One big issue with D compared to Rust for performance-oriented code is the lack of move semantics. Rust and C++ idiomatically almost never rely on copy-on-write

One big issue with D compared to Rust for performance-oriented code is the lack of move semantics. Rust and C++ idiomatically almost never rely on copy-on-write, whereas D so far has a lot of it. I'm not sure how much this matters for kernel modules, but I imagine that it is something users would consider. I had seen some proposals for move semantics in D, so for all I know this is under works right now.