Want reasonable reference counting? Disable automatic sharing of immutable

[Elronnd]

On Tuesday, 16 November 2021 at 17:52:10 UTC, Andrei Alexandrescu 
wrote:
> At least in theory it could mark pages as read-only. Current 
> compilers do that for statically-initialized constant data, but 
> not for anything else.

Would require annoying bookkeeping for small allocations.  
Obvious route is on every allocation you unprotect/reprotect; 
that's slow.  Alternately you can make one rw mapping and one ro 
mapping; write the newly created data through rw space, but 
return a pointer to ro space.  But then you are technically not 
'immutable'.