COPYSIGN(3) BSD Library Functions Manual COPYSIGN(3)
NAME
copysign, copysignf, copysignl -- functions to manipulate signs
LIBRARY
Math Library (libm, -lm)
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
The copysign(), copysignf(), and copysignl() functions return a value whose absolute value matches x, but whose sign bit is taken from y.
RETURN VALUES
Upon successful completion, all three functions return a value with the magnitude of x and the sign of y. If x is NaN , the functions return
a NaN with the sign of y.
SEE ALSO
math(3), signbit(3)
STANDARDS
The described functions conform to ISO/IEC 9899:1999 (``ISO C99'').
CAVEATS
Note that on implementations that represent a signed zero but do not treat negative zero consistently in arithmetic operations, these func-
tions may regard the sign of zero as positive.
BSD
April 13, 2011 BSD
