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!
It'd be interesting if you could investigate the case of
non-trivial lambdas, where inlining the lambdas is not
profitable. Perhaps easiest if you call opaque (declaration-only)
functions in the visit list.
Conclusion, performance-wise:
- SumType is great
- std::visit is OK'ish
- D Algebraic is terrible
Do you agree?
cheers,
Johan
