Head Const

[Dicebot via Digitalmars-d]

On 02/17/2016 08:48 PM, Marc Schütz wrote:
> On Wednesday, 17 February 2016 at 02:20:15 UTC, Dicebot wrote:
>> One example of a existing guarantee you won't be able to keep, for
>> example, is that any immutable allocation can be completely put into
>> separate read-only memory.
> 
> Yes, and it would be rejected statically (rule 2). I therefor don't
> consider this a problem.

You pretty much prohibit any but typed allocators this way. I do see it
as a problem.

>> A very important property for building optimized allocators if you
>> keep in mind sharing goals of immutability.
> 
> This is considered too (rule 3). An object can only be immutable if all
> its embedded @mutable members are marked as shared.

That sounds rather weird considering immutable data neither needs nor
synchronization nor CPU cache reloading and @mutable shared one needs both.