Updated: 2022/Sep/29

```NEXTAFTER(3)               Library Functions Manual               NEXTAFTER(3)

NAME
nextafter, nextafterf, nextafterl, nexttoward, nexttowardf, nexttowardl -
next representable floating-point number

LIBRARY
Math Library (libm, -lm)

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);

DESCRIPTION
The nextafter(), nextafterf(), and nextafterl() functions return the next
machine representable number from x in direction of y.  In other words,
if y is less than x, the functions return the largest representable
floating-point number less than x.  When x equals y, the value of y is
returned.  The three functions differ only in the type of the return
value and x.

The nexttoward() and nexttowardf() functions are equivalent to the
nextafter() family of functions with two exceptions:

1.   The second parameter has a type long double.

2.   The return value is y converted to the type of the function,
provided that x equals y.

nexttowardl() is equivalent to nextafterl().

RETURN VALUES
Upon successful completion, the described functions return the next
representable floating-point value as described above.  If x is finite
but an overflow would occur, a range error follows and the functions
return +-HUGE_VAL, +-HUGE_VALF, or +-HUGE_VALL with the same sign as x.
When either x or y is NaN, a NaN is returned.  When x is not y but the
function value is subnormal, zero, or underflows, a range error occurs,
and either 0.0 or the correct function value (if representable) is
returned.

math(3)

STANDARDS
The described functions conform to ISO/IEC 9899:1999 ("ISO C99").

NetBSD 9.99                   September 13, 2015                   NetBSD 9.99
```