小编Ola*_*ner的帖子

作为一个 Rust 新手，我可能有点天真地开始了这个：

...

pub trait Decode<T> {
    fn decode_from<R: io::Read + ?Sized>(&mut self, stream: &mut R) -> T;
}

pub struct MQTTFrame<'a> {
    pub payload: &'a Vec<u8>,
}

pub struct MQTTFrameDecoder<'a> {
    pub payload: &'a mut Vec<u8>,
}

impl<'a> Decode<MQTTFrame<'a>> for MQTTFrameDecoder<'a> {
    fn decode_from<R: io::Read + ?Sized>(&mut self, stream: &mut R) ->    MQTTFrame<'a> {
        stream.read(&mut self.payload);
        MQTTFrame{ payload: self.payload }
    }
}

其中，在尝试编译时，受到了欢迎：

src/testbed/mod.rs:31:24: 31:36 error: cannot infer an appropriate   lifetime for automatic coercion due to conflicting requirements …