Plan for Exceptions and @nogc?

[via Digitalmars-d]

On Wednesday, 18 February 2015 at 20:47:36 UTC, deadalnix wrote:
> On Wednesday, 18 February 2015 at 20:25:07 UTC, Dicebot wrote:
>> Right now I don't care for full memory safety or type safety 
>> of any proposed solution. I will be glad to have any that 
>> actually works - and I have not heard of any idea that allows 
>> to do that without language changes. Your push for owned is 
>> also hardly relevant because exceptions are good examples of 
>> data with shared / non-determenistic ownership and thus won't 
>> benefit from it.
>
> I think it make sense to require that something thrown to be 
> owned. That means ownership can be transferred from one thread 
> to the other. That also mean that the compiler can free the 
> exception when it goes out of scope, which is what is wanted 
> for exception and @nogc to work together.
>
> The invalid operation in @nogc would become promoting owned to 
> Tl/shared/immutable rather than not allocating at all.
>
> This has added benefit to allow for way more code to be @nogc, 
> and in many cases transfers the GCness of something in the 
> caller, which makes for @nogc compatible libraries that can be 
> used in both @nogc and gc situation.
>
> If we are gonna add something in the language, it'd better be 
> worth it.

+1

Could you take the time to make a concrete proposal? I'll try to 
have another go at `scope`, which is of course deeply linked with 
ownership, and these two things need to work well together. I 
want to avoid proposing something that will later collide with 
your ideas.