Dealing with C Structures with bit-field members

I would like to translate some c headers files but I am unsure of how to approach the members variables defined with the size of a certain number of bits. For example

Code:

 
struct _GtkWindow
{
  GtkBin bin;

  gchar *title;
  gchar *wmclass_name;
  gchar *wmclass_class;
  gchar *wm_role;

  GtkWidget *focus_widget;
  GtkWidget *default_widget;
  GtkWindow *transient_parent;
  GtkWindowGeometryInfo *geometry_info;
  GdkWindow *frame;
  GtkWindowGroup *group;

  guint16 configure_request_count;
  guint allow_shrink : 1;
  guint allow_grow : 1;
  guint configure_notify_received : 1;
  /* The following flags are initially TRUE (before a window is mapped).
   * They cause us to compute a configure request that involves
   * default-only parameters. Once mapped, we set them to FALSE.
   * Then we set them to TRUE again on unmap (for position)
   * and on unrealize (for size).
   */
  guint need_default_position : 1;
  guint need_default_size : 1;
  guint position : 3;
  guint type : 4; /* GtkWindowType */ 
  guint has_user_ref_count : 1;
  guint has_focus : 1;

  guint modal : 1;
  guint destroy_with_parent : 1;
  
  guint has_frame : 1;

  /* gtk_window_iconify() called before realization */
  guint iconify_initially : 1;
  guint stick_initially : 1;
  guint maximize_initially : 1;
  guint decorated : 1;
  
  guint type_hint : 3; /* GdkWindowTypeHint */ 
  guint gravity : 5; /* GdkGravity */

  guint is_active : 1;
  guint has_toplevel_focus : 1;
  
  guint frame_left;
  guint frame_top;
  guint frame_right;
  guint frame_bottom;

  guint keys_changed_handler;
  
  GdkModifierType mnemonic_modifier;
  GdkScreen      *screen;
};

What I would like is a way to declare the fields so that they can be accessed transparently as would be possible in C. At the moment they way I intend to solve the problem is just count the total number of bits for each member and declare a generic variable big enough for the fields. This way the if I follow the gtk reference and use a structure member that is a bit field, fasm will alert me of the error and I could verify whats going on according to how the structure was translated. This is what I have come up with so far. Is it an ok solution or can it be done better?