Re: [boost] [coroutine] new versions

Subject: Re: [boost] [coroutine] new versions
From: Oliver Kowalke (oliver.kowalke_at_[hidden])
Date: 2012-10-11 02:20:38

> I would
> like to see the coroutine-function with a void return type. Or have an
> option for that.

I've had such a version but I dropped it because for detecting the completeness of the coroutine would require an extra jump (return from last jump-function and calling return in the coroutine-fn).
And this makes the implementation for iterators very painful:

void fn( coroutine<void(int)> & c) {
    c( 1);
    c( 2);
}

The iterator would be required to be incremented three times. And std::distance would return 3 instead of 2.

> As for output iterators, I see that it's currently only supported for
> coroutines with void return type and arity of 1. If a coroutine has a
> non-void return type, output iterator can still be defined, just
> ignore the return values.

I would keep the interface simple - introducing such an iterator would be a source of confusion (why is the return type ignored etc.). The users could still use such coroutines but without an iterator interface.

regards,
Oliver