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  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.

RETURN VALUE

       See DESCRIPTION.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       ┌───────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │Interface                                                      │ Attribute     │ Value   │
       ├───────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │nextup(), nextupf(), nextupl(), nextdown(), nextdownf(),       │ Thread safety │ MT-Safe │
       │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)