# Error code E0566

Conflicting representation hints have been used on a same item.

Erroneous code example:

    #![allow(unused)]
    fn main() {
    #[repr(u32, u64)]
    enum Repr { A }
    }

In most cases (if not all), using just one representation hint is more than enough. If you want to have a representation hint depending on the current architecture, use `cfg_attr`. Example:

    #![allow(unused)]
    fn main() {
    #[cfg_attr(linux, repr(u32))]
    #[cfg_attr(not(linux), repr(u64))]
    enum Repr { A }
    }