Out of order execution

[Andrea Fontana via Digitalmars-d-learn]

On Thursday, 16 June 2016 at 01:57:19 UTC, Joerg Joergonson wrote:
> Suppose I have a loop where I execute two functions:
>
> for(...)
> {
>    if (x) Do1(x);
>    if (y) Do2(y);
> }
>
> The problem is, I really always want to execute all the Do2's 
> first then the Do1's. As is, we could get any order of calls.
>
> Suppose I can't run the loop twice for performance 
> reasons(there is other stuff in it) and I don't want to store 
> the state and call info then sort them out afterwards.
>
> Is there an efficient lazy way to make this happen?

Something like: https://dpaste.dzfl.pl/79b77c934825 ?