Introduced the xAODPrimitives.xAODIso python module.

It is meant to help python code get access to all the enumerations
in the xAOD::Iso C++ namespace.

At the same time moved the ROOT6_NamespaceAutoloadHook struct into
a more hidden place, as C++ clients don't need to be exposed to it.

Event/xAOD/xAODPrimitives/CMakeLists.txt

@@ -18,3 +18,6 @@ atlas_add_dictionary( xAODPrimitivesDict
 atlas_add_test( ut_xAOD_primitives_enums_test
    SOURCES test/ut_xAOD_primitives_enums_test.cxx
    LINK_LIBRARIES xAODPrimitives )
+
+# Install files from the package.
+atlas_install_python_modules( python/*.py )

Event/xAOD/xAODPrimitives/python/__init__.py

+# Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration

Event/xAOD/xAODPrimitives/python/xAODIso.py

+# Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
+
+# Make sure that the dictionary is loaded.
+import ROOT
+ROOT.xAOD.Iso.ROOT6_NamespaceAutoloadHook()
+
+# Declare the xAODIso type.
+xAODIso = ROOT.xAOD.Iso

Event/xAOD/xAODPrimitives/xAODPrimitives/IsolationType.h

 // Dear emacs, this is -*- c++ -*-
-
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
-
-// $Id: IsolationType.h 718726 2016-01-20 12:10:22Z dzhang $
 #ifndef XAODPRIMITIVES_ISOLATIONTYPE_H
 #define XAODPRIMITIVES_ISOLATIONTYPE_H
 
@@ -100,8 +97,6 @@ namespace xAOD {
               default:      return "[Unknown IsolationType]";
           }
       }
-
-      struct ROOT6_NamespaceAutoloadHook{};
       
    } // namespace Iso
 

Event/xAOD/xAODPrimitives/xAODPrimitives/selection.xml

-<!-- $Id: selection.xml 615648 2014-09-08 16:35:14Z schaffer $ -->
+<!-- Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration -->
 <lcgdict>
 
   <!-- Enums -->
   <enum pattern="xAOD::Iso::*" />
-  <class name="xAOD::Iso::ROOT6_NamespaceAutoloadHook" />
+  <struct name="xAOD::Iso::ROOT6_NamespaceAutoloadHook" />
 
 </lcgdict>

Event/xAOD/xAODPrimitives/xAODPrimitives/xAODPrimitivesDict.h

 // Dear emacs, this is -*- c++ -*-
-
 /*
-  Copyright (C) 2002-2017 CERN for the benefit of the ATLAS collaboration
+  Copyright (C) 2002-2020 CERN for the benefit of the ATLAS collaboration
 */
-
-// $Id: xAODPrimitivesDict.h 636772 2014-12-18 15:33:07Z mnowak $
 #ifndef XAODPRIMITIVES_XAODPRIMITIVESDICT_H
 #define XAODPRIMITIVES_XAODPRIMITIVESDICT_H
 
+// Local include(s).
 #include "xAODPrimitives/IsolationType.h"
 #include "xAODPrimitives/IsolationCorrection.h"
 #include "xAODPrimitives/IsolationFlavour.h"
 #include "xAODPrimitives/IsolationConeSize.h"
 
-#endif // XAODPRIMITIVES_XAODPRIMITIVESDICT_H
+namespace xAOD {
+   namespace Iso {
+      /// Struct helping with auto-loading this dictionary
+      struct ROOT6_NamespaceAutoloadHook {};
+   } // namespace Iso
+} // namespace xAOD
 
+#endif // XAODPRIMITIVES_XAODPRIMITIVESDICT_H