Passing shared delegates

[Martin Drasar]

Okay, I have hit another thing when dealing with shared delegates.

Consider this code:

> alias void delegate (B b) shared Callback;
> 
> class A
> {
>   private B _b;
> 
>   this (B b)
>   {
>     _b = b;
>   }
> 
>   void callback (B b) shared
>   {
>     b.execute(&callback);
>     //_b.execute(&callback); <-- Uncomment this for error
>   }
> }
> 
> class B
> {
>   void execute (Callback c)
>   {
>     c(this);
>   }
> }
> 
> void main()
> {
>   auto b = new B();
>   auto a = new A(b);
> 
>   b.execute(&a.callback);
> }

If I uncomment that line I get this error:

> Error: function main.B.execute (void delegate(B b) shared c) is not callable using argument types (void delegate(B b) shared) shared

This error probably appears because typeof b is B and typeof _b is
shared(B). My question is - why? Is it a bug or does the shared delegate
made it shared and it is ok? And what to do with it? I can cast away
shared of _b, but is it a correct and clean way?

Thanks for your input.

Martin