Is the behavior of return x++; defined?

Question

If I have for example a class with instance method and variables

class Foo
{

   ...

   int x;
   int bar() { return x++; }
 };

Is the behavior of returning a post-incremented variable defined?

Answer 1

Yes, it's equivalent to:

int bar()
{
  int temp = x;
  ++x;
  return temp;
}