I don't think that the precedent matters that much in this situation, as to whether people would dismiss such an idea or not.

People can dismiss language ideas and concepts that "have been known and used for many decades" just the same.

For a trivial example: significant whitespace.

So, e.g. "Lisp has had that since forever" is not a guarantee people would be OK with it, unless they also like Lisp - not to mention they might not even know about it in Lisp.

As for C++, many people consider templates - at least as implemented - a bad idea. So some people knowing that it existed in C++ already, and considering it a bad idea to have in Zig is not contradictory.

Sure but then it's like... for example, if you land rockets and your advertisement says "People told me it couldn't be done!", then fair enough. But if you, say, build an electric car and your advertisement says "People told me it couldn't be done!", then ... who exactly have you been talking to?

The phrase "They said it couldn't be done!" is an evocative proxy for technological novelty. If the experts are not representative, the claim of novelty will be misleading.

yeah, though in this case they didn't say "it can't be done" or "was never done" - just that it is a "really dumb idea". At least that's what the post claims they said.

Which is precisely my point. As one other commenter said: "who have you been talking to?". Executing code at compile-time is a great idea in general, maybe those experts were talking about a very particular problem? It's not clear.

>Executing code at compile-time is a great idea in general

Well, it did create a big mess and overhead in C++ for one (not to mention adding another turing-complete language on top of it)...

Ah but that's an implementation and design choice issue. It's like saying "classes are a bad idea because implementing them in pure C is cumbersome".

Well, to criticize something people start (and, often, end) on concrete examples they've seen it in practice. And for "compile time code generation" C++ templates are an example they'd be familiar with (perhaps the canonical one, as more people know C++ than Lisp).