The compiler can evaluate the function printcbase()
as this:
void printcbase(cbase* b ){
int a = b->FooA(); // line 1
int b = b->FooB(); // line 2
std::cout << a; // line 3
std::cout << b; // line 4
stc::cout << std::endl;
}
or some of many permutatins of lines marked as 1 - 4. You are only guaranteed that that the line 1 is done before the line 3, and line 2 before the line 4 (and of course line 3 before line 4). Standard does not say more and indeed you can expect different results with different C++ compilers.