Timer trait error mismatch

[ryankurte]

In the timer trait, the CountDown and Cancel traits share an error definition, but try_wait and try_cancel return different types, which is not ideal for implementation. Discovered in stm32-rs/stm32f4xx-hal#172. I'm not sure of the correct change but, any change would be breaking so a decision on this blocks #177.

cc. @therealprof

[eldruin]

Maybe the problem in stm32-rs/stm32f4xx-hal#172 could be solved with a different Error type in CountDown. I left a comment about it here.

We could also discuss whether a common Error type makes sense for these two traits. Separate Error types are possible at the expense of fully-qualified syntax.

[ryankurte]

Maybe the problem in stm32-rs/stm32f4xx-hal#172 could be solved with a different Error type in CountDown. I left a comment about it here.

Yeah you got it, thanks!

We could also discuss whether a common Error type makes sense for these two traits.

Given my complaint wasn't valid, and sharing error types there seems fine, unless you have a strong opinion I would rather not add this to the list of things to worry about at this time.

[eldruin]

Great. Glad to help.