Post #148 304 Sep 4, 2016, 19:18 UTC http://stackoverflow.com/questions/570669/checking-if-a-double-or-float-is-nan-in-cTags: #programming Stack Overflow Checking if a double (or float) is NaN in C++ Is there an isnan() function? PS.: I'm in MinGW (if that makes a difference). I had this solved by using isnan() from <math.h>, which doesn't exist in <cmath>, which I was #includeing...