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/*!
Traits and types for comparison.
*/


/// Compares the ordering of Self and Right
pub trait Compare_<Right>{
    type Output;
}

/// Compares the ordering of Left and Right
pub type Compare<Left,Right>=
    <Left as Compare_<Right>>::Output;




/// A type-level equivalent of `Ordering::Less`
pub struct TLess;

/// A type-level equivalent of `Ordering::Equal`
pub struct TEqual;

/// A type-level equivalent of `Ordering::Greater`
pub struct TGreater;


////////////////////////////////////////////////////////////////////////////////

/// Reverses a type-level `Ordering`.
pub trait ReverseOrdering_{
    type Output;
}

/// Reverses a type-level `Ordering`.
pub type ReverseOrdering<This>=
    <This as ReverseOrdering_>::Output;


impl ReverseOrdering_ for TLess{
    type Output=TGreater;
}
impl ReverseOrdering_ for TEqual{
    type Output=TEqual;
}
impl ReverseOrdering_ for TGreater{
    type Output=TLess;
}


////////////////////////////////////////////////////////////////////////////////



#[cfg(test)]
mod tests{
    use super::*;
    use core_extensions::type_asserts::AssertEq;

    #[test]
    fn reverse(){
        let _:AssertEq<ReverseOrdering<TLess>,TGreater>;
        let _:AssertEq<ReverseOrdering<TEqual>,TEqual>;
        let _:AssertEq<ReverseOrdering<TGreater>,TLess>;
    }
}