netbsd man page for copysign

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