Why four definitions of std.meta.Replace?

[Adam D. Ruppe]

On Monday, 25 May 2020 at 01:43:01 UTC, Andrei Alexandrescu wrote:
> Why all this?

Until semi-recently, you could not pass a built-in basic type to 
an `alias` param. I don't recall when that was changed, I think 
it last year, but surely the Phobos implementation predates that 
enhancement.

And you could use the ... before but that was perhaps too 
permissive. Or maybe the original author just didn't like that 
style.

But with alias accepting keyword types now, I imagine a LOT of 
phobos could be simplified to use it.