The Single UNIX ® Specification, Version 2
Copyright © 1997 The Open Group

 NAME

nextafter - next representable double-precision floating-point number

 SYNOPSIS



#include <math.h>

double nextafter(double x, double y);

 DESCRIPTION

The nextafter() function computes the next representable double-precision floating-point value following x in the direction of y. Thus, if y is less than x, nextafter() returns the largest representable floating-point number less than x.

An application wishing to check for error situations should set errno to 0 before calling nextafter(). If errno is non-zero on return, or the value NaN is returned, an error has occurred.

 RETURN VALUE

The nextafter() function returns the next representable double-precision floating-point value following x in the direction of y.

If x or y is NaN, then nextafter() returns NaN and may set errno to [EDOM].

If x is finite and the correct function value would overflow, HUGE_VAL is returned and errno is set to [ERANGE].

 ERRORS

The nextafter() function will fail if:
[ERANGE]
The correct value would overflow.

The nextafter() function may fail if:

[EDOM]
The x or y argument is NaN.

 EXAMPLES

None.

 APPLICATION USAGE

None.

 FUTURE DIRECTIONS

None.

 SEE ALSO

<math.h>.

UNIX ® is a registered Trademark of The Open Group.
Copyright © 1997 The Open Group
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