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.

To use this function, link in the math library by specifying −lm on the compiler or linker command line. 

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, nextafter() returns NaN. 

If x is finite and the correct function value would overflow, nextafter() returns ±HUGE_VAL (according to the sign of x) and sets errno to [ERANGE]. 

ERRORS

If nextafter() fails, errno is set to the following value. 

[ERANGE] The correct value would overflow. 

SEE ALSO

isinf(3M), isnan(3M), limits(5). 

STANDARDS CONFORMANCE

nextafter(): SVID3, XPG4.2

Hewlett-Packard Company  —  HP-UX Release 10.20:  July 1996