#include <limits>
using namespace std;
const double double_nan = numeric_limits<double>::quiet_NaN();
double x = double_nan;
if (x == double_nan) cout << "OK" << endl;
I dont get OK! Why?
#include <limits>
using namespace std;
const double double_nan = numeric_limits<double>::quiet_NaN();
double x = double_nan;
if (x == double_nan) cout << "OK" << endl;
I dont get OK! Why?
#include <limits> using namespace std; const double double_nan = numeric_limits<double>::quiet_NaN(); double x = double_nan; if (x == double_nan) cout << "OK" << endl;
I dont get OK! Why?
Because a NAN wont compare to anything, even itself. You'd need to check the IEEE standard on floating point numbers for exactly why. (IEEE-754 I think). Simple as that.
Correct. NaN is defined mathematically to not be equal to itself.
Ok, thanks, this is a convention, its mathematically logical, but not lcical for a programer, because nan is also a bit series as any other number...
Are there any bool function which gives back true if a number is nan?
(ok I can write it, but are there any built in function?)
I found it pretty easy. Check this link.
Thanks a lot, Fbody....There goes my productivity for this morning...