use std::convert::TryFrom;

struct Numeric(u64);

enum SomeType {
    Numeric(Numeric),
}

macro_rules! impl_try_from {
    ($ty:ty) => {
        impl TryFrom<$ty> for SomeType {
            type Error = <u64 as TryFrom<$ty>>::Error;

            fn try_from(n: $ty) -> Result<Self, Self::Error> {
                u64::try_from(n).map(|n| SomeType::Numeric(Numeric(n)))
            }
        }
    };
}

impl_try_from!(u8);
impl_try_from!(u16);
impl_try_from!(u32);