DIP54 : revamp of Phobos tuple types

[bearophile]

H. S. Teoh:

> Personally, I'm for simplifying the core language and moving
> non-essentials out to the standard library

How do you define "essential"?
- Frequently used;
- The compiler can compile it as efficiently as handwritten code;
- Has a sufficiently clean semantics, that is most times the one 
that's desired;
- You can't (yet) implement its main purposes with library-code;
- Sufficiently important.
- etc.

Bye,
bearophile