Macro impl_der 

macro_rules! impl_der {
    ($kind:ident $(($constructed:expr))?, borrowed, $fmt:ident, $inner:ty, $spec:ty, $value:ident $(, $forward:ty, $reverse:ty)?) => { ... };
    ($kind:ident $(($constructed:expr))?, owned, $fmt:ident, $inner:ty, $spec:ty, $value:ty $(, $forward:ty, $reverse:ty)?) => { ... };
    (@kind tagged($constructed:expr), $fmt:ident, $spec:ty $(, $forward:ty, $reverse:ty)?) => { ... };
    (@kind tagged_exact($constructed:expr), $fmt:ident, $spec:ty $(, $forward:ty, $reverse:ty)?) => { ... };
    (@kind tagged_identity($constructed:expr), $fmt:ident, $spec:ty $(, $forward:ty, $reverse:ty)?) => { ... };
    (@kind untagged_mask($domain:expr), $fmt:ident, $spec:ty $(, $forward:ty, $reverse:ty)?) => { ... };
    (@kind untagged_any, $fmt:ident, $spec:ty $(, $forward:ty, $reverse:ty)?) => { ... };
    (@kind untagged_start, $fmt:ident, $spec:ty $(, $forward:ty, $reverse:ty)?) => { ... };
    (@kind untagged, $fmt:ident, $spec:ty $(, $forward:ty, $reverse:ty)?) => { ... };
}

Implements the verified DER traits and executable APIs for a generated nominal format.