Callbacks in C++ using template functors (1994) (tutok.sk)

Heard about this watching Casey Muratori's "The Big OOPs" talk [0]. Thought it couldn't be _that_ Hickey, but turns out it was!

[0] https://youtu.be/wo84LFzx5nI?si=SBv1UqgtKJ1BH3Cw&t=5159

C++ was so much cleaner in the 90s, when it was still essentially "C with classes," which is how I like to use the language. Modern standards have turned it into an ugly mess.

Red flags for me when I see nonstandard functors in a c++ codebase (esp if the "glue" is in a setup function independent of the objects):

(i) Have they thought about the relative lifetimes of the sender and receiver?

(ii) Is the callback a "critical section" where certain side-effects have undefined behavior?

(iii) Does the functors store debugging info that .natvis can use?

(iv) Is it reeeeeeeally that bad to just implement an interface?

Related. Others?

Callbacks in C++ using template functors (1994) - https://news.ycombinator.com/item?id=18650902 - Dec 2018 (50 comments)

Callbacks in C++ using template functors – Rich Hickey (1994) - https://news.ycombinator.com/item?id=12401400 - Aug 2016 (1 comment)

Callbacks in C++ using template functors (1994) - https://news.ycombinator.com/item?id=10410864 - Oct 2015 (2 comments)

not sure why the title was renamed, but i thought this was interesting primarily because it's the early work of Rich Hickey, famous for making the Clojure language.

Doing this today I'd just have a std::function parameter and have callers pass in a lambda. I may use a third party std::function that doesn't have the weird copy semantics though