[gtkmm] Gtk::MenuShell: Initialize a data member in the class declaration

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 64841054c67279b59fc848f3cd61362a59665768
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Wed Nov 27 17:00:16 2019 +0100

    Gtk::MenuShell: Initialize a data member in the class declaration
    
    MenuShell::accel_window_ is initialized in the class declaration instead
    of in every constructor. More constructors can be generated by gmmproc.

 gtk/src/menushell.ccg | 18 +-----------------
 gtk/src/menushell.hg  |  3 +--
 2 files changed, 2 insertions(+), 19 deletions(-)
---
diff --git a/gtk/src/menushell.ccg b/gtk/src/menushell.ccg
index 7b693529..e53c5306 100644
--- a/gtk/src/menushell.ccg
+++ b/gtk/src/menushell.ccg
@@ -21,25 +21,9 @@
 namespace Gtk
 {
 
-// All ctors are manually implemented just to initialize accel_window_.
-
 MenuShell::MenuShell()
 :
-  _CONSTRUCT_SPECIFIC(Gtk::Container, MenuShell),
-  accel_window_ (nullptr)
-{}
-
-MenuShell::MenuShell(const Glib::ConstructParams& construct_params)
-:
-  Glib::ObjectBase(nullptr),
-  Gtk::Container  (construct_params),
-  accel_window_   (nullptr)
-{}
-
-MenuShell::MenuShell(GtkMenuShell* castitem)
-:
-  Gtk::Container((GtkContainer*) castitem),
-  accel_window_ (nullptr)
+  _CONSTRUCT_SPECIFIC(Gtk::Container, MenuShell)
 {}
 
 // Why do we need a custom dtor?
diff --git a/gtk/src/menushell.hg b/gtk/src/menushell.hg
index e15b0bec..e639cf89 100644
--- a/gtk/src/menushell.hg
+++ b/gtk/src/menushell.hg
@@ -125,7 +125,6 @@ public:
 
 protected:
   MenuShell();
-  _CUSTOM_CTOR_CAST()
 
 private:
 
@@ -138,7 +137,7 @@ dnl // Override GtkMenuItem::insert, in order to accelerate all menu items autom
   _POP()
 #m4end
 
-  Gtk::Window*  accel_window_;
+  Gtk::Window* accel_window_ = nullptr;
 };
 
 } // namespace Gtk