I just started using Matlab, and I absolutely despise (or not properly understand), the typesystem (or lack thereof).

Why does this not work ? I just want structs within structs (in a recursive function)

```
    K>> d = struct('op',1,'kids',[])

    d = 

          op: 1
        kids: []

    K>> d.kids(1) = struct('op',2)
    Conversion to double from struct is not possible.

```

I tried other things, like making `d=struct('op',1,'kids', struct([]))`, but nothing seems to work....