From 4668a95cbc6263c990a4eb57ddc6a6c1afdaed26 Mon Sep 17 00:00:00 2001
From: Bohdan Dudar <bohdan.dudar@desy.de>
Date: Wed, 31 Aug 2022 13:43:25 +0200
Subject: [PATCH] Add a utility function to return objects index inside a
 provided LCCollection

---
 src/cpp/include/UTIL/LCCollectionTools.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 src/cpp/include/UTIL/LCCollectionTools.h

diff --git a/src/cpp/include/UTIL/LCCollectionTools.h b/src/cpp/include/UTIL/LCCollectionTools.h
new file mode 100644
index 000000000..aa3e8580d
--- /dev/null
+++ b/src/cpp/include/UTIL/LCCollectionTools.h
@@ -0,0 +1,20 @@
+#ifndef UTIL_LCCollectionTools_H
+#define UTIL_LCCollectionTools_H 1
+
+#include "EVENT/LCObject.h"
+#include "EVENT/LCCollection.h"
+
+namespace UTIL{
+    /** Extract object index inside a given LCCollection.
+    * @author Bohdan Dudar
+    * @version August 2022
+    */
+    int getElementIndex(const EVENT::LCObject* item, EVENT::LCCollection* collection){
+        for(int i=0; i < collection->getNumberOfElements(); ++i){
+            if ( item == collection->getElementAt(i) ) return i;
+        }
+        return -1;
+    }
+}
+
+#endif