SPI was invented before there was proper exception handling, so it
communicates errors by return values. This makes programming with SPI
either prone to errors of omission, or very ugly (ultimately, the
standard reasons why exceptions were invented).
So I was pondering whether we could introduce exceptions to SPI in some
way. I'm not sure how. We could invent an entirely separate set of
functions, or do some tricks in the header that things before
differently depending on some #define. Any ideas?
