Rust 我如何将特征作为 struct 的拥有字段

我对Rust还很陌生，我打算实现一个 struct ，该 struct 可以具有不同的 struct ，该 struct 将一个共同的特征实现为一个字段

在使用垃圾收集器的传统编程语言中，我会这样实现它:

pub struct MemoryMapper {
    regions: Vec<Region>,
}

trait MemoryMappable: Sized {
    
}

pub struct Region {
    device: dyn MemoryMappable,
    start: u32,
    end: u32,
    remap: bool
}

但在这里，我有以下编译错误:

the size for values of type `(dyn MemoryMappable + 'static)` cannot be known at compilation time
the trait `Sized` is not implemented for `(dyn MemoryMappable + 'static)`
only the last field of a struct may have a dynamically sized type
change the field's type to have a statically known size

我曾try 将Size设置为MemoyMappable的一个附加特征，但它仍然让我在以下代码中遇到问题:

pub fn map(&mut self, device: dyn MemoryMappable, start: u32, end: u32, remap: bool) -> &Region {
        self.regions.insert(0, Region{device, start, end, remap});
        return self.regions.get(0).unwrap();
}

the trait `MemoryMappable` cannot be made into an object
`MemoryMappable` cannot be made into an object

因为从Rust documentation about object safety

尺码不能是一种超级特征.换句话说，它不能要求自己的尺寸.

在这一点上我不知道该怎么做.