use std::collections::HashMap;
use std::rc::Rc;
use std::any::Any;

trait Attribute: AsAny {
    fn memory_size(&self) -> u32 { 42 }
}

impl Attribute for (f32, f32) {}
impl Attribute for u32 {}

fn main() {
    let mut h = HashMap::<String, Rc<dyn Attribute>>::new();

    h.insert("foo".into(), Rc::new((22.0, 22.0)));
    h.insert("bar".into(), Rc::new(42));

    let size = h.values()
        .map(|rc| rc.memory_size())
        .sum::<u32>();

    if let Ok(attr) = h.get_mut("foo").unwrap()
        .clone().into_any_rc()
        .downcast::<(f32, f32)>()
    {
        dbg!(attr);
    }
}


trait AsAny {
    fn into_any_rc(self: Rc<Self>) -> Rc<dyn Any>;
}

impl<T: Any> AsAny for T {
    fn into_any_rc(self: Rc<Self>) -> Rc<dyn Any> {
        self
    }
}