[WorldMaker]

Hah, just this sort of confusion is part of the proposal to drop ++ and -- from Swift.

x++ returns x and then increments it, so yes the spec agrees with your intuition here.

Whereas ++x increments x and then returns the incremented x.

That subtle difference between x++ and ++x has been the debugging nightmare of many a C developer over the years. It's also why there's a fun irony in the C++ name and why people say the actual successor to C will be ++C.

[marcosdumay]

What?

I was talking about my statement at the upper comment. I used x++ there, not ++x. The doubt is about the value of the other x.

The difference you talk is about the main behavior of the operators. You won't find any description of them that does not state it.

[WorldMaker]

Well, I made the wrong assumption in what was being asked then, I guess. I would presume the "left to right" rule is more generally assumed knowledge in C/C++ than postfix/prefix distinction of ++/-- which are pretty much the only unary operators with such a distinction in the language, whereas "left to right" is a rather underlying general rule and one in which you generally assume people are familiar with.

My apologies for answering the wrong question, but yes in that case the standard is also mostly clear that you can assume that things are evaluated from left to right in C/C++ and thus the first x in the line should be evaluated prior to the x++ later in the line...