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playground.rs

#[cfg(test)]


mod tests {
use std::rc::Rc;
    // the `type` is not needed but it makes it easier if you will
    // be using it in other function declarations.
    type Adder = Fn(i32) -> i32;

    fn sum(x: Rc<i32>) -> Rc<Adder> {
        Rc::new(move |n: i32| *x + n)
    }

    #[test]
    fn it_works() {
        let foo = sum(Rc::new(2));
        assert_eq!(5, foo(3));
    }
}