std::isnormal
From cppreference.com
                    
                                        
                    
                    
                                                            
                    |   Defined in header  
<cmath>
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|   bool isnormal( float arg ); 
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(since C++11) | |
|   bool isnormal( double arg ); 
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(since C++11) | |
|   bool isnormal( long double arg ); 
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(since C++11) | |
Determines if the given floating point number arg is normal, i.e. is neither zero, subnormal, infinite, nor NaN.  
[edit] Parameters
| arg | - | floating point value | 
[edit] Return value
true if arg is normal, false otherwise
[edit] See also
|    (C++11) 
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   categorizes the given floating point value   (function)  | 
|    (C++11) 
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   checks if the given number has finite value   (function)  | 
|    (C++11) 
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   checks if the given number is infinite   (function)  | 
|    (C++11) 
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   checks if the given number is NaN  (function)  |