How to return NaN in C++

Since C++11 returning NaN as double is as simple as

return_nan_double.cpp

#include <cmath>

return std::nan("");

#include <cmath>

return std::nan("");

In case you want to return a float use

return_nan_float.cpp

#include <cmath>

return std::nanf("");

#include <cmath>

return std::nanf("");

In the rare case of a long double use

return_nan_longdouble.cpp

#include <cmath>

return std::nan("");

#include <cmath>

return std::nan("");

Check out similar posts by category: C/C++

If this post helped you, please consider buying me a coffee or donating via PayPal to support research & publishing of new posts on TechOverflow