Want reasonable reference counting? Disable automatic sharing of immutable

[Walter Bright]

On 11/12/2021 11:16 AM, Steven Schveighoffer wrote:
> having immutable implicitly shared is stupid when it's obviously not. Like an 
> immutable stack variable, why should I have to worry about sharability there? 
> Should I even be able to share it with another thread, as the stack is easily 
> destroyed?

Mutability and lifetime are orthogonal attributes.