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std::isunordered

Defined in header <cmath> 
bool isunordered( float x, float y );
 (1) (since C++11) 
bool isunordered( double x, double y );
 (2) (since C++11) 
bool isunordered( long double x, long double y );
 (3) (since C++11) 
bool isunordered( Arithmetic x, Arithmetic y );
 (4) (since C++11)
1-3) Determines if the floating point numbers x and y are unordered, that is, one or both are NaN and thus cannot be meaningfully compared with each other.
4) A set of overloads or a function template for all combinations of arguments of arithmetic type not covered by (1-3). If any argument has integral type, it is cast to double.

Parameters

x - floating point value
y - floating point value

Return value

true if either x or y is NaN, false otherwise.

See also

(C++11)
 categorizes the given floating point value
(function)
(C++11)
 checks if the given number is NaN
(function)

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