sumtypes for D

[jmh530]

On Wednesday, 30 November 2022 at 00:10:47 UTC, H. S. Teoh wrote:
> On Tue, Nov 29, 2022 at 11:56:40PM +0000, Vladimir Panteleev 
> via Digitalmars-d wrote:
>> On Monday, 28 November 2022 at 09:27:11 UTC, Walter Bright 
>> wrote:
>> > I've written most of a DIP for one. Should I:
>> 
>> I really wish that instead of adding more language features, 
>> we would improve the language so that things like this are 
>> implementable *in* the language.
> [.[..]
>
> +1, I think this is a better approach.  If a library type can't 
> do what a built-in type does, then extend the language until it 
> can. As Andrei said in TDPL: "experience has shown time and 
> again that offering many magic types that are unattainable to 
> user code is a frustrating proposition and a sign of poor 
> language design" [TDPL, 2010 ed, p.239].
>
>
> T

I don't dispute this, but there's a bit of a gulf between saying 
it and it actually happening. There needs to be a specific list 
of things that need to be changed, preferably as bug reports, 
otherwise Walter will complain about it getting lost in old forum 
posts.