TWiR quote of the week

This is also an incredibly important shift when trying to write performant software. See also this great C++ talk:


apparently I wrote Building Git to explain a complex problem to rust devs who could then help me build it in rust

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&mut obj as *mut *mut c_void :metal:
i just hear scandinavian death metal reading that

Nick Gideo via Rust VST chat


it’s true that the more i look at other people’s unsafe code the more i relax at people questioning how much i use unsafe code

@Lokathor on the community discord


What does it mean to be an expert in Rust?

Understands lifetimes

u/aesamattki on reddit.

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Lol, my initial reaction was “It does. That’s why it outlives all the other lifetimes” :joy:


Thanks to the borrow checker, you can’t generally tell the difference between shallow and deep copies in rust unless the type happens to have interior mutability. This makes shallow copies the clear winner for the majority of use cases in rust, and so it’s simply not something the average rust author thinks about every day.

@ExpHP in Contracts of the Clone trait?

(Long, but I found it insightful.)


Python and Go pick up your trash for you. C lets you litter everywhere, but throws a fit when it steps on your banana peel. Rust slaps you and demands that you clean up after yourself.

Nicholas Hahn in One Program Written in Python, Go, and Rust


Imagine Rust failed, why did it fail?

A team developing a key piece of security infrastructure decided to use Rust, but due to the unforgiving nature of the compiler, the team ended up relying on “unsafe” too often, and the resulting released product had more flaws than the previous release. One specific version had an uninitialized memory bug which could cause spurious apparent USB messages. A USB-connected sensor affected by the bug was being used in a defense installation, and the incorrect message triggered an ML-based pattern recognition system to infer a higher-than-tolerable probability of an imminent attack. The team at the installation determined that such an attack was going to happen too quickly to allow for the normal queries up the chain of command, and instead took it upon their own initiative to launch countermeasures. The subsequent chain of events: strikes, counterstrikes, desperate reactions, etc, led to the eradication of all mammalian life from the surface of the planet. Eons later, the follow-up reptilian intelligence never developed strong static typing, and used Reptile-Perl to write their launch control software, resulting in their rockets always exploding before making it into orbit.

/u/steven807 on Reddit


Are we trying to steal the JVM’s “compile once run everywhere” concept?

No, we just borrow it mutably.

/u/llogiq re: Stabilization of wasm-wasi target announcement on Reddit


This post by @rubberduck203 should be the Mantra of Rust and Open Source:


Rust is 5 languages stacked on top of each other, except that instead of ending up like 5 children under a trenchcoat, they end up like the power rangers.


You can write safe C++, but you can not accidentally write unsafe rust.


So he went from 1000$ a month to 0 a month, by rewriting a script with Rust.

‘Rhymes’ on summarises the economical value of writing performant code, in An example of why performance matters (with Python and Rust).

“He” is André Arko, lead dev of Ruby’s Bundlr, who got a 230x speedup in rewriting his bundlr log-parser in rust.
I’d recommend mr. Arko’s piece to anyone: it really captures that incredulous feeling of empowerment people get from Rust :blush:


Yes, of course we don’t call Python an “unsafe language” - but if we don’t call Python an unsafe language, it’s unfair to conclude that Rust is unsafe, since Rust actually does a better (imo) job of segregating and controlling unsafety.

/u/NoraCodes in


“[that unsafe function] might actually be safe for all I know. Feel free to investigate further!” – Lokathor, on writing a Rust wrapper for SDL


You shoot yourself in the foot. Nothing happens to the foot because it wasn’t declared mutable #rustlang

Elena Nadolinski on Twitter.

Originally suggested by @SenojEkul.


Roses are red,
Rust-lang is fine,
cannot borrow `i` as mutable more than once at a time


@drXor from internals engaging in UB poetry.

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Perhaps a better way to explain this is: you cannot ever get a function pointer to an intrinsic.

The compiler will just throw a block of ice in your face.

nagisa on Zulip

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