trait Callable<A> {
    fn run(&mut self, input: A);
}

impl<A, T: Fn(A)> Callable<A> for T {
    fn run(&mut self, input: A) {
        self(input);
    }
}

fn say_hello(v: i32) {
    println!("hello {}", v)
}

fn process(mut service: impl Callable<i32>, a: i32) {
    service.run(a);
}

fn main() {
    process(say_hello, 33);
}