Shared - Another Thread

[Stefan Koch]

Hi,

reading the other shared thread  "shared - i need to be 
useful"(https://forum.dlang.org/thread/mailman.4299.1539629222.29801.digitalmars-d@puremagic.com)

let me to an important realisation concerning the reason 
shareding data across threads is so unintuitve and hard to get 
right.
The reason is that sharing in the real world has nothing to do 
with using something and the same time.
For example: If I share my flat with another person, that person, 
while occupying the same flat as me, cannot actually occupy the 
same space. It is physically impossible.

In other words sharing does not mean for multiple entities to own 
something it's rather about diving and managing the (temporary) 
ownership of fragments.

Therefore if ownership is unclear sharing is impossible.
The safest default for something shared with unclear ownership is 
to view it as untouchable/unreadble/unwritable until ownership is 
established.