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    // Extracted from the scopeguard crate
    use core::{
        mem,
        ops::{Deref, DerefMut},
        ptr,
    };

    pub struct ScopeGuard<T, F>
    where
        F: FnMut(&mut T),
    {
        dropfn: F,
        value: T,
    }

    #[inline]
    pub fn guard<T, F>(value: T, dropfn: F) -> ScopeGuard<T, F>
    where
        F: FnMut(&mut T),
    {
        ScopeGuard { dropfn, value }
    }

    impl<T, F> ScopeGuard<T, F>
    where
        F: FnMut(&mut T),
    {
        #[inline]
        pub fn into_inner(guard: Self) -> T {
            // Cannot move out of Drop-implementing types, so
            // ptr::read the value and forget the guard.
            unsafe {
                let value = ptr::read(&guard.value);
                // read the closure so that it is dropped, and assign it to a local
                // variable to ensure that it is only dropped after the guard has
                // been forgotten. (In case the Drop impl of the closure, or that
                // of any consumed captured variable, panics).
                let _dropfn = ptr::read(&guard.dropfn);
                mem::forget(guard);
                value
            }
        }
    }

    impl<T, F> Deref for ScopeGuard<T, F>
    where
        F: FnMut(&mut T),
    {
        type Target = T;
        #[inline]
        fn deref(&self) -> &T {
            &self.value
        }
    }

    impl<T, F> DerefMut for ScopeGuard<T, F>
    where
        F: FnMut(&mut T),
    {
        #[inline]
        fn deref_mut(&mut self) -> &mut T {
            &mut self.value
        }
    }

    impl<T, F> Drop for ScopeGuard<T, F>
    where
        F: FnMut(&mut T),
    {
        #[inline]
        fn drop(&mut self) {
            (self.dropfn)(&mut self.value);
        }
    }