Is this code well-defined?
- by Nawaz
This code is taken from a discussion going on here.
someInstance.Fun(++k).Gun(10).Sun(k).Tun();
Is this code well-defined? Is ++k Fun() evaluated before k in Sun()?
What if k is user-defined type, not built-in type? And in what ways the above function calls order is different from this:
eat(++k);drink(10);sleep(k);
As far as I can say, in both situations, there exists a sequence point after each function call. If so, then why can't the first case is also well-defined like the second one?
Section 1.9.17 of the C++ ISO standard says this about sequence points and function evaluation:
When calling a function (whether or
not the function is inline), there is
a sequence point after the evaluation
of all function arguments (if any)
which takes place before execution of
any expressions or statements in the
function body. There is also a
sequence point after the copying of a
returned value and before the
execution of any expressions outside
the function.
