As I know C++ now allows multiple dispatch for std::variant: https://en.cppreference.com/w/cpp/utility/variant/visit2.htm....

And std::variant is now a better choice for cases like in the article above, where previously inheritance was used to represent a closed set of possible subtypes.

This is a nice illustration of the expression problem, which the article itself points out toward the end. Multiple dispatch is a language-level way to solve it. Crafting Interpreters [1] has a very approachable Java-based chapter that also covers these patterns in detail.

[0] https://en.wikipedia.org/wiki/Expression_problem

[1] https://craftinginterpreters.com/representing-code.html

Would have been nice to mention that it's one thing that Julia seem to have gotten right.

if only programmers cared about functionality as much as syntax we'd be living in a lisp heaven

Thanks for posting this!

Just a quick note that this post is the first in a series: see https://eli.thegreenplace.net/tag/multiple-dispatch for the full series

Cue the smug Common Lisp weenies...

Oh, wait, that's me :-)