Rust 无法将记录器向下转换回原始 struct

我想访问我的log::Log个Impl实例以访问特定的字段，但一旦我收到引用，我就不能将其向下转换到我的 struct 中.

我试图将记录器引用转换为core::any::Any，然后将其向下转换为我的原始 struct ，但我总是得到None.

use core::any::Any;

pub trait AToAny: 'static {
    fn as_any(&self) -> &dyn Any;
}

impl<T: 'static> AToAny for T {
    fn as_any(&self) -> &dyn Any {
        self
    }
}

struct MyLogger {}

impl log::Log for MyLogger {
    fn enabled(&self, _: &log::Metadata<'_>) -> bool { todo!() }
    fn log(&self, _: &log::Record<'_>) { todo!() }
    fn flush(&self) { todo!() }
}

pub fn main() {
    let logger_impl = MyLogger {};
    log::set_boxed_logger(Box::new(logger_impl)).unwrap();
    let logger = log::logger();
    
    let logger_any = logger.as_any();
    let logger_impl = logger_any.downcast_ref::<MyLogger>()
        .expect("downcast failed");
}

我也try 了，但没有通过日志(log)初始化函数，但我得到了相同的结果:

use core::any::Any; // 0.10.1

pub trait AToAny: 'static {
    fn as_any(&self) -> &dyn Any;
}

impl<T: 'static> AToAny for T {
    fn as_any(&self) -> &dyn Any {
        self
    }
}

struct MyLogger {}

impl log::Log for MyLogger {
    fn enabled(&self, _: &log::Metadata<'_>) -> bool { todo!() }
    fn log(&self, _: &log::Record<'_>) { todo!() }
    fn flush(&self) { todo!() }
}

pub fn main() {
    let logger_impl = MyLogger {};
    let logger_boxed: Box<MyLogger> = Box::new(logger_impl);
    let logger: &'static mut dyn log::Log = Box::leak(logger_boxed);
    
    let logger_any = logger.as_any();
    let logger_impl = logger_any.downcast_ref::<MyLogger>()
        .expect("downcast failed");
}

这是code on the playground美元.

我看到logger变量中的type_id与logger_impl中的type_id不同，所以我相信这就是阻止我进行向下预测的原因，但我不能理解我应该如何修复这个问题.