You should only really use "auto" when the type is clear (like in your example #2). If it's not clear, you should probably specify the type so that it's more ob

You should only really use "auto" when the type is clear (like in your example #2). If it's not clear, you should probably specify the type so that it's more obvious what's going on. #1 and 3 are probably fine if x is defined right above y, but maybe not if they're at the bottom of a long function or similar.