/**
 * call-seq:
 *     set_result_error( func, string ) -> string
 *
 * Sets the result of the given function to be the error message given in the
 * +string+ parameter. The +func+ parameter must be an opaque function handle
 * as given to the callback function for #create_function or
 * #create_aggregate.
 */
static VALUE
static_api_set_result_error( VALUE module, VALUE func, VALUE string )
{
  sqlite_func *func_ptr;

  GetFunc( func_ptr, func );
  Check_Type( string, T_STRING );

  sqlite_set_result_error( func_ptr, RSTRING(string)->ptr,
    RSTRING(string)->len );

  return string;
}