Opened the link. Saw my own comment. I'm still as confused today as I was then about how this was ever supposed to work—either the quoted code is wrong or there's some weird unstated interface contract. I gather from other issues the maintainers are uninterested in a semver break any time soon. Unsure if they'd accept a performance regression (even if it makes the thing actually work). So I feel stuck. In the meantime, I don't use per-layer filtering. That's a trap.

I've got a whole list of puzzling bugs in the tracing <-> opentelemetry <-> datadog linkage.

Agree, and I would add that a bad abstraction, the wrong abstraction for the problem, and/or an abstraction misused is far worse than no abstraction. That was bugging me in another thread earlier today: <https://news.ycombinator.com/item?id=47350533>

I'm not sure Rust's `async fn` desugaring (which involves a data structure for the state machine) is inlineable. (To be precise: maybe the desugared function can be inlined, but LLVM isn't allowed to change the data structure, so there may be extra setup costs, duplicate `Waker`s, etc.) It's probably true that there is a performance cost. But I agree with the article's point that it's generally insignificant.

For non-async fns, the article already made this point:

> In release mode, with optimizations enabled, the compiler will often inline small extracted functions automatically. The two versions — inline and extracted — can produce identical assembly.

5. In their "dessert" section, they talk about a problem with sort when the items are shallow clones. It's an example of a broader problem: they put something into an `ObservableVector` but then semantically mutate it via inner mutability (defeating the "observable"). You just can't do that. The sort infinite loop is the tip of the iceberg. Everything relying on the observable aspect is then wrong. The lesson isn't just "jumping on an optimization can lead to a bug"; it's also that abstractions have contracts.

That distinction is what I was getting at with "if that statement came from the third party (rather than the school district misinterpreting the raw data themselves)".

If the company just provided the raw data, they may be in better legal shape. But I'd say either they or the school administrator libeled the family. Maybe both. (Of course, I'm not a lawyer.) Even if the company did provide only the raw data, I wonder if libel is somehow implied in its contracted/intended use. And I'm really hoping for the legal bloodbath outcome, because this is unconscionable.

The family may not have time or money to pursue this, but there are lawyers who work on contingency or even pro bono, including the ACLU.