Interesting PRs: bringing type system legitimacy to shared allocators

[Andrei Alexandrescu via Digitalmars-d]

On 05/01/2017 08:12 AM, Guillaume Piolat wrote:
> On Sunday, 30 April 2017 at 21:43:26 UTC, Andrei Alexandrescu wrote:
>>
>> A pass through the root allocators (Mallocator, GCAllocator etc)
>> figuring out what attributes could be meaningfully attached would be
>> welcome. The rest would rely on inference.
>>
>>
>> Thanks,
>>
>> Andrei
>
> IAllocator being fully @nogc would be a comforting guarantee, as runtime
> dispatch makes for lighter types.

As I said (and am encouraging you to do this), this is achieved through 
simple variance:

interface INoGCAllocator : IAllocator {
    ... override all methods here as @nogc ...
}

This is possible because a @nogc method may override one that is not 
@nogc. @nogc being more restrictive it is contravariant with no- at nogc.

Also IAllocator should have a few @nogc methods to start with; there's 
no reason e.g. for empty() to create garbage.

Could you please initiate a PR?


Andrei