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use std::ops::{Deref, DerefMut};
use std::fmt::Debug;
use std::hash::Hash;

pub struct Takeable<T> {
    inner: Option<T>,
}

impl<T> Takeable<T> {
    #[inline]
    pub fn new(value: T) -> Takeable<T> {
        Takeable {inner: Some(value)}
    }

    #[inline]
    pub fn new_empty() -> Takeable<T> {
        Takeable {inner: None}
    }

    #[inline]
    pub fn take(slot: &mut Takeable<T>) -> T {
        slot.inner.take().unwrap()
    }
}

impl<T> Deref for Takeable<T> {
    type Target = T;
    #[inline]
    fn deref(&self) -> &Self::Target {
        self.inner.as_ref().unwrap()
    }
}

impl<T> DerefMut for Takeable<T> {
    #[inline]
    fn deref_mut(&mut self) -> &mut Self::Target {
        self.inner.as_mut().unwrap()
    }
}

impl<T: Debug> Debug for Takeable<T> {
    fn fmt(&self, fmt: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
        fmt.debug_tuple("Takeable").field(self.deref()).finish()
    }
}

impl<T: Clone> Clone for Takeable<T> {
    fn clone(&self) -> Self {
        Takeable::new(self.deref().clone())
    }

    fn clone_from(&mut self, source: &Self) {
        self.deref_mut().clone_from(source);
    }
}

impl<T: Default> Default for Takeable<T> {
    fn default() -> Self {
        Takeable::new(Default::default())
    }
}

impl<T: PartialEq> PartialEq for Takeable<T> {
    fn eq(&self, other: &Self) -> bool {
        self.deref().eq(other)
    }

    fn ne(&self, other: &Self) -> bool {
        self.deref().ne(other)
    }
}

impl<T: Eq> Eq for Takeable<T> {}

impl<T: PartialOrd> PartialOrd for Takeable<T> {
    fn partial_cmp(&self, other: &Self) -> Option<::std::cmp::Ordering> {
        self.deref().partial_cmp(other)
    }

    fn lt(&self, other: &Self) -> bool {
        self.deref().lt(other)
    }

    fn le(&self, other: &Self) -> bool {
        self.deref().le(other)
    }

    fn gt(&self, other: &Self) -> bool {
        self.deref().gt(other)
    }

    fn ge(&self, other: &Self) -> bool {
        self.deref().ge(other)
    }
}

impl<T: Ord> Ord for Takeable<T> {
    fn cmp(&self, other: &Self) -> ::std::cmp::Ordering {
        self.deref().cmp(other)
    }
}

impl<T: Hash> Hash for Takeable<T> {
    fn hash<H: ::std::hash::Hasher>(&self, state: &mut H) {
        self.deref().hash(state);
    }
}