[naasking]

> Could you not get most of the benefits of ADTs using structs + unions + enums?

The modelling aspects can be simulated, yes, but that's barely half of the benefits of ADTs. Pattern matching is a big ergonomic benefit.

[cryptonector]

TFA gets pattern matching.

The critical thing is that the compiler (or macro system) needs to check that you've checked all the alternatives.

[naasking]

Yes TFA is pretty close, but note that it's not just "structs + unions + enums" getting you "most of the benefits", which is what I was responding to. There's a buttload of macros hiding allocation and switch statements.