[dmd-concurrency] tail-shared by default?

[Walter Bright]

Steve Schveighoffer wrote:
> ----- Original Message ----
>
>   
>> From: Walter Bright <walter at digitalmars.com>
>>
>> Steve Schveighoffer wrote:
>>     
>>> The only caveat is, we would *need* to change the semantics of shared so that 
>>>       
>> you can have a non-shared reference to a shared class instance easily.
>>
>> That's the so-called "tail-shared" problem. We tried (hard) to make "tail-const" 
>> work, where the reference is mutable but the contents were const. It sounds 
>> simple, but just does not work in a language with implicit reference semantics.
>>     
>
> Yes, but this isn't const, it is shared.

To the type construction system, they are handled the same. Tail-shared 
will have the same insurmountable problems that tail-const had.

>
> What do you think about this?
>
>
>   

I tried desperately to make tail-const work. It wasn't going to, and 
neither is tail-shared for the same reasons.