nested inout return type

[Simon Bürger via Digitalmars-d-learn]

I'm writing a custom (originally multi-dimensional) Slice-type, 
analogous to the builtin T[], and stumbled upon the problem that 
the following code won't compile. The workaround is simple: just 
write the function three times for mutable/const/immutable. But 
as "inout" was invented to make that unneccessary I was wondering 
if there is a clever way to make this work.

struct Slice(T)
{
    T* ptr;
    size_t length;

    Slice!(inout(T)) opSlice(size_t a, size_t b) inout
    {
        return Slice!(inout(T))(ptr+a, b-a);
    }
}