challenge #3 - Parallel for loop

[Andrei Alexandrescu (See Website For Email)]

janderson wrote:
> I would like to be able to run a for loop in parallel, using syntax like:
> 
> //example 1
> int sum = 0;
> foreach_parallel(int a; array)
> {
>   sum += array[a];   //This could be anything
> }

This challenge "is not like the others". Unfortunately parallelization 
like the above is not going to be done soon. Parallelizing arbitrary 
serial code is an active research topic that has not been settled.

In particular, notice that even your simple example requires serious 
smarts from a compiler, because it features dependencies across the 
loop: sum can be apparently updated on the n+1'th iteration only after 
it has been updated on the n'th iteration.


Andrei