delegare

优点

• 比 auto_delegatecrate 更快
• 比 deleagatecrate 更容易

缺点

• 所有可委托的特质都必须是 对象安全的。

此crate的示例

#[delegate]
pub trait Read {
    fn read(&self) -> &usize;
}

#[derive(Delegate)]
struct Wrapper<R>
where
    R: Read,
{
    #[to(Read)]
    inner: R,
}

struct Io {
    value: usize,
}

impl Read for Io {
    fn read(&self) -> &usize {
        &self.value
    }
}

fn main() {
    let wrapper = Wrapper {
        inner: Io { value: 1 },
    };
    wrapper.read();
}