Serializes and deserializes VAX and IEEE double-precision
    floating-point numbers.
    Format
      #include  <tcpip$rpcxdr.h>
      bool_t  xdr_double(XDR *xdrs, double *dp);
1 – Arguments
 xdrs
    A pointer to an XDR stream handle created by one of the XDR
    stream-handle creation routines.
 dp
    A pointer to the double-precision floating-point number.
2 – Description
    A filter primitive that translates between double-precision
    numbers and their external representations.
    This routine is implemented by four XDR routines:
    xdr_       Converts VAX D-format floating-point numbers.
    double_D
    xdr_       Converts VAX G-format floating-point numbers.
    double_G
    xdr_       Converts IEEE T-format floating-point numbers.
    double_T
    xdr_       Converts IEEE X-format floating-point numbers.
    double_X
    You can reference these routines explicitly or you can use
    compiler settings to control which routine is used when you
    reference the xdr_double routine.
3 – Return Values
    TRUE               Indicates success.
    FALSE              Indicates failure.