Tuple enhancement

[Sebastiaan Koppe via Digitalmars-d]

On Sunday, 16 October 2016 at 13:58:51 UTC, Andrei Alexandrescu 
wrote:
> I was thinking it would be handy if tuples had a way to access 
> a field by name at runtime. E.g.:
>
> Tuple!(int, "a", double, "b") t;
> string x = condition ? "a" : "b";
> double v = t.get!string(x, 3.14);

That would mean that tuple then needs to keep the strings around 
- taking up space. That plus the fact that the following code is 
equivalent (obviously):

Tuple!(int, "a", double, "b") t;
double v = condition ? t.a : t.b;

Why this addition? What does it enable?