[gtkmm] convert_gdk.m4: Use of static_cast<>.

[Murray Cumming <murrayc src gnome org>]

commit c1543ba330e8fad7cf0f3c4c53a50e074129f29d
Author: Murray Cumming <murrayc murrayc com>
Date:   Sat May 6 22:35:39 2017 +0200

    convert_gdk.m4: Use of static_cast<>.

 tools/m4/convert_gdk.m4 |   12 ++++++------
 1 files changed, 6 insertions(+), 6 deletions(-)
---
diff --git a/tools/m4/convert_gdk.m4 b/tools/m4/convert_gdk.m4
index 4ce5c39..fe66678 100644
--- a/tools/m4/convert_gdk.m4
+++ b/tools/m4/convert_gdk.m4
@@ -243,7 +243,7 @@ _CONVERSION(`GdkMonitor*',`Glib::RefPtr<const Monitor>', `Glib::wrap($3)')
 _CONVERSION(`GdkDeviceManager*',`Glib::RefPtr<DeviceManager>', `Glib::wrap($3)')
 _CONVERSION(`GdkDeviceManager*',`Glib::RefPtr<const DeviceManager>', `Glib::wrap($3)')
 
-_CONVERSION(`gpointer',`const void*', `($2)($3)')
+_CONVERSION(`gpointer',`const void*', `static_cast<$2>($3)')
 
 
 # Glib::ListHandle<> (gdkmm) -> GList (gdk)
@@ -284,11 +284,11 @@ _CONVERSION(`const Glib::ustring&', `GdkAtom', `Gdk::AtomString::to_c_type($3)')
 _CONVERSION(`Glib::ustring&',`GdkAtom',`Gdk::AtomString::to_c_type($3)')
 
 dnl NativeWindow
-_CONVERSION(`GdkNativeWindow',`Gdk::NativeWindow',`($2)($3)')
-_CONVERSION(`GdkNativeWindow',`NativeWindow',`($2)($3)')
-_CONVERSION(`Gdk::NativeWindow',`GdkNativeWindow',`($2)($3)')
-_CONVERSION(`NativeWindow',`GdkNativeWindow',`($2)($3)')
-_CONVERSION(`GdkEvent*',`const GdkEvent*',`($2)($3)')
+_CONVERSION(`GdkNativeWindow',`Gdk::NativeWindow',`static_cast<$2>($3)')
+_CONVERSION(`GdkNativeWindow',`NativeWindow',`static_cast<$2>($3)')
+_CONVERSION(`Gdk::NativeWindow',`GdkNativeWindow',`static_cast<$2>($3)')
+_CONVERSION(`NativeWindow',`GdkNativeWindow',`static_cast<$2>($3)')
+_CONVERSION(`GdkEvent*',`const GdkEvent*',`($3)')
 
 
 _CONVERSION(`GdkDragContext*',`Glib::RefPtr<DragContext>',Glib::wrap($3, true))