DIP54 : revamp of Phobos tuple types

[John Colvin]

On Monday, 30 December 2013 at 08:39:55 UTC, Dicebot wrote:
> On Monday, 30 December 2013 at 06:42:56 UTC, Andrei 
> Alexandrescu wrote:
>>> If it is you judgement, let it be so. I prefer to start 
>>> working on
>>> implementation whatever it is as opposed to endless 
>>> discussion. What is
>>> your opinion about defining general guideline to use packs 
>>> over nested
>>> templates for multi-list algorithms (another disagreement 
>>> between me and
>>> Jakob)?
>>
>> I think an argument advocating a bunch of changes that add 
>> chaff to code that works very well would have a hard time 
>> geting off the ground. Use the right tool for the job - that's 
>> why we're providing two of them.
>
> It is not related to any existing code as there are no 
> multi-list templates in std.typetuple right now. What I am 
> speaking about is defining new ones in two possible ways:
>
> template Equals(T1...)
> {
>     template To(T2...)
>     { ... }
> }
>
> vs
>
> template Equals(alias T1, alias T2)
>     if (isTemplateArgumentPack!T1 && isTemplateArgumentPack!T2)
> {
> }
>
> I think default Phobos style should be the latter while Jakob 
> seems to favor the former. Judgement of uninterested party is 
> welcome.

The latter is the style I went for. However, with 
TemplateArgumentPack as a struct, the alias' aren't necessary. 
It's just a type :)