On 05/07/11 23:56, kevin diggs wrote: > Hi, > > On Mon, Jul 4, 2011 at 12:07 PM, Andrew Haley <aph@xxxxxxxxxx> wrote: >> >> It's not. Tey're wrong, you're right. >> >> Hope this helps. :-) >> >> Andrew. >> > > What about this: > > #include <math.h> > > #define MASK ((unsigned short) 0x8000) > > double copysign (double x, double y) > { > unsigned short * const py = (unsigned short*)(char*)&y + 3; > > return fabs(x)*(*py&MASK?-1.0:1.0); > } What are you asking? It's still not legal, if that was the question. Using just a char* would be OK, though. Andrew.