Daily Rust

@NeoSmart What is a better alternative?

@rustoftheday This is a terrible crate that should not be used outside of extremely, *extremely* niche situations. It bust waits and each consumer will take 100% of a core waiting for messages. DO NOT USE.

Want true pub-sub semantics in Rust? The Bus crate gives you SP→MC broadcast semantics. Crossbeam’s MPSC supports multiple consumers, but it round-robins messages, not exactly what you want for fan-out. crates.io/crates/bus

@nother_pleb Agree to using it as a safety net, but not as a primary way of handling errors.

@rustoftheday Not really, catch_unwind is a great solution for network services, you put on the top level to catch and report a server error so it doesn't take your whole instance down. It's a safety net, not error handling per se. Also, panics must be safe, unsafe code must be ready to handle

🦀 #Rust Tip #119: Some folks suggest using std::panic::catch_unwind as a solution to the recent unwrap() panic that stopped the internet. In my opinion this is an anti-pattern, some thoughts: - bypasses memory safety constraints (e.g., panic in unsafe block)

@_Felipe Great idea if you want to jump straight into undefined behavior. One of the tenets in Rust is to prevent undefined behavior. In the case of unhandled errors (unrwap()) the sound option is to stop execution. There is unwrap_or_default() though...

We need an .unwrap_in_debug_builds_but_just_carry_on_in_release_builds() function in Rust to stop these incidents. I have recently caused problems with a panic that would be informative in debug builds during testing but didn’t really have to fire in production.

#119 (contd.) - imposes runtime cost by stack walking - encourages using panic for control flow - many APIs are not unwind-safe - cannot catch "fatal" errors such as out-of-memory

You generally want a Clippy linter like this one in your Rust production code

@LundukeJournal We should note it wasn't a memory issue but unsound handling of an error state.

September, 26: Cloudflare rewritten in “memory safe” Rust. The change is touted as “faster and more secure” because of Rust. blog.cloudflare.com/20-percent-int… November, 18 (53 days later): Cloudflare has a massive outage, which took down large portions of the Internet, because of a memory error… in that Rust code. blog.cloudflare.com/18-november-20…

@deviant_studio @grok They were basically calling a function that either returns a successful result or an error. Production code would normally handle the error case. Calling unwrap() will panic and halt execution if there was an error.

@rustoftheday @grok can you explain? what is unwrap(). what the hell happened with cloudflare?

Don't use unwrap() in your production code, boys and girls! 😃

@ChShersh @jino_rohit the naked pointers burn the eye

@jino_rohit Brother, I see C, not C++ Throw some templates, lambdas and smart pointers there.

Learning C++ is super rewarding and humbling. Today I'm working through the Byte Pair tokenizer from karpathys code and port to C++. I'm taking it as slow as I can to test, write and re-write everything.

@renzocarbonara are you referring to "fat enums" 🤣😇?

🦀 #Rust Tip #118: Result::and_then lets us chain operations that return Result, bypassing nested pattern matching. Although the ? operator often accomplishes the same, and_then allows us to remain in a more functional "combinator style".

Animate anything with Rust 🦀 🌀 KramaFrame — A simple, generic, and flexible keyframe animation library. ⚡ Manage multiple animations, apply easing functions, and map progress to any range. 🐁 Includes a terminal demo w/ @ratatui_rs ⭐ GitHub: github.com/CosmoBunny/kra… #rustlang #animation #library #programming #terminal #ratatui #tui

@yotstack There is a .then() method for async futures in Rust as well, but mostly .await is sufficient.

@rustoftheday I wondered why Rust would not have something similar to Promise.then as in Javascript

This is gold if you're using async Rust 💯 🌀 channels-console — A TUI dashboard for inspecting std/tokio/futures/crossbeam channels. 📊 Watch messages, queue depth, throughput & memory usage live. 🦀 Written in Rust & built with @ratatui_rs ⭐ GitHub: github.com/pawurb/channel… #rustlang #ratatui #tui #async #concurrency #tokio #debugging

@ChShersh I see what you are doing 😀Just give in to the urge and switch to #rustlang

Spent more than 15 minutes writing a simple Stack Machine evaluator in C++ using std::visit and std::variant. Unacceptable. Time to end this day.

@barettorein @axiosopher Not sure I follow 100%, if statements don't need round parens, for example. Also, try a C++ closure auto add = [&sum](int v){ sum += v; }; ampersand and all types of possible parens Rust: let mut add = |v| { total += v; };

@rustoftheday @axiosopher Rust is much messier than C++ syntax wise, far more ampersands than i'd like and it feels like it needs a metric fuckton of round parens even if sometimes you can avoid them maybe

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