Suppose we have this code (seen in an interview test), the order of arithmetical operations is well defined in the standard (left to right), but the question is: the order of execution for the functions is defined (the same as for the operations) or this code is undefined behavior?
int test_b = 1;
int test_x() {test_b++; return test_b;}
int test_y() {test_b = 3; return test_b - 1;}
int test_z() {test_b = test_b+8; return test_b + 2;}
int a = test_x() - test_y() + test_z();
Please keep in mind that this question is not related to sequence points (we have function calls)
PS: I have tried few online compilers on https://godbolt.org/, from what I have tested the result is always 13.