add maybe_write() for lazy data closures on Endpoint and UsbBus #78
  Add this suggestion to a batch that can be applied as a single commit.
  This suggestion is invalid because no changes were made to the code.
  Suggestions cannot be applied while the pull request is closed.
  Suggestions cannot be applied while viewing a subset of changes.
  Only one suggestion per line can be applied in a batch.
  Add this suggestion to a batch that can be applied as a single commit.
  Applying suggestions on deleted lines is not supported.
  You must change the existing code in this line in order to create a valid suggestion.
  Outdated suggestions cannot be applied.
  This suggestion has been applied or marked resolved.
  Suggestions cannot be applied from pending reviews.
  Suggestions cannot be applied on multi-line comments.
  Suggestions cannot be applied while the pull request is queued to merge.
  Suggestion cannot be applied right now. Please check back later.
  
    
  
    
The
write()API forEndpointis a little clumsy because it returns an error if the write would block, forcing the code that invokes it to hang on to the buffer and retry later.This is a solution, but it adds method to the
UsbBustrait, forcing downstream implementers to update (see twitchyliquid64/usbd-hid#34 ).I am mostly trying to start a conversation about this so options (such as the ability to check
WouldBlockbefore callingwrite) can be discussed.