1 /*********************************************************************
2  *   Copyright 2018, University Corporation for Atmospheric Research
3  *   See netcdf/README file for copying and redistribution conditions.
4  *   Russ Rew
5  *********************************************************************/
6 #ifndef _ISNAN_H
7 #define _ISNAN_H
8 
9 #include "config.h"
10 
11 #ifndef NO_FLOAT_H
12 #include <float.h>		/* for DBL_MAX */
13 #endif /* NO_FLOAT_H */
14 #include <math.h>
15 
16 #if ! (defined(isinf) || HAVE_DECL_ISINF)
17 #define isinf(x) (DBL_MAX/((double)(x))==0.0)
18 #endif /* !HAVE_DECL_ISINF */
19 #if ! (defined(isnan) || HAVE_DECL_ISNAN)
20 #define isnan(x) ((x)!=(x))
21 #endif /* !HAVE_DECL_ISNAN */
22 #if ! (defined(isfinite) || HAVE_DECL_ISFINITE)
23 #define isfinite(x) (!(isinf(x)||isnan(x)))
24 #endif /* !HAVE_DECL_ISFINITE */
25 
26 #endif /* _ISNAN_H */
27