use default_boxed::DefaultBoxed; #[derive(DefaultBoxed)] struct Foo { b: ([u32; 1024 * 1024], [u32; 1024 * 1024]), } fn main() { let foo = Foo::default_boxed(); assert_eq!(foo.b.0[128 * 1024], 0); assert_eq!(foo.b.1[256 * 1024], 0); }