#![feature(core_intrinsics)]
use std::collections::HashMap;

fn main() {
    let mut hm = HashMap::new();
    hm.insert(1, 2);

    let mut xx = hm.get_mut(&1);

    // xx = 3;
    // println!("{:?}",xx);
    print_type_name_of(xx);
}

fn print_type_name_of<T>(_: T) {
    println!("{}", unsafe { std::intrinsics::type_name::<T>() })
}