CustomSmartPointer.rs

use std::ops::Deref;
struct CustomSmartPointer {
    data: String,
}

impl Deref for CustomSmartPointer {
    type Target = String;
    fn deref(&self) -> &Self::Target {
        &self.data
    }
}

impl Drop for CustomSmartPointer {
    fn drop(&mut self) {
        println!("Dropping CustomSmartPointer with data {}", self.data)
    }
}

fn add_bar(s: &str) -> String {
    let mut ans = String::from(s);
    ans.push_str("Bar");
    ans
}

fn main() {
    let c = CustomSmartPointer {
        data: String::from("Jiayi"),
    };
    // Deref coersion happens for function calls
    add_bar(&c);
    // However, deref coersion DON"T happen for macro calls
    println!("Finishing main function! {}", &c);
}