std.functional.memoize : thread local or __gshared memoization?

[Ola Fosheim Grøstad via Digitalmars-d]

On Saturday, 27 May 2017 at 16:19:06 UTC, Kagamin wrote:
> On Saturday, 27 May 2017 at 10:29:05 UTC, Ola Fosheim Grøstad 
> wrote:
>> Hm, I would think that using __gshared would not be affected 
>> by compiler improvements, since it would turn off 
>> optimizations that assume that the variable doesn't change 
>> between reads?
>
> Like volatile? Volatile doesn't work.

Volatile is different. Volatile means there can be side-effects 
from reads/writes, so the compiler cannot optimize out writes. 
This is for hardware registers.

> __gshared has purpose to behave like old good global variable 
> simply to provide a low level feature for a system language, if 
> you need something else, then use the right tool.

Doesn't make much sense to me.

If the semantics in C is that everything is typed shared then it 
should also be treated as such when D interfaces with C and C 
like type-semantics.