Rust: kernel vs user-space

I hesitate to step into this discussion but is it worth making the distinction between
Rust in the kernel and Rust in user-space?

I can see the argument for introducing a "safer" language into the kernel and there are
very few candidates available: perhaps only Rust, C++ and Zig. Clearly if that step is to
be made, it probably should pick one language and run with it.

That's one discussion.

As for user-space, I find the rationale for Rust as the one-true-language-after-C far less
compelling as many CLIs and server programs can just as well be written in more accessible
languages such as go or perl or java or...

Frankly I no longer write any CLI or server code in C even after decades of doing so
because the trade-off between development costs and performance is far less compelling in
user-space. If my once-a-week invocation of a command requires a bit more memory and CPU
than one written in C, is that really important compared to how much easier the command is
to maintain and enhance?

Point being, on the matter of introducing Rust to FreeBSD, I think the distinction between
kernel and user-space is worth keeping in mind as they are quite different problems.


Mark.