use std::mem::offset_of; struct S { a: u8, b: (u8, u8), c: [i32], } struct T { x: i32, y: S, } type Tup = (i32, [i32]); fn main() { offset_of!(S, c); //~ ERROR size for values of type `[i32]` cannot be known at compilation time } fn other() { offset_of!(T, y); //~ ERROR size for values of type `[i32]` cannot be known at compilation time } fn tuple() { offset_of!(Tup, 1); //~ ERROR size for values of type `[i32]` cannot be known at compilation time }