#![allow(dead_code, deprecated, unused_variables, unused_mut)] use std::mem; #[repr(C)] struct FieldStruct { first: u8, second: u16, third: u8, } #[repr(C)] struct NestedA { b: NestedB, } #[repr(C)] struct NestedB(u8); fn main() { assert_eq!(mem::offset_of!(FieldStruct, first), 0); assert_eq!(mem::offset_of!(FieldStruct, second), 2); assert_eq!(mem::offset_of!(FieldStruct, third), 4); assert_eq!(mem::offset_of!(NestedA, b.0), 0); }