131. mem::offset_of! — Byte Offsets Without the memoffset Crate

Sun, 10 May 2026 17:00:00 +0100

You need the byte offset of a field — for FFI, custom serialization, or talking to a C struct. The old answer was unsafe pointer arithmetic on a MaybeUninit, or pulling in the memoffset crate. std::mem::offset_of! is the safe, one-liner replacement.

Ffi on rustbites

131. mem::offset_of! — Byte Offsets Without the memoffset Crate