> No, that's an uncharitable reading. I never claimed that IDEs will automagically understand higher level semantics. So what are you saying? Because that's wh

> No, that's an uncharitable reading. I never claimed that IDEs will automagically understand higher level semantics. So what are you saying? Because that's what I'm honestly understanding from your post. That somehow this feature being a Rust macro means that it cannot be as good as if it was a first class feature. You are making this claim in general, as if first class features are always strictly better than user-defined features, yet this claim isn't true, and you haven't mention any particular aspect of automatic differentiation for which this is the case. Swift doesn't have proc macros, so they have to make the feature first class. For languages with proc macros, the question that one should be asking is: what value does a first class language feature adds over just using a proc macro.