#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.
These functions first appeared in glibc in version 2.24.
For an explanation of the terms used in this section, see attributes(7).
|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.
This page is part of release 5.13 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.
The man pages nextdown(3), nextdownf(3), nextdownl(3), nextupf(3) and nextupl(3) are aliases of nextup(3).