Blog Post: Beating std::visit Without Really Trying

[Tobias Pankrath]

On Sunday, 6 October 2019 at 00:52:38 UTC, Andrei Alexandrescu 
wrote:
>> Anyhow, currently we would have to name it differently (e.g. 
>> dts - https://github.com/wilzbach/dts). Maybe the upcoming 
>> SAoC project will change this and allow multiple versions of a 
>> library to co-exist in a binary.
>
> Adding it as a new facility is a possibility, but only if the 
> challenges of keeping the existing interface are too large.

I just want to chime in as a returning D user, who stumbled upon 
Nullable, Typedef and Algebraic.

I think is is important to have high quality and well supported 
versions of these kinds of type constructors in the standard 
library, because to really shine support for them has to be 
pervasive. I could roll my own (or use some package from 
code.dlang.org), but one of the key features have to be that they 
'just work'. I want to std.conv.to them [1], use them in a json 
serialization library out of the box, etc, etc.

[1] https://issues.dlang.org/show_bug.cgi?id=11704