std::isinf

From Cppreference

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Defined in header <cmath>
int isinf( float arg );		(C++11 feature)
int isinf( double arg );		(C++11 feature)
int isinf( long double arg );		(C++11 feature)

Determines if the given floating point number arg is positive or negative infinity.

[edit] Parameters

arg

-

floating point value

[edit] Return value

nonzero value if arg is infinite, ​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)
isnan (C++11)	checks if the given number is NaN (function)
isnormal (C++11)	checks if the given number is normal (function)