closure_recursive.rs

fn test_closure_recursive() {
    struct Fact<'s> {
        f: &'s Fn(&Fact, u32) -> u32,
    }

    impl<'s> Fact<'s> {
        pub fn call(&self, i: u32) -> u32 {
            (self.f)(&self, i)
        }
    }

    let fact = Fact { f: &|fact, x| if x == 0 { 1 } else { x * (fact.f)(fact, x - 1) } };

    // println!("{}", (fact.f)(&fact, 5));
    println!("{}", fact.call(5));
}