2017-09-15

Aliases: HUGE_VAL(3), HUGE_VAL(3), HUGE_VAL(3), HUGE_VAL(3), HUGE_VAL(3), HUGE_VAL(3), HUGE_VAL(3), HUGE_VAL(3), HUGE_VALF(3), HUGE_VALF(3), HUGE_VALF(3), HUGE_VALF(3), HUGE_VALF(3), HUGE_VALF(3), HUGE_VALF(3), HUGE_VALF(3), HUGE_VALL(3), HUGE_VALL(3), HUGE_VALL(3), HUGE_VALL(3), HUGE_VALL(3), HUGE_VALL(3), HUGE_VALL(3), HUGE_VALL(3), NAN(3), NAN(3), NAN(3), NAN(3), NAN(3), NAN(3), NAN(3), NAN(3)

### manpages-dev

Manual pages about using GNU/Linux for development

### man-pages

Linux kernel and C library user-space interface documentation

## NAME

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

## SYNOPSIS

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

INFINITY

NAN

HUGE_VALHUGE_VALFHUGE_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.## CONFORMING TO

C99.

## AVAILABILITY

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.