Macro impl_traits 

macro_rules! impl_traits {
    ($type:ty { $($trait_name:ident => $field:ident),* $(,)? }) => { ... };
    (@single $type:ty, Animatable, $_field:ident) => { ... };
    (@single $type:ty, Timed, $field:ident) => { ... };
    (@single $type:ty, Styled, $field:ident) => { ... };
}