Easy possibility to store condition payloads as std::any #927

MarkusFrankATcernch · 2022-07-09T19:04:41Z

BEGINRELEASENOTES
Easy possibility to store condition payloads as std::any.

Use of specialized handle class dd4hep::ConditionAny to support the functionality.
The payload is automatically bound to an object of type std::any.
Example code of constructor and how to access data:
```
/// Emplacement construction
std::vector<int> value;
... // fill data
ConditionAny c2("name", "type", std::move(value));

/// Construct conditions object with empty std::any	 
ConditionAny c2("name", "type");
/// Assign data (empty vector<int>) to the payload:
c2.get() = vector<int>();

/// Access data:
vector<int>& data = c2.as<vector<int> >();
```
as a corollary to this approach these conditions can only be stored and retrieved from ROOT storage
if the requirement for ROOT are satisfied. Otherwise no other restrictions are imposed.
The corresponding grammar instance is part of the library.
Add example to illustrate the functionality in example/conditions:
o examples/Conditions/src/ConditionAnyExampleObjects.cpp
o examples/Conditions/src/ConditionAnyExampleObjects.h
o plugin: examples/Conditions/src/ConditionAnyExample_populate.cpp
Invocation:

   $> geoPluginRun  -destroy -plugin DD4hep_ConditionAnyExample_populate \
        -input ../../DD4hep/examples/AlignDet/compact/Telescope.xml -iovs 1

Plugin example to test basic functionality and verify proper assignment works
o examples/Conditions/src/Conditions_any_basic.cpp
Invocation:

$> geoPluginRun -destroy -volmgr -plugin DD4hep_Conditions_any_basic

Add 2 tests illustrating this functionality.
ENDRELEASENOTES

sponce · 2022-07-20T06:54:46Z

DDCore/include/DD4hep/ConditionAny.h

+#ifndef DD4HEP_CONDITIONANY_H
+#define DD4HEP_CONDITIONANY_H


Why not using #pragma once rather than playing with names that will unavoidably collide one day ?

sponce · 2022-07-20T06:58:14Z

DDCore/include/DD4hep/ConditionAny.h

+    /// Flag operations: Get condition flags
+    mask_type flags()  const;
+    /// Flag operations: Set a conditons flag
+    void setFlag(mask_type option);
+    /// Flag operations: UN-Set a conditons flag
+    void unFlag(mask_type option);
+    /// Flag operations: Test for a given a conditons flag
+    bool testFlag(mask_type option) const;
+


For what I see in this MR, these functions are never used. Is this correct ? If yes, why to add them ?

sponce · 2022-07-20T07:00:57Z

DDG4/plugins/Geant4FastPhysics.cpp

@@ -0,0 +1,107 @@
+//==========================================================================
