For builtin types, it really doesn't matter. But in C++, you can write
and operator++ for your own class. And then it might matter, becaure
postfix ++ has to create a copy of the object so that the old value can
be returned. If you don't need the return value, that copy is
unnecessary. If the compiler doesn't do named return value
optimization, that copy might even need to be copied again, and all
that just to throw the result away.