std::isnan

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Defined in header <cmath>

int isnan( float arg );
(C++11 feature)
int isnan( double arg );
(C++11 feature)
int isnan( long double arg );
(C++11 feature)

Determines if the given floating point number arg is not-a-number (NaN).

[edit] Parameters

arg - floating point value

[edit] Return value

nonzero value if arg is NaN, 0 otherwise

[edit] See also

fpclassify (C++11)
categorizes the given floating point value
(function)
isfinite (C++11)
checks if the given number has finite value
(function)
isinf (C++11)
checks if the given number is infinite
(function)
isnormal (C++11)
checks if the given number is normal
(function)