use default_boxed::DefaultBoxed; #[derive(DefaultBoxed)] struct Foo([u32; 4 * 1024 * 1024], [u16; 4 * 1024 * 1024]); fn main() { let foo = Foo::default_boxed(); assert_eq!(foo.0[1024], 0); assert_eq!(foo.1[2048], 0); }