Tuples citizenship

[Jonathan M Davis]

On Friday, March 02, 2012 09:31:14 kennytm wrote:
> Jonathan M Davis <jmdavisProg at gmx.com> wrote:
> > That's assuming that you're passing all of the pieces of the tuple to the
> > function. Often, that's not the case at all. Take the findSplit trio, for
> > instance. What are the odds that you're going to want to pass all of the
> > elements in the tuples that any of the return to another function? About
> > zero, I'd say. It's _much_ more likely that you're going to want to take
> > the results and then pass _one_ of them to another function. So, as it
> > stands, chaining with those functions just doesn't work unless you only
> > care about one of the results in the tuple.
> > 
> > - Jonathan M Davis
> 
> How does 'out' make chaining any easier? Suppose we have a `R3
> findSplit2(R1, R2, out R4, out R5)`, how to chain if we want to pass the R4
> to another function?
> 
>     R5 ignored;
>     R4 theRange;
>     findSplit2(haystack, needle, theRange, ignored);
>     return doSomething(theRange);
> 
> vs
> 
>     return doSomething(findSplit(haystack, needle)[1]);

True, you can't chain using the out parameters, but you _can_ chain using the 
return value, whereas if you have a tuple, you can't chain _at all_ unless you 
actually need all of the returned values (either as a tuple or expanded) or if 
you only need _one_ of the returned values, in which case you can use the 
subscript operator. So, you can definitely chain better without a tuple than 
with.

- Jonathan M Davis