[wavemode]

Simply because Rust requires you to manage memory yourself. It provides conveniences like Drop to help you do this correctly, but it still makes things harder (when using unsafe) than having a garbage collector to just throw your allocations at.

Java and Python both have access to unsafe operations (via sun.misc.unsafe/ctypes) but Java is multithreaded, which requires extra care, whereas Python is not.

[ISV_Damocles]

`drop` is an optimization. You never have to call it if you don't want to, Rust will automatically free memory for you when the variable goes out of scope.

Rust won't let you do the wrong thing here (except if you explicitly opt-in to with `unsafe` as you note is also possible in other languages). The Rust compiler, when writing normal Rust code will prevent you from compiling code that uses memory incorrectly.

You can then solve the problem by figuring out how you're using the memory incorrectly, or you could just skip out on it by calling `.clone()` all over the place or wrapping your value in `Rc<T>` if it's for single-threaded code, or `Arc<Mutex<T>>` for multi-threaded code, and have it effectively garbage-collected for you.

In any case, this is orthogonal to safety. Rust gives you better safety than Python and Java, but at the cost of a more complex language in order to also give you the option of high performance. If you just want safety and easy memory management, you could use one of the ML variants for that.

[wavemode]

You don't really seem to be understanding the point I'm making, or perhaps don't understand what memory safety means. Or perhaps are assuming I'm a Rust newcomer.

> Rust won't let you do the wrong thing here (except if you explicitly opt-in to with `unsafe`

There is no "except if you" in this context. I'm talking about unsafe Rust, specifically. I'm not talking about safe Rust at all. Safe Rust is a very safe language, and equivalent in memory safety to safe Java and safe Python. So if that's your argument, you've missed the point entirely.

> In any case, this is orthogonal to safety.

No, it's not orthogonal - memory safety is exactly what I'm talking about. If you're talking about some other kind of safety, like null safety or something, you've again missed the point entirely.

> ... calling `.clone()` all over the place or wrapping your value in `Rc<T>` if it's for single-threaded code, or `Arc<Mutex<T>>` ...

This whole paragraph is assuming the use of safe abstractions. If you're arguing that safe abstractions are safe, then, well... I agree with you. But I'm talking about raw pointers, so you're missing the point here.

[ISV_Damocles]

You're moving the goalposts. Your original post had zero mention of unsafe Rust. You have now latched onto this as somehow proving Rust is less safe than Python and Java despite also mentioning how Java also has unsafe APIs you can use, which nullifies even your moved goalposts.

Btw, Python also has unsafe APIs[1, 2, 3, 4] so this doesn't even differentiate these two languages from each other. Some of them are directly related to memory safety, and you don't even get an `unsafe` block to warn you to tread lightly while you're using them. Perhaps we should elevate Rust above Java and Python because of that?

[1]: https://docs.python.org/3/library/gc.html#gc.get_referrers

[2]: https://docs.python.org/3/library/ctypes.html

[3]: https://docs.python.org/3/library/_thread.html

[4]: https://docs.python.org/3/library/os.html#os.fork

[wavemode]

No goalposts have been moved here. Rust is a programming language with both safe features and unsafe features. It is a totality.

And now you're linking me docs talking about things I already explicitly mentioned in my past comments.

You are so confidently ignoring my arguments, and so fundamentally misunderstanding basic concepts, that this discussion has really just become exhausting. I hope you have a nice day but I won't be replying further.

[pkolaczk]

Yes, Rust is a language with safe and unsafe features. So is Java and Python (and you admitted that in your comments). So Rust is not any less safe than Java or a Python but that logic, and the original point you’ve made in the first comment is incorrect.

Actually Rust is safer because its unsafe features must be surrounded by ‘unsafe’ keyword which is easy to look for, but you can’t say that about Java and Python.

[int_19h]

I can't think of anything in either Java or Python that is memory-unsafe when it comes to the languages themselves.

You can do unsafe stuff using stdlib in either language, sure. But by this standard, literally any language with FFI is "not any less safe" than C. Which is very technically correct, but it's not a particularly useful definition.