any news on const/invariant?

[Walter Bright]

Bill Baxter wrote:
> Here's a class that compiles fine and will probably mostly work.
> 
> class Klass {
> 
>     this() {
>         array.length = 10;
>     }
>     const int elem(int i) {
>         return array[i];
>     }
> 
>     int[] array;
> 
> }
> 
> But someday when someone tries to call elem() with a const Klass it will 
> fail to compile.

Yes. So where's the problem? Also, why would one want to return a "const 
  int"? It doesn't make much sense.



> Also in case anyone else wasn't sure, this is how you declare the common 
> idiom of const method returning a const reference in the latest D2.008:
> 
>    const const(int*) get_elem_ptr(int i) {...}
> 
> Without the parens it gives "Redundant storage class".  (However 
> declaring it "public public public" still does not create an error...)
> 
> Also const int* get_elem_ptr(int i) fails to compile because it tries to 
> return a mutable pointer from a const method.  So that case is ok, but 
> the one in Klass above seems like trouble brewing to me.
> 
> --bb