Avoid GC with closures

[ZombineDev via Digitalmars-d]

On Sunday, 29 May 2016 at 11:16:57 UTC, Dicebot wrote:
> On 05/28/2016 09:58 PM, Iakh wrote:
>> Yeah. It doesn't capture any context. But once it does it 
>> would be an error.
>
> Custom allocators are not very suitable for things like 
> closures because of undefined lifetime. Even if it was allowed 
> to replace allocator, you would be limited to either GC or RC 
> based one anyway to keep things @safe.

Maybe an interface for a ref counting allocator (that leverages 
Andrei's idea to use AffixAllocator's interface for storing RC 
metadata) can be used, provided that the interface is in druntime 
and the compiler knows how to use it.

BTW, AffixAllocator's interface abstracts whether the metadata is 
stored next to the allocation or in a separate area, but the 
current design needs to be fixed w.r.t to shared-ness, because it 
breaks the type system: 
http://forum.dlang.org/post/bscksxwxuvzefymbiemg@forum.dlang.org