Blog Post: Beating std::visit Without Really Trying

[Meta]

On Saturday, 5 October 2019 at 02:59:58 UTC, Paul Backus wrote:
> I was curious how C++17's std::variant compared to the options 
> we have in D, like Algebraic and SumType, so I did a simple 
> comparison of the generated assembly for each of them. You can 
> read about it at the link below. And as you can probably guess 
> from the title, D comes out ahead, in the end.
>
> https://pbackus.github.io/blog/beating-stdvisit-without-really-trying.html
>
> This is my first attempt at sharing something like this, so any 
> comment or feedback is very much appreciated!

I'm not sure if you're aware, but funnily enough, I also wrote an 
article[1] on std::variant vs. the D alternative that references 
Matt Kline's article on std::visit. It seems we're really making 
getting our money's worth from his article.

I really enjoyed this - I think you're right in that it comes 
down to the complexity of implementation, and I suspect that C++ 
forced the developers of std::variant to choose between a usable 
API (usable, not good) and performance.

I've been trying to communicate this major selling point of D to 
my coworkers, but it's a real uphill battle. I haven't even been 
able to convince them that built-in unit tests are a killer 
feature.

As an aside, I actively use your sumtype library and for the most 
part find it very nice to use. Thanks for the great work.

1.https://dlang.org/blog/2018/03/29/std-variant-is-everything-cool-about-d/