rust怎么实现 trait object向其实现类型的转换？

[kkkkkkkkkkkkikkkkk]

就像大多数面向对象语言的父类转子类， 接口转实现一样

interface Greet {
  public void say();
}

class Student implements Greet {
  public String name;
  public void say() {
    System.out.println("student");
  }
}

class Teacher implements Greet {
  public String classz;
  public void say() {
    System.out.println("teacher");
  }
}

List<Greet> dp = new ArrayList();
    dp.add(new Student());
    dp.add(new Teacher());

    Teacher d = (Teacher)dp.get(1);

接口类型可以强转为实现类。

在rust里怎么实现这种功能？
请教请教

[kkkkkkkkkkkkikkkkk]

没人没人回啊

[skyf**er]

let tests = vec![
        Tests::new("x"),
        Tests::new("y"),
        Tests::new("foobar"),
    ];
    
    
    for (i,v)  in tests.iter().enumerate() {
        let tmp:& Box<dyn ast::Node> = &program.statements[i];
        
        let b: &ast::LetStatement = match tmp.as_any().downcast_ref::<ast::LetStatement>() {//类似接口断言...
            Some(b) =>b,
            None =>panic!("&Node is not a let statement"),
        };
        
        test_let_statment_helper(b,&v.expectedIdentifier);
    }

    //结构体定义
    use std::any::Any;
    pub trait Node: std::fmt::Debug {
        fn token_literal(&self) -> String;
        fn as_any(&self) -> &dyn Any;
    }
    
    impl  Node for Program {
    fn token_literal(&self) ->String {
        if self.statements.len()>0 {
            return self.statements[0].token_literal();
        }
        "".to_string()
    }
    fn as_any(&self)->&dyn Any{
        self
    }
}