I am trying to implementation a function isnan() which returns true if the number is not-a-number else will return false.
That's simple enough; define a reserved value to represent nan
(as you have for the infinities), and compare with that:
bool isnan(fixed_point x) {
return x == fixed_point::nan();
}
I want to do somewhat like the code shown below if positive and negative infinity values are added, the isnan function should return 1 else 0
It would be the responsibility of the addition operator to check the inputs and return nan
if appropriate:
fixed_point operator+(fixed_point x, fixed_point y) {
if (x == fixed_point::nan() || y == fixed_point::nan()) {
return nan;
}
if (x == fixed_point::positive_infinity()) {
return y == fixed_point::negative_infinity() ? fixed_point::nan() : x;
}
// and so on
}
then the test in main
becomes:
bool nan = fixed_point::isnan(a+b);