**nextafter**

- floating-point number manipulation
SYNOPSIS
#include <math.h>
double nextafter(double x, double y);
float nextafterf(float x, float y);
long double nextafterl(long double x, long double y);
double nexttoward(double x, long double y);
float nexttowardf(float x, long double y);
long double nexttowardl(long double x, long double y);
Link with -lm.
Feature Test Macro Requirements for glibc (see **feature_test_macros(7)**):
nextafter():
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 ||
_XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
or cc -std=c99
nextafterf(), nextafterl():
_BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 600 ||
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;
or cc -std=c99
nexttoward(), nexttowardf(), nexttowardl():
_XOPEN_SOURCE >= 600 || _ISOC99_SOURCE ||
_POSIX_C_SOURCE >= 200112L;
or cc -std=c99
DESCRIPTION
The nextafter() functions return the next representable floating-point
value following x in the direction of y. If y is less than x, these
functions will return the largest representable number less than x.
If x equals y, the functions return y.
The nexttoward() functions do the same as the nextafter() functions,
except that they have a long double second argument.
RETURN VALUE
On success, these functions return the next representable floating-
point value after x in the direction of y.
If x equals y, then y (cast to the same type as x) is returned.
If x or y is a NaN, a NaN is returned.
If x is finite, and the result would overflow, a range error occurs,
and the functions return HUGE_VAL, HUGE_VALF, or HUGE_VALL, respec-
tively, with the correct mathematical sign.
If x is not equal to y, and the correct function result would be sub-
Range error: result is subnormal or underflows
An underflow floating-point exception (FE_UNDERFLOW) is raised.
These functions do not set errno.
CONFORMING TO
C99, POSIX.1-2001. This function is defined in IEC 559 (and the appen-
dix with recommended functions in IEEE 754/IEEE 854).
BUGS
In glibc version 2.5 and earlier, these functions do not raise an
underflow floating-point (FE_UNDERFLOW) exception when an underflow
occurs.
SEE ALSO
**nearbyint(3)**
COLOPHON
This page is part of release 3.35 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can
be found at http://man7.org/linux/man-pages/.
GNU 2010-09-20 **NEXTAFTER(3)**

###### Man Pages Copyright Respective Owners. Site Copyright (C) 1994 - 2017
Hurricane Electric.
All Rights Reserved.