Impl Read<u8> / Write<u8> for Serial

[dbrgn]

Is there a reason why Read / Write is only implemented for Rx and Tx (obtainable via split()) but not on the Serial type directly?

Other HALs like the stm32f4xx-hal have such impls.

I'm working with a driver that wants a Read<u8> + Write<u8> type and I don't want to create a wrapper type with my own impl if not necessary 🙂

[TheZoq2]

I don't believe there is an underlying reason, it's just that nobody has gotten around do doing it yet :)

[dbrgn]

Hm, I tried to implement it, but I realized that for this struct:

pub struct Serial<USART, PINS> {
    usart: USART,
    pins: PINS,
}

...the Read / Write traits cannot be implemented, as it is not known how to get to the pin types from the generic PINS type argument.

One workaround would be to implement Read / Write for a tuple (Tx, Rx), but that's a bit of a hack in my opinion.

The better solution in my eyes would be to replace the Pins trait with separate TxPin / RxPin traits, as I did in the stm32l0xx-hal. Any opinions on that? It would be a breaking change, but we're still on version 0.x so I guess that's fine 🙂

[TheZoq2]

Any opinions on that? It would be a breaking change, but we're still on version 0.x so I guess that's fine slightly_smiling_face

Sounds like a good idea. We have breaking changes all the time 😉