use std::any::TypeId;

trait IsSend {
    fn is_send(&self);
}

impl<T: Send + 'static> IsSend for T {
    fn is_send(&self){
        println!("TypeId of T: {:?}", TypeId::of::<T>());
    }
}

fn main() -> Result<(),Box<dyn std::error::Error>> {
    println!("TypeId of i32: {:?}", TypeId::of::<i32>());
    println!("TypeId of Rc<i32>: {:?}", TypeId::of::<std::rc::Rc<i32>>());

     let i = std::rc::Rc::new(43);
     i.is_send(); // (!!) no compiler error although Rc is not Send
     Ok(())
}