unique global id at compile time

unique.rs

#[derive(PartialEq, PartialOrd, Debug, Clone, Copy)]
pub struct UniqueId(pub u64);

macro_rules! unique {
    () => {{
        #[allow(missing_copy_implementations)]
        #[allow(non_camel_case_types)]
        #[allow(dead_code)]
        struct __unique_id_tag {};
        use core::any::TypeId;
        let tid = TypeId::of::<__unique_id_tag>();
        unsafe { $crate::debug::UniqueId(*((&tid as *const _) as *const u64)) }
    }};
}