> So it would be enough to support the subset of Rust that gets actually used in the kernel. I would imagine they would be very conservative about which feature

> So it would be enough to support the subset of Rust that gets actually used in the kernel. I would imagine they would be very conservative about which features get used and adopt at a much slower speed. For now, it's the opposite: the kernel needs several Rust features which aren't even stable yet (https://github.com/Rust-for-Linux/linux/issues/2 https://github.com/Rust-for-Linux/linux/issues/2). But I agree that, after Rust has been in use in the kernel for a while (and it no longer needs any unstable features), the kernel developers are going to be somewhat conservative about which features are required (but not about which features are used; they probably will use a lot of conditional compilation, like they already do for gcc/clang, see the compiler-*.h files).