isfinite
From cppreference.com
                    
                                        
                    
                    
                                                            
                    |   Defined in header <math.h>
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|   #define isfinite(arg) /* implementation defined */  | 
(since C99) | |
Determines if the given floating point number arg has finite value i.e. it is normal, subnormal or zero, but not infinite or NAN. The macro returns an integral value.
[edit] Parameters
| arg | - | floating point value | 
[edit] Return value
Nonzero integral value if arg has finite value, 0 otherwise.
[edit] See also
|    (C99)  | 
   categorizes the given floating point value   (function)  | 
|    (C99)  | 
   checks if the given number is infinite   (function)  | 
|    (C99)  | 
   checks if the given number is NaN  (function)  | 
|    (C99)  | 
   checks if the given number is normal   (function)  | 
|   C++ documentation for isfinite 
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