SF
I've just tried doing that, but it turns out to be basicaly a rust "wrapper" for C. I've got those results: 4776 B for no_std + C + no_main 257 KB for std + C + no_main 264 KB for std + no_main 282 KB for std All with opt-level=z I have also tried using just C, but that would require asembly to properly get rid of std, so the best I could achieve is 14KB with all the optimization I found and after stripping. Yep, very weird, writing C inside Rust is better, than writing pure C. Reminder of how smart Cargo/rustc are! Upd: 3680B with stripping Upd: Just realized I needed to staticly link it for it to be fair. Wellp, 12864B now.