postmono const expression conditions
note that you’d also need to do a similar check for alignment, which is omitted for brevity
UPD: as @arjentix pointed out, this will also only work in cargo build/cargo test; the check will be skipped in cargo check
playground

a bit late to the party, but couldn’t pass this one
method resolution depends on compiler’s mutable internal state, which you can observe by calling a method on an integer literal
playground
Rust issue (two Zulip threads linked inside)
CI failures for naive fix

it compiles.
playground

you can have unnameable traits with accessible methods
playground
reference

my fix for this problem was merged and will be stable in rustc 1.81, unless something goes wrong
https://github.com/rust-lang/rust/pull/123043

match match is legal and can be occasionally useful

- playground
- real-world example from rust-analyzer
- people even do if if sometimes

thanks to @LennyLizowzskiy for suggesting this!

a slightly more fun slash cursed variation on a standard “enum-instead-of-bool” trick

playground
don’t use booleans — an explanation on why would you even want that

thanks to @Ddystopia_0 for inspiring this one!

parsing sequences (like dates or version strings) by matching on part index

playground
original example

thanks to @kanashimia for suggesting this one!

1.80 now warns on #[cfg(skip)], so here’s a workaround

playground
release notes about the warning

(also yay 300 subscribers!)

wrote down some thoughts about error handling, specifically a pattern that I call “progress pattern” (probably it has another name somewhere, but I’m not aware of it)
https://github.com/GoldsteinE/gh-blog/blob/master/error_progress/README.md
thanks to @meowaffle for reviewing this!

(btw, are y’all ok with breaking the format like this sometimes?)

check out the crate btw, it’s really cool
blog post

yay it’s stable!

mixed-site hygiene might be surprising

original blogpost (read it, it’s cool!)
playground

thanks to @alexpyattaev for suggesting this!

cyclic associated types are okay under lazy normalization / next solver
(you need ?Sized though, otherwise it tries to prove Assoc: Sized and fails)

godbolt
tracking issue

macros can close over their environment, “breaking” hygiene

playground

I’d like to give a link to documentation here, but I don’t think this is actually documented anywhere? neither reference nor TLBORM mention it as far as I can see

UPD: ferrocene specification

now I can give a link to documentation!

(nightly) reference
my PR to reference

I’m sorry, but we seemingly need to do the same exact thing again
the new draft is somewhat better, but it still has at least two issues:
— it requires explicit approval to host events that are not free to attend, which includes even non-commercial events, since renting a venue isn’t actually free
— its wording around modified versions prohibits forking the compiler to send a PR, since you’re publicly distributing a modified version under the trademarked name

announces:
https://blog.rust-lang.org/2024/11/06/trademark-update.html
https://foundation.rust-lang.org/news/rust-trademark-policy-updates/

policy draft:
https://drive.google.com/file/d/1hjTx11Fb-4W7RQLmp3R8BLDACc7zxIpG/view?usp=sharing

feedback form:
https://docs.google.com/forms/d/e/1FAIpQLSeU1Ocopa0v9UZn_ZSTkKQM7gqZIrt63lCFz-xtogcFHMtkAg/viewform?usp=sf_link

please, read the policy and use the form to file your concerns if you have any. (please, don’t send my concerns without reading the policy yourself, that’s just spam)