nextup(3) Library Functions Manual nextup(3)
NAME
nextup, nextupf, nextupl, nextdown, nextdownf, nextdownl - return next
floating-point number toward positive/negative infinity
LIBRARY
Math library (libm, -lm)
SYNOPSIS
#define _GNU_SOURCE /* See feature_test_macros(7) */
#include <math.h>
double nextup(double x);
float nextupf(float x);
long double nextupl(long double x);
double nextdown(double x);
float nextdownf(float x);
long double nextdownl(long double x);
DESCRIPTION
The nextup(), nextupf(), and nextupl() functions return the next repre-
sentable floating-point number greater than x.
If x is the smallest representable negative number in the corresponding
type, these functions return -0. If x is 0, the returned value is the
smallest representable positive number of the corresponding type.
If x is positive infinity, the returned value is positive infinity. If
x is negative infinity, the returned value is the largest representable
finite negative number of the corresponding type.
If x is Nan, the returned value is NaN.
The value returned by nextdown(x) is -nextup(-x), and similarly for the
other types.
RETURN VALUE
See DESCRIPTION.
ATTRIBUTES
For an explanation of the terms used in this section, see attrib-
utes(7).
┌───────────────────────────────────────────┬───────────────┬─────────┐
│ Interface │ Attribute │ Value │
├───────────────────────────────────────────┼───────────────┼─────────┤
│ nextup(), nextupf(), nextupl(), │ Thread safety │ MT-Safe │
│ nextdown(), nextdownf(), nextdownl() │ │ │
└───────────────────────────────────────────┴───────────────┴─────────┘
STANDARDS
These functions are described in IEEE Std 754-2008 - Standard for
Floating-Point Arithmetic and ISO/IEC TS 18661.
HISTORY
glibc 2.24.
SEE ALSO
nearbyint(3), nextafter(3)
Linux man-pages 6.7 2023-10-31 nextup(3)
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