INFINITY, NAN, HUGE_VAL, HUGE_VALF, HUGE_VALL - floating-point constants

#define _ISOC99_SOURCE /* See feature_test_macros(7) */
#include <math.h>

INFINITY

NAN

HUGE_VAL
HUGE_VALF
HUGE_VALL

The macro INFINITY expands to a float constant representing positive infinity.

The macro NAN expands to a float constant representing a quiet NaN (when supported). A quiet NaN is a NaN ("not-a-number") that does not raise exceptions when it is used in arithmetic. The opposite is a signaling NaN. See IEC 60559:1989.

The macros HUGE_VAL, HUGE_VALF, HUGE_VALL expand to constants of types double, float and long double, respectively, that represent a large positive value, possibly positive infinity.

fpclassify(3), math_error(7)