shared members and castings

[Steven Schveighoffer]

On Sat, 12 Nov 2011 15:20:54 -0500, nrgyzer <nrgyzer at gmail.com> wrote:

> Hi guys,
>
> is there any way to use shared members without casting them? Fox example:
>
> class Example {
>
>     private shared HashSet!(string) ex;
>
>     ...
>
>     this() {
>         ex = cast(shared) new HashSet!(string)();
>     }
>
>     void write() {
>         foreach (ref c; cast(HashSet!(string)) ex) {
>             std.stdio.writeln(c);
>         }
>     }
> }
>
> Without casting, I always get some errors. My classes contains many  
> different
> collections and values, so I've many casts which makes the code at some  
> points
> a bit unclear. Is there any way to prevent the casting from/to shared  
> objects?

The objects have to implement shared methods directly.  From your sample  
code, I assume you are using dcollections.

I have not yet thought about how to tackle shared versions of containers.   
Certainly, your code is not a good way to do it, since you are not doing  
any synchronization.

The issue is, if a container is shared, you may only call shared methods  
on it.  I have no shared methods in dcollections, because they would be  
simple wrappers for synchronizing the methods on the container.  I would  
like to find an automatic way to do this rather than use boilerplate  
everywhere.

I also would like to investigate shared-aware containers that are safer to  
use (possibly lock-free) than simply synchronizing all methods.

-Steve