Originální popis anglicky:
copysign, copysignf, copysignl - copy sign of a number
Návod, kniha: Linux Programmer's Manual
#include <math.h>
double copysign(double x, double y);
float copysignf(float x, float y);
long double copysignl(long double x, long double y);
Link with -lm.
The
copysign() functions return a value whose absolute value matches that
of
x, but whose sign matches that of
y. If
x is a NaN,
then a NaN with the sign of
y is returned.
The
copysign() functions may treat a negative zero as positive.
C99, BSD 4.3. This function is defined in IEC 559 (and the appendix with
recommended functions in IEEE 754/IEEE 854).
signbit(3)
