The Open Group Base Specifications Issue 8
IEEE Std 1003.1-2024
Copyright © 2001-2024 The IEEE and The Open Group

NAME

copysign, copysignf, copysignl — number manipulation function

SYNOPSIS

#include <math.h>

double copysign(double
x, double y);
float copysignf(float
x, float y);
long double copysignl(long double
x, long double y);

DESCRIPTION

[CX] [Option Start] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2024 defers to the ISO C standard. [Option End]

These functions shall produce a value with the magnitude of x and the sign of y. On implementations that represent a signed zero but do not treat negative zero consistently in arithmetic operations, these functions regard the sign of zero as positive.

RETURN VALUE

Upon successful completion, these functions shall return a value with the magnitude of x and the sign of y.

[MX] [Option Start] The returned value shall be exact and shall be independent of the current rounding direction mode. [Option End]

ERRORS

No errors are defined.


The following sections are informative.

EXAMPLES

None.

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

signbit

XBD <math.h>

CHANGE HISTORY

First released in Issue 6. Derived from the ISO/IEC 9899:1999 standard.

Issue 8

Austin Group Defect 1302 is applied, aligning these functions with the ISO/IEC 9899:2018 standard.

End of informative text.

 

return to top of page

UNIX® is a registered Trademark of The Open Group.
POSIX™ is a Trademark of The IEEE.
Copyright © 2001-2024 The IEEE and The Open Group, All Rights Reserved
[ Main Index | XBD | XSH | XCU | XRAT ]