Tuple DIP

[Steven Schveighoffer]

On 1/12/18 5:44 PM, Timon Gehr wrote:
> As promised [1], I have started setting up a DIP to improve tuple 
> ergonomics in D:
> 
> https://github.com/tgehr/DIPs/blob/tuple-syntax/DIPs/DIP1xxx-tg.md

Awesome! I can say I felt a lot more comfortable with the trailing-comma 
syntax after our last discussion :)

> Before going ahead with it, I'd like some preliminary community input:
> 
> - I'm not yet completely satisfied with the DIP.
>    (See section "Limitations".)
>    Please let me know suggestions or further concerns you might have.

In the section discussing the breaking changes with proposal 3, you say:

"The DIP author cannot see an obvious mitigation other than keeping 
std.typecons.Tuple and core.object.__Tuple separate instead of aliasing 
them."

Well, what if std.typecons.Tuple can detect whether it's being used in a 
non-compatible way, and falls back on the original implementation? That 
is, when it works, it's an alias to object.__Tuple/__tuple, when it 
doesn't work, it's the old std.typecons.Tuple/tuple.

I would expect it not to be that difficult to detect, but you don't 
specify exactly what the problems are so I'm not 100% sure I know what 
you are talking about :) An example would help.

-----

About proposal 2, you say it's inspired by the conversation we had in 
the forums. I remember the discussion, but I'm not seeing the 
relationship with Proposal 2.

I also am not sure about the example. It defines some function max, and 
then never uses it. I'm assuming somewhere there's a typo? In fact, I 
think the example would compile today as it doesn't use any tuples (I 
think), so I don't see the reason for it.

-Steve