Precise GC state

[Ola Fosheim Grøstad]

On Monday, 27 November 2017 at 07:09:25 UTC, Ola Fosheim Grostad 
wrote:
> But it kinda is missing the point that if it only is in a 
> single thread then it would typically only have only one 
> assignment. Shared_ptr is for holding a resource not for using 
> it...

Just to expand a bit on this: What is lost here is that what has 
been proposed for D is to have a RC solution to solve what Rust 
does with borrowed pointers. Not unlike Swift.

In C++ life time management of borrowed pointers is fully manual, 
so it relies on algorithmic design rather than a programming 
mechanism. Although for C++ there is upcoming wrapper-types to 
allow for separate static analysis tooling that is comparable to 
Rust.

The intended usage is not comparable. (In C++ you typically will 
have per-type or per-application RC, wrapped up where you need it 
by encapsulation and move-semantics.)