Re: automem v0.0.7 - C++ style smart pointers using std.experimental.allocator

[Kagamin via Digitalmars-d-announce]

On Wednesday, 12 April 2017 at 13:32:36 UTC, Stanislav Blinov 
wrote:
Syntax is not the core of the issue, it's not about just 
marking a destructor as shared. Making RefCounted itself shared 
would require implementing some form of synchronization of all 
the 'dereference' operations, including assignments. I.e. if we 
have some shared(RefCounted!T) ptr, what should happen when two 
threads simultaneously attempt to do ptr = 
shared(RefCounted!T)(someNewValue) ? Should a library 
implementation even consider this? Or should such 
synchronization be left to client's care? It seems like in this 
regard shared(RefCounted!T) would be no different from 
shared(T*), which brings me to the next point.

If we can control memory layout, we can do what shared_ptr does 
and couple the reference counter with the object, then we can 
have just one pointer:

struct RefCounted(T)
{
  struct Wrapper
  {
    int count;
    T payload;
  }
  Wrapper* payload;
}