rust-playground VS rustfmt

> The biggest annoying magic I found with respect to Box (and other std containers like Rc) is that they’re the only ones capable of storing fat dyn pointers. You can’t construct a hybrid_rc::Rc like you can with Box/Rc.

Anything can store fat dyn pointers, they're just like any other type in that regards.

Constructing them for a specific trait is easy and possible on stable (e.g. adding a `as_debug(MyBox) -> MyBox` method).

Making it possible to construct them for any trait is special to the built in pointers... on stable. On nightly with unstable features it's possible (and easy) to make any smart pointer type do this.

Code examples:

https://play.rust-lang.org/?version=nightly&mode=debug&editi...

That would be true if you used `Vec::clear` too, it doesn't allocate a new vector. My point was that you still end up running Drop implementations with RepeatedField, just not all at once. See https://play.rust-lang.org/?version=stable&mode=debug&editio...

That's a valid Unix path, but rust's quoting does nothing to stop it: https://play.rust-lang.org/?version=stable&mode=debug&editio...

Self-referential structs work fine in Rust and always have.

https://play.rust-lang.org/?version=stable&mode=debug&editio...

The compiler will correctly prevent you from moving the value.

The other way to have a struct that starts out as non-self-referential and then becomes self-referential can be achieved with `unsafe` and `Pin::new_unchecked`, which is how `async {}` is handled.

In rust as currently stands: https://play.rust-lang.org/?version=stable&mode=debug&editio...

On the other hand, both this wrapper and yours are counterproductive if the element size is dynamic (e.g. perhaps you're dealing with some nonsense like:)

    struct ITableColumn {

Overflow checks turn into two's compliments' wrapping, but that's only considered acceptable because bounds checks are not turned off.

https://play.rust-lang.org/?version=stable&mode=release&edit...

I have no idea what you're talking about, but it sounds unnecessarily complicated and why I don't use Rust for any serious work.

This demonstrates the ABA problem in safe Rust: https://play.rust-lang.org/?version=stable&mode=debug&editio...

Substitute the sleep with a combination of doing computation/work and the OS thread scheduler, and you can see how the bug surfaces.

You can also try Rust online using the Rust playground: https://play.rust-lang.org/

(Click ... beside build to get assembly) https://play.rust-lang.org/?version=stable&mode=release&edit...

Unfortunately the go playground doesn't seem to support emitting assembly?

The author provides very surface-level criticism of two Rust tools, but they don't look into why those choices were made.

With about five minutes of my time, I found out:

wrap_comments was introduced in 2019 [0]. There are bugs in the implementation (it breaks Markdown tables), so the option hasn't been marked as stable. Progress on the issue has been spotty.

--no-merge-sources is not trivial to re-implement [1]. The author has already explained why the flag no longer works -- Cargo integrated the command, but not all of the flags. This commit [2] explains why this functionality was removed in the first place.

Rust is open source, so the author of this blog post could improve the state of the software they care about by championing these issues. The --no-merge-sources error message even encourages you to open an issue, presumably so that the authors of Cargo can gauge the importance of certain flags/features.

You could even do something much simpler, like adding a comment to the related issues mentioning that you ran into these rough edges and that it made your life a little worse, or with a workaround that you found.

Alternatively, you can continue to write about how much free software sucks.

[0]: https://github.com/rust-lang/rustfmt/issues/3347

[1]: https://github.com/rust-lang/cargo/pull/10344

[2]: https://github.com/rust-lang/cargo/commit/3842d8e6f20067f716...

The new style still supports single line let-else, and there is a configuration parameter to make it be on one line also for longer lines.

It seems there is an issue about this dating all the way back from 2018 but yet it still hasn't been fixed.

However since 4179 recent versions should merge configuration files. Not sure what the details / specifics are but if just ignoring the file entirely is not good enough you might give it its own directory and rustfmt.toml file and see if that works.

Could this be be #3863 - Gives up on chains if any line is too long? It might not be, because I can't see a specific "line" that's too long to format, but there's more detail about the exact problem in the issue.

Rustfmt is a tool that formats Rust code in compliance with style guidelines. Its name precisely reflects its purpose. To install rustfmt, you can run rustup component add rustfmt. Once installed, you can execute cargo fmt to format Rust code in your workspace. If you require further information, you can visit rustfmt’s GitHub repository.

code must be formatted with rustfmt.

Yes, some cases are not yet supported (https://github.com/rust-lang/rustfmt/issues/4914).

Just FYI, the let-else suggestions will only work until rustfmt settles on a format for it. So you may be surprised when this happens and it suddenly changes.