Interesting PRs: bringing type system legitimacy to shared allocators

[Andrei Alexandrescu via Digitalmars-d]

On 04/27/2017 07:35 PM, Stanislav Blinov wrote:
> IAllocator is too high level an interface, it doesn't carry any
> information as to what type of memory it can allocate (so we can only
> assume unshared), and does or does it not use GC (so we can only assume
> GC).

Initially all fresh memory is unshared. Whether or not the user 
subsequently shares it is of no consequence to the allocator. Allocators 
must, however, distinguish between reentrant and non-reentrant calls to 
the allocation primitives.

With regard to whether the memory is collectable or not we need some 
more thinking.

> If we are to devise types with allocators as members instead of type
> arguments, we need the additional information. Better to catch invalid
> assignment at compile time than to chase down how a stack allocator from
> one thread ended up in another.

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