Return a typed pointer if possible

Author: tmadlener

include/podio/Frame.h

@@ -220,7 +220,7 @@ class Frame {
   /// @returns A const pointer to a collection if it is available or a nullptr
   ///          if it is not
   template <ObjectType O>
-  inline const podio::CollectionBase* get(const O& object) const;
+  inline const typename O::collection_type* get(const O& object) const;
 
   /// (Destructively) move a collection into the Frame and get a reference to
   /// the inserted collection back for further use.
@@ -416,9 +416,9 @@ inline const podio::CollectionBase* Frame::get(const std::string& name) const {
 }
 
 template <ObjectType O>
-inline const podio::CollectionBase* Frame::get(const O& object) const {
+inline const typename O::collection_type* Frame::get(const O& object) const {
   const auto name = m_self->getIDTable().name(object.id().collectionID);
-  return get(name.value_or(""));
+  return dynamic_cast<const typename O::collection_type*>(get(name.value_or("")));
 }
 
 inline void Frame::put(std::unique_ptr<podio::CollectionBase> coll, const std::string& name) {

tests/unittests/frame.cpp

@@ -444,10 +444,9 @@ TEST_CASE("Frame get from object", "[frame][basics]") {
   REQUIRE(frameClusters[0] == objectClusters[0]);
 
   const auto* collPtr = event.get(cluster);
+  STATIC_REQUIRE(std::is_same_v<decltype(collPtr), const ExampleClusterCollection*>);
   REQUIRE(collPtr != nullptr);
-  const auto* clusterCollPtr = dynamic_cast<const ExampleClusterCollection*>(collPtr);
-  REQUIRE(clusterCollPtr != nullptr);
-  REQUIRE((*clusterCollPtr)[0] == cluster);
+  REQUIRE((*collPtr)[0] == cluster);
 }
 
 TEST_CASE("EIC-Jana2 cleanup use case", "[memory-management][492][174]") {