Re: The Case for Rust (in the base system)

On 23 Jan 2024, at 14:55, Robert R. Russell <robert@rrbrussell.com> wrote:
> 
> The specific anti-patterns is was thinking of in both instances is
> called Meta Template Programming. Back in C++03 I just used the
> template system as a form of generics. In that role it works well and
> with the new smart pointers definitely improves some of the older
> problems C++ had.

Template metaprogramming is a core feature of C++, and more recent versions have added constexpr / consteval / constinit and concepts to make it a lot more readable.  It can be abused, but it is not, in itself, bad.  My example from earlier in the thread used template metaprogramming to do compile-time checks of correctness of the overflow / wrapping behaviour of a ring buffer.  Making it easy to check properties of your code at compile time is very much a feature, not an antipattern and it’s hard to see how you could argue the converse without arguing that bugs are a good idea.

> However, C++ definitely has a complexity cult and a ricer cult in its
> community. The overlap between the two appears to be fairly large which
> worries me.

Non-specific ad-hominem arguments are tremendously unhelpful.

> I have less reservations about C++ than I did earlier, though I think
> the build system may require major surgery to support it well.

The build system for both userspace and the kernel already support C++.  I have written a kernel module in C++ in the past.  Currently, there’s no mechanism in the kernel loader to support COMDATs (and I don’t really want to add it, I’d much rather handle them as an install-time preprocessing step for kernel modules), so you can’t load kernel modules that use inline functions / variables, but that’s orthogonal to the build system.

David