GC/non-GC memory as part of data type?

[Gregor Mückl]

On Wednesday, 13 November 2019 at 15:25:46 UTC, James Lu wrote:
> On Wednesday, 13 November 2019 at 15:19:38 UTC, Gregor Mückl 
> wrote:
>> Hi!
>>
>> This is an attempt to follow up on the DIP1025 discussion: 
>> what happens if all pointers/arrays/references carry the 
>> origin of the pointed to memory region as part of their type? 
>> The goal is to have a cleaner, more explicit separation of GC 
>> and non-GC heaps.
>>
>> [...]
>
> We could add @nogc types. That indicates to the implementation
> that the memory held by that type MAY be ignored by the GC and 
> that
> that any pointers held in that type MUST NOT be moved by a 
> moving
> GC.
>
> Alternatively, "special" pointers could have a .toPointer 
> function
> that converts itself into the memory address they mean. 
> Applications
> include XOR pointers.

Haven't thought about moving GC allocated memory yet. Does the 
current D spec even allow this? The way you're allowed to take 
pointers to GC memory and store them in places unknown to the GC 
should prevent it.