[jerf]

Because "significantly more safe than C", while true, is also irrelevant. I want safe, not "safer than grotesquely unsafe". Unfortunately, for all the advances C++ has made, it is still in the "unsafe at any speed" class. It is difficult to escape the foundation of unsafety the entire C++ edifice rests on.

(At least, without further support. I consider "C/C++ with high quality static analysis" to be de facto distinct languages, and while I would favor something else even so, high-quality use of a high-quality static analyzer is enough to calm me down. Things have still crept through that level of care, but then, interpreters and compilers for safe languages have had safety errors in them before too.)

This is particularly true because it's just C and C++ that are memory unsafe. If we still in 1980, we could be arguing about the gradients of unsafety, but in 2023, we don't need to. Unsafety is not necessary at scale.

As for why people aren't asking to rewrite in Python, I partially answered that in my post. You can actually incrementally rewrite in Rust. You can't incrementally rewrite software in Python. There is also plenty of software that can be written in C, but simply can't be written in Python because it would be too slow. (Rewriting it in Python but oh no wait I'll just write the slow bits in C is a no-op, practically.)

As for trashing memory in Rust, by perfectly reasonable convention we generally understand that unsafe is unsafe, and that while languages can't avoid having it, having it does not necessarily make the entire rest of the language just as bad as C. I can crash Haskell with a straight-up, genuine null pointer exception with the Unsafe module in a single line of code. We do not thereby call Haskell an "unsafe" language where it is trivial to trash memory. Stock Rust is far safer than C++, to the point of being not only a qualitative change, but I'd contend, multiple such qualitative changes.

[jvanderbot]

Separating safe C/C++ from everyday C/C++ is not fair, in my opinion, but I get your point: If it can be abused it will be, either by accident, inexperience, or maliciousness.

Once you separate C/C++ into safe and unsafe cateogries, and admit that Rust has unsafe uses that are "just so much harder to use", we're clearly defining a gradient:

    C/C++, safer C/C++ subset or maybe Unsafe Rust, safer Rust, ...

[shikon7]

Sure you can use safe C++ with some effort, but the libraries you use most likely still use unsafe C/C++. For Rust, I expect that the libraries are much safer in general.