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Only if it is repeatable. We have no information on what they learned in the two failed attempts - it is likely that they learned from the failures and started
by bluGill 10mo ago
Only if it is repeatable. We have no information on what they learned in the two failed attempts - it is likely that they learned from the failures and started other architectural changes that enabled the final one to work. As such we cannot say anything about this.
Rust does have some interesting features, which restrict what you are allowed to do and thus make some things impossible but in turn make other things easier. It is highly likely that those restrictions are part of what made this possible. Given infinite resources (which you never have) a C++ implementation could be faster because it has better shared data concepts - but those same shared data concepts make it extremely hard to reason about multi-threaded code and so humanly you might not be able to make it work.
- steveklabnik 10mo agoWe do have some information: https://youtu.be/Y6SSTRr2mFU?t=361 https://youtu.be/Y6SSTRr2mFU?t=361 (linked with the specific timestamp) In short, the previous two attempts were done by completely different groups of different people, a few years apart. Your direct question about if direct wisdom from these two attempts was shared, either between them, or used by Stylo, isn't specifically discussed though. > a C++ implementation could be faster because it has better shared data concepts What concepts are those?
- bluGill 10mo ago> What concepts are those? Data can be modified by any thread that wants to. It is up to you to ensure that modifications work correctly without race conditions. In rust you can't do this (unsafe aside), the borrow checker enforces data access patterns that can't be proved correct. Again let me be clear: the things rust doesn't allow are hard to get correct.
- steveklabnik 10mo agoI mean, data races are undefined behavior in C++ the same way that they are in unsafe Rust. The languages are equivalent there.
- bluGill 10mo agoOnly if there is a data race - if there is no data race C++ lets you do it. Rust doesn't let you do things that don't have a race but cannot be proven within the context of rust to not have a data race.
- steveklabnik 10mo agoIn safe Rust, yes, you must prove it. But in unsafe Rust, it's up to you. It's the exact same thing.