|COPYSIGN(3)||Linux Programmer's Manual||COPYSIGN(3)|
NAMEcopysign, copysignf, copysignl - copy sign of a number
double copysign(double x , double y );
float copysignf(float x , float y );
long double copysignl(long double x , long double y );
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
_SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE >= 600 || _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L;or cc -std=c99
DESCRIPTIONThe copysign() functions return a value whose absolute value matches that of x, but whose sign bit matches that of y.
RETURN VALUEOn success, these functions return a value whose magnitude is taken from x and whose sign is taken from y.
ERRORSNo errors occur.
CONFORMING TOC99, POSIX.1-2001. This function is defined in IEC 559 (and the appendix with recommended functions in IEEE 754/IEEE 854).
NOTESOn architectures where the floating-point formats are not IEEE 754 compliant, the copysign() functions may treat a negative zero as positive.
COLOPHONThis page is part of release 3.53 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.