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#![no_std]

extern crate typenum;
extern crate void;

use typenum::*;
use void::Void;

mod private { pub trait Sealed {} }
impl private::Sealed for UTerm {}
impl<N: private::Sealed> private::Sealed for UInt<N, B0> {}
impl<N: private::Sealed> private::Sealed for UInt<N, B1> {}

pub trait FinBound: Unsigned + private::Sealed {
    type Fin;
}

impl FinBound for UTerm {
    type Fin = Void;
}

impl<N: FinBound> FinBound for UInt<N, B0> {
    type Fin = (bool, N::Fin);
}

impl<N: FinBound> FinBound for UInt<N, B1> {
    type Fin = Option<<UInt<N, B0> as FinBound>::Fin>;
}