[julia-users] How to create array wrapper with constrains on type and number of dimensions

[Andrei Zh]

I'm trying to do something like this (which doesn't compile in its current 
form): 

type ArrayWrapper{T,N,AT <: AbstractArray{T,N}} <: AbstractArray{T,N}
   arr::AT{T,N}
end

That is:

   - wrapper around any type AT inherited from AbstractArray{T,N}
   - wrapper should be itself parametrized by T and N
   - wrapper should itself extend AbstractArray{T,N}

The code above currently gives an error:

ERROR: TypeError: instantiate_type: expected TypeConstructor, got TypeVar


 and the closest thing that works looks like this: 

type ArrayWrapper{T,N,AT <: AbstractArray} <: AbstractArray{T,N}
    arr::AT
end

which looks too unconstrained. 

Is there a way to get what I need?