> we care about the type of x because we need to cast to a 16-bit int because it is going to be use to communicate with hardware IMO you should still use auto

> we care about the type of x because we need to cast to a 16-bit int because it is going to be use to communicate with hardware IMO you should still use auto there and use a static_cast<int16_t> on the RHS to make it clear to the reader that you're deliberately converting it.