std::isfinite

From Cppreference

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

Determines if the given floating point number arg has finite value i.e. it is normal, subnormal or zero, but not infinite or NAN.

[edit] Parameters

arg

-

floating point value

[edit] Return value

nonzero value if arg has finite value, ​0​ otherwise

[edit] See also

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