alt Hacker NewsAre there any plans to more seriously develop the standard library in Rust? Or is the plan to remain in this status quo where users of Rust import nonsense and the dependency tree explodes (or users are forced to invent their own wheel?).
Are there any comparisons between the state of the stdlib in C++ vs. Rust? I’d think that would serve as an excellent jumping off point to start chipping away.
Replies
The idea that Rust has a small standard library is a weird meme. Rust has an enormous standard library. Look at any Rust release and you'll see dozens of new library APIs added, and consider that Rust has about nine releases a year, meaning that Rust adds over a hundred APIs per year, and has consistently for the past ten years. Rust frequently adds things that obviate popular crates, most recently the cfg_if crate was made redundant by the new cfg_select macro. And half of every dependency graph that people wrong their hands over are actually first-party external crates provided by either the Rust organization itself or by known contributors to the project. When people say that Rust has a small standard library, mostly they seem to just mean that it doesn't include a webserver.
The standard library is not versioned, so any API*/behaviour there must be maintained forever. When you put it in a separate crate, you can make better interfaces or be displaced by a better crate, while old code still compiles against the version it was written for. So even code effectively maintained within rust teams (hashbrown, rand, regex) may be in separate crates, std is specifically for OS abstraction and a shared type vocabulary.
That doesn't mean you jump to importing nonsense or trivial dependencies. The top hundred are efficient, well-designed crates of the quality you'd expect in a large std like Go or Swift, sometimes even higher as people can write better implementations that they otherwise wouldn't (or wouldn't be used over std). And those languages make breaking changes! C++ is mostly stable, so it's full of junk like <regex> or just unordered_map. Rust managed to wholesale reimplement HashMap 6 months after SwissTable released, like it is also easier to express this level of encapsulation, but that's part of countless design/interface decisions made deliberately to not constrain forwards compatibility, including a smaller std.
However, that's no excuse to have a worse developer experience in this area. We need better tools to vet and communicate the quality of a crate and its supply-chain, like community-curated or even additional org-maintained crates, and maybe a handful delivered precompiled in the default rustup distribution which can change over time. I don't think they need to be added to std itself though