use std::collections::HashMap;

struct MyStruct {
    my_vec: HashMap<i32, Box<MyCallback>>,
    val: String,
}

struct MyCallback;

impl MyCallback {
    fn call(&self, my_struct: &MyStruct) {
        println!("{:?}", &my_struct.val);
    }
}

impl MyStruct {
    fn new() -> Self {
        let mut my_vec = HashMap::new();
        let my_callback = Box::new(MyCallback {});
        let my_callback2 = Box::new(MyCallback {});
        my_vec.insert(1i32, my_callback);
        my_vec.insert(2i32, my_callback2);
        Self {
            my_vec,
            val: "hello".to_string(),
        }
    }
}

fn main() {
    let my_struct = MyStruct::new();
    let vectorr = &my_struct.my_vec;

    let xx = vectorr.get(&1).unwrap();

    xx.call(&my_struct);
}