3 ms·

> the degree to which you have to ask yourself if you want to use String or if you want to use &str In practice, there isn’t a ton of thinking to do about this

> the degree to which you have to ask yourself if you want to use String or if you want to use &str In practice, there isn’t a ton of thinking to do about this: if it’s a struct, you want String. If it’s a function parameter, you want &str, and if it’s a function’s return type, you want String. Doing that until you have a reason not to is the right call 95% of the time, and 4% of that last 5% is “if the return type is derived from an argument and isn’t changed by the body, return &str. It does take some time when you’re learning, but once you get over the hump, you just don’t actively think about this stuff very much. Google’s research says Rust is roughly as productive as any other language there, so far. That doesn’t mean it’s universally true, but it’s also some evidence it’s not universally false.

School-Cotton 2y ago
If you write Rust like this (insisting that structs always fulfill 'static) you will end up unnecessarily cloning memory way more than you would in a GC'ed language. In GCed languages strings get allocated once when you need them, get referred to wherever you want, however many times you want (with no new calls to the allocation subsystem), and are freed once when you don't need them anymore, with minimal thought or intervention on the programmers part. Rust is absolutely not like this at all. I agree with the overall idea that people exaggerate the difficulty of Rust, but come on, this is an exaggeration way too far in the other direction.
- steveklabnik 2y ago
  That’s why it’s “until proven otherwise.” As you gain experience you can be more subtle about it, and you gain more intuition, but it’s just not that big a deal until you demonstrate it’s a big deal. I rarely type clone(). Even with this advice, you won’t clone super often. And when you do, it’s a signal sometimes that maybe you can do better, but it’s just not a big cognative burden.
rc00 2y ago
> Google’s research says Rust is roughly as productive as any other language there, so far. That doesn’t mean it’s universally true, but it’s also some evidence it’s not universally false. You shouldn't call this evidence but instead marketing. It was thoroughly debunked for the nonsense that it was in many places such as this: https://www.youtube.com/watch?v=vB3ACXSesGo https://www.youtube.com/watch?v=vB3ACXSesGo

School-Cotton 2y ago

If you write Rust like this (insisting that structs always fulfill 'static) you will end up unnecessarily cloning memory way more than you would in a GC'ed language. In GCed languages strings get allocated once when you need them, get referred to wherever you want, however many times you want (with no new calls to the allocation subsystem), and are freed once when you don't need them anymore, with minimal thought or intervention on the programmers part. Rust is absolutely not like this at all. I agree with the overall idea that people exaggerate the difficulty of Rust, but come on, this is an exaggeration way too far in the other direction.

steveklabnik 2y ago
That’s why it’s “until proven otherwise.” As you gain experience you can be more subtle about it, and you gain more intuition, but it’s just not that big a deal until you demonstrate it’s a big deal. I rarely type clone(). Even with this advice, you won’t clone super often. And when you do, it’s a signal sometimes that maybe you can do better, but it’s just not a big cognative burden.

rc00 2y ago

> Google’s research says Rust is roughly as productive as any other language there, so far. That doesn’t mean it’s universally true, but it’s also some evidence it’s not universally false. You shouldn't call this evidence but instead marketing. It was thoroughly debunked for the nonsense that it was in many places such as this: https://www.youtube.com/watch?v=vB3ACXSesGo https://www.youtube.com/watch?v=vB3ACXSesGo