copysign, copysignf, copysignl — number manipulation function
#include <math.h>
double copysign(double x, double y);
float copysignf(float x, float y);
long double copysignl(long double x, long double y);
[CX] 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.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.
Upon successful completion, these functions shall return a value with the magnitude of x and the sign of y.
[MX] The returned value shall be exact and shall be independent of the current rounding direction mode.
No errors are defined.
None.
None.
None.
None.
XBD <math.h>
First released in Issue 6. Derived from the ISO/IEC 9899:1999 standard.
Austin Group Defect 1302 is applied, aligning these functions with the ISO/IEC 9899:2018 standard.
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