nextup, nextupf, nextupl, nextdown, nextdownf, nextdownl - return next
floating-point number toward positive/negative infinity
#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);
Link with
-lm.
The
nextup(),
nextupf(), and
nextupl() functions return the
next representable 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.
See DESCRIPTION.
These functions first appeared in glibc in version 2.24.
For an explanation of the terms used in this section, see
attributes(7).
| Interface |
Attribute |
Value |
| nextup (), nextupf (), nextupl (), nextdown (), nextdownf (), nextdownl
() |
Thread safety |
MT-Safe |
These functions are described in
IEEE Std 754-2008 - Standard for
Floating-Point Arithmetic and
ISO/IEC TS 18661.
nearbyint(3),
nextafter(3)