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> It has some syntactic sugar for it in the form of a compiler-enforced RAII, but that is still manual memory management for all practical purposes. Then you'

> It has some syntactic sugar for it in the form of a compiler-enforced RAII, but that is still manual memory management for all practical purposes. Then you've got a different definition of "manual" than mine. Manual means that developer has to insert calls to allocate / deallocate memory and that the developer is responsible for proving the correctness of those calls. Automated means those calls are done by the runtime or by the compiler automatically, and the compiler makes sure they are correct. In case of Rust, those calls are inserted automatically by the compiler. > memory/ownership details leak into public APIs The fact that ownership is a part of public API is a good thing, similarly how it is a good thing to specify an argument is an integer and not a string. > There are plenty of managed languages with these, ML, OCaml, Haskell, Scala. I referred to the ones mentioned in the above comment, which mentuoned Java/Go/Python. Haskell/Scala/Ocaml/ML are quite niche even compared to Rust these days. But even though Haskell / Scala might get close on some type-system features, they don't offer similar experience as Rust in other areas. Haskell is more restrictive in terms of managing state than borrow-checker, and Scala tooling / compile times has been always horrible. > Rust only addresses problems related to data races, not as an example. All the other race conditions are still on the table. This is like saying a statically typed language doesn't stop you from putting a string telephone number into a string surname field. Sure it doesn't. But despite that, the value of static types is hard to overestimate. In practice, the borrow checking + RAII + Send/Sync rules can be used to make the other types of concurrency problems very unlikely by properly modeling the APIs. Sure, no language can protect from all concurrency problems in general, but at least Rust gives you some good tools. For instance it is trivial to forbid concurrent access to something that shouldn't be accessed concurrently and let the compiler enforce that. Now try enforcing that in your "business oriented language of choice". In my experience the majority of concurrency related problems in real large-scale software development happen when some code not designed to handle concurrency accidentally becomes executed concurrently because developers don't realize something is shared and mutated at the same time. Another type of common issue is with communicating concurrent threads of execution, when one sends a message but the receiver is not there on the other end because of premature exit e.g. due to error, leading to a deadlock. Rust protects from those really well.

kaba0 3y ago
> The fact that ownership is a part of public API is a good thing A libraries next version which switches up some internal representations memory handling should ideally not mess up your application, but it also mandates a higher refactor rate when you are only working within your application’s boundaries. These are worthwhile tradeoffs for the niche rust is targeting, but not for every use case. I’m not saying Rust is a bad language, I really like using it for its intended niche of complex applications where absolute control is needed, like a browser engine. But it is not a panacea and I would definitely not choose it for a CRUD webapp.
- pkolaczk 3y ago
  > A libraries next version which switches up some internal representations memory handling should ideally not mess up your application It doesn't have to because internal memory representation can and should be abstracted out, and Rust gives a plethora of tools to do that. Your argument works against against static typing in general. The next version changes the address representation from String to Address (in managed language) and messes up your app. That's the same thing.
  - kaba0 3y ago
    > Your argument works against against static typing in general I don’t think this argument works. Ad absurdum a very strong type system would even specify the implementation itself, making any change breaking — is that good? No, it isn’t as the useful property of the type system is no longer there. I don’t agree that this usefulness line is behind “ownership annotations” — that’s what you would have to convince me of.
  - foldr 3y ago
    If version 1 of your library has a function that returns a reference to T, then that constrains your choices of implementation for the underlying data structures containing Ts more than they would be constrained in a garbage-collected language. So unless there is to be a ban on functions returning simple references, Rust is always going to be a little less flexible in this respect. That is fine and expected given the overall design goals of the language, but there's no point pretending that it's not the case. The simplest concrete example, I guess, would be a function that returns &'str. There are plenty of Rust APIs out that have functions with this type signature.

kaba0 3y ago

> The fact that ownership is a part of public API is a good thing A libraries next version which switches up some internal representations memory handling should ideally not mess up your application, but it also mandates a higher refactor rate when you are only working within your application’s boundaries. These are worthwhile tradeoffs for the niche rust is targeting, but not for every use case. I’m not saying Rust is a bad language, I really like using it for its intended niche of complex applications where absolute control is needed, like a browser engine. But it is not a panacea and I would definitely not choose it for a CRUD webapp.

pkolaczk 3y ago
> A libraries next version which switches up some internal representations memory handling should ideally not mess up your application It doesn't have to because internal memory representation can and should be abstracted out, and Rust gives a plethora of tools to do that. Your argument works against against static typing in general. The next version changes the address representation from String to Address (in managed language) and messes up your app. That's the same thing.
- kaba0 3y ago
  > Your argument works against against static typing in general I don’t think this argument works. Ad absurdum a very strong type system would even specify the implementation itself, making any change breaking — is that good? No, it isn’t as the useful property of the type system is no longer there. I don’t agree that this usefulness line is behind “ownership annotations” — that’s what you would have to convince me of.
- foldr 3y ago
  If version 1 of your library has a function that returns a reference to T, then that constrains your choices of implementation for the underlying data structures containing Ts more than they would be constrained in a garbage-collected language. So unless there is to be a ban on functions returning simple references, Rust is always going to be a little less flexible in this respect. That is fine and expected given the overall design goals of the language, but there's no point pretending that it's not the case. The simplest concrete example, I guess, would be a function that returns &'str. There are plenty of Rust APIs out that have functions with this type signature.