

pub fn qr_backend<T>(
    a: TypedTensor<T>,
) -> Result<(TypedTensor<T>, TypedTensor<T>), BackendLinalgError>
where
    T: BackendLinalgScalar,

Compute a thin/economy QR decomposition, consuming the input tensor so its column-major storage can be transferred to the backend without copying.

Errors

Returns an error when the QR fails (a backend or non-convergence /// failure).