#![allow(dead_code, deprecated, unused_variables, unused_mut)]
use std::any::Any;
fn print_if_string(s: &(dyn Any + Send + Sync)) {
    if let Some(string) = s.downcast_ref::<String>() {
        println!("It's a string({}): '{}'", string.len(), string);
    } else {
        println!("Not a string...");
    }
}
fn main() {
    print_if_string(&0);
    print_if_string(&"cookie monster".to_string());
}