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use crate::property::Region;

pub trait Sorted: Iterator {}

pub trait AssumeSorted: Iterator + Sized {
    fn assume_sorted(self) -> AssumingSortedIter<Self>
    where
        Self::Item: Region,
    {
        AssumingSortedIter { inner: self }
    }
}

impl<T: Iterator> AssumeSorted for T {}

pub struct AssumingSortedIter<T: Iterator> {
    inner: T,
}

impl<T: Iterator> Iterator for AssumingSortedIter<T> {
    type Item = T::Item;
    fn next(&mut self) -> Option<Self::Item> {
        self.inner.next()
    }
}

impl<T: Iterator> Sorted for AssumingSortedIter<T> {}

impl<T: Iterator + Sorted, P> Sorted for std::iter::Filter<T, P> where P: Fn(&T::Item) -> bool {}