[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.

[pkolaczk]

Standard library is an inherent part of the language. There is no difference for the end user, whether the call to `unsafe` is a language builtin or a standard library call. The end result is, all of those languages have large safe subsets and you can opt-in into unsafety to do advanced stuff. And there isn't anything in the safe subset of Java / Python that you would need to use unsafe for when translating it to Rust.

[int_19h]

Again, by this standard, literally any language with FFI is "unsafe". This is not a useful definition in practice.

As far as translation of Java or Python to safe Rust, sure, if you avoid borrow checking through the usual tricks (using indices instead of pointers etc), you can certainly do so in safe Rust. In the same vein, you can translate any portable C code, no matter how unsafe, to Java or Python by mapping memory to a single large array and pointers to indices into that array (see also: wasm). But I don't think many people would accept this as a reasonable argument that Java and C are the same when it comes to memory safety.

[pkolaczk]

So you can see that the fact you can invoke unsafe code is not a good distinguishing factor. It is the other, safe part. Rust, Java and Python all have huge memory safe subsets that are practical for general purpose programming - almost all of the features are available in those safe subsets. C and C++ do not - in order to make them memory safe you’d have to disallow most of the useful features eg everything related to pointers/references and dynamic memory.