INFINITY(3) | Library Functions Manual | INFINITY(3) |
NAME¶
INFINITY, NAN, HUGE_VAL, HUGE_VALF, HUGE_VALL - floating-point constants
LIBRARY¶
Math library (libm)
SYNOPSIS¶
#define _ISOC99_SOURCE /* See feature_test_macros(7) */ #include <math.h>
INFINITY
NAN
HUGE_VAL HUGE_VALF HUGE_VALL
DESCRIPTION¶
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.
STANDARDS¶
C11.
HISTORY¶
C99.
On a glibc system, the macro HUGE_VAL is always available. Availability of the NAN macro can be tested using #ifdef NAN, and similarly for INFINITY, HUGE_VALF, HUGE_VALL. They will be defined by <math.h> if _ISOC99_SOURCE or _GNU_SOURCE is defined, or __STDC_VERSION__ is defined and has a value not less than 199901L.
SEE ALSO¶
2023-03-30 | Linux man-pages 6.04 |