Macro static_assertions::assert_eq_size_val

macro_rules! assert_eq_size_val {
    ($x:expr, $($xs:expr),+) => { ... };
}

Asserts at compile-time that the values have equal sizes.

Example

struct Byte(u8);

let x = 10u8;
let y = Byte(42); // Works for non-cloneable types

assert_eq_size_val!(x, y);
assert_eq_size_val!(x, y, 0u8);

// Fails to compile:
// assert_eq_size_val!(x, 0u32);