rust--如何打印struct实例对象?

fn example1() {
     // 第一种方法是给Struct增加一个derive(Debug).
     #[derive(Debug)]
     struct MyStruct {x: i32, y: i32}
     let ms = MyStruct {x: 0, y: 10};
     println!("{:?}", ms)
}


fn example2() {
     // 第二种方法是自己去实现一个Display.
     // Refer: https://stackoverflow.com/questions/30253422/how-to-print-structs-and-arrays
     struct MyStruct {a: i32, b: i32}

     impl std::fmt::Display for MyStruct {
         fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
             write!(f, "(value a: {}, value b: {})", self.a, self.b)
         }
     }

     let ms = MyStruct { a: 0, b: 15 };
     println!("Used Display: {}", ms);
}


fn main() {
     example1();                // output: MyStruct { x: 0, y: 10 }
     example2();       // output: Used Display: (value a: 0, value b: 15)
}