XtOffset(3Xt)

     NAME
          XtOffset, XtOffsetOf, XtNumber - determine the byte offset
          or number of array elements

     SYNTAX
          Cardinal XtOffset(pointer_type, field_name)
                Type pointer_type;
                Field field_name;

          Cardinal XtOffsetOf(structure_type, field_name)
                Type structure_type;
                Field field_name;

          Cardinal XtNumber(array)
                ArrayVariable array;

     ARGUMENTS
          array     Specifies a fixed-size array.

          field_name
                    Specifies the name of the field for which to
                    calculate the byte offset.

          pointer_type
                    Specifies a type that is declared as a pointer to
                    the structure.

          structure_type
                    Specifies a type that is declared as a structure.

     DESCRIPTION
          The XtOffset macro is usually used to determine the offset
          of various resource fields from the beginning of a widget
          and can be used at compile time in static initializations.

          The XtOffsetOf macro expands to a constant expression that
          gives the offset in bytes to the specified structure member
          rom the beginning of the structure.  It is normally used to
          statically initialize resource lists and is more portable
          than XtOffset, which serves the same function.

          The XtNumber macro returns the number of elements in the
          specified argument lists, resources lists, and other counted
          arrays.

     SEE ALSO
          XtGetResourceList(3Xt), XtSetArg(3Xt)
          X Toolkit Intrinsics - C Language Interface
          Xlib - C Language X Interface