double to hex string & hex string to double

Question

What I\'m trying to do is to convert a double to hex string and then back to double.

The following code does conversion double-to-hex string.

char *          


        

Answer 1

Almost the same procedure should do

void hex2double(const char* buf, double& a)
{
   char tmpbuf[3]={0};
   char *d2c;
   unsigned int tmp;
   d2c = (char *) &a;
   char *n = buf;
   int i;
   for(i = 0; i < 8; i++)
   {
      tmpbuf[0]=*buf++;
      tmpbuf[1]=*buf++;
      sscanf(tmpbuf, "%X", &tmp);
      *d2c++=tmp;
   }
}

Quick & dirty.

Note, however, that this is playing with fire. First, your hex strings are only usable on machines with the same double format, and the same endianness. Second, the conversion functions are short on strict aliasing rule.