gistfile1.txt

use std::rc::Rc;
use std::cell;
use std::ops::{Deref, DerefMut};

pub struct SCell<T>(Rc<cell::RefCell<T>>);

pub struct Ref<'a, T: 'a>(cell::Ref<'a, T>);
pub struct RefMut<'a, T: 'a>(cell::RefMut<'a, T>);

impl<T> SCell<T> {
    fn borrow(&self) -> Ref<T> {
        Ref(self.0.borrow())
    }

    fn borrow_mut(&self) -> RefMut<T> {
        RefMut(self.0.borrow_mut())
    }
}

impl<'a, T: ?Sized + 'a> Deref for Ref<'a, T> {
    type Target = T;

    fn deref(&self) -> &T {
        &*self.0
    }
}

impl<'a, T> Deref for RefMut<'a, T>
    where T: 'a
{
    type Target = T;

    fn deref(&self) -> &T {
        &*self.0
    }
}

impl<'a, T> DerefMut for RefMut<'a, T>
    where T: 'a
{
    fn deref_mut(&mut self) -> &mut T {
        &mut *self.0
    }
}