Concurrency.

[Debdata]

Hi,

I have been evaluating D for the past week, and have some concerns regarding the No Default sharing rule. I have been reading the D book by Andrei as
well. This particular feature has been very confusing to me as I come from the c++ world.

I agree that message passing and resource hiding are a great way to go for a lot of cases, but there are an equally large (Larger?) number of cases
that would benefit from global sharing. Especially when threading for performance rather than convenience. The cutting edge of high performance
threading is really the task stealing approach. See intel's TBB, cilk, etc. Implementing things like that would become unnecessarily verbose as most
things will be shared and we have to keep tagging.

Unless I am missing something. :D

-Debdatta Basu