From 2d4f5b43b3adb7f2e00f449cb5f2ea0fa8386723 Mon Sep 17 00:00:00 2001
From: tmadlener <thomas.madlener@desy.de>
Date: Wed, 25 Sep 2024 16:35:20 +0200
Subject: [PATCH] Use unique_ptr to manage one to one relations

---
 include/podio/detail/RelationIOHelpers.h       | 13 ++++++++-----
 python/templates/Obj.cc.jinja2                 |  6 +-----
 python/templates/Obj.h.jinja2                  |  5 ++++-
 python/templates/macros/implementations.jinja2 |  5 ++---
 4 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/include/podio/detail/RelationIOHelpers.h b/include/podio/detail/RelationIOHelpers.h
index 1ef2ee0ca..36dd4de34 100644
--- a/include/podio/detail/RelationIOHelpers.h
+++ b/include/podio/detail/RelationIOHelpers.h
@@ -4,6 +4,7 @@
 #include "podio/utilities/TypeHelpers.h"
 #include <podio/CollectionBase.h>
 
+#include <memory>
 #include <tuple>
 #include <vector>
 
@@ -109,9 +110,10 @@ void addMultiRelation(std::vector<RelType>& relElements, const podio::Collection
 /// @param coll The collection that holds the actual element
 /// @param id The ObjectID of the element that we are currently looking for
 template <typename T, typename InterfaceType>
-void tryAssignTo(T, InterfaceType*& relation, const podio::CollectionBase* coll, const podio::ObjectID id) {
+void tryAssignTo(T, std::unique_ptr<InterfaceType>& relation, const podio::CollectionBase* coll,
+                 const podio::ObjectID id) {
   if (const auto* typeColl = dynamic_cast<const typename T::collection_type*>(coll)) {
-    relation = new InterfaceType((*typeColl)[id.index]);
+    relation = std::make_unique<InterfaceType>((*typeColl)[id.index]);
   }
 }
 
@@ -129,7 +131,7 @@ void tryAssignTo(T, InterfaceType*& relation, const podio::CollectionBase* coll,
 /// @param coll The collection that holds the actual element
 /// @param id The ObjectID of the element that we are currently looking for
 template <typename InterfaceType>
-void addInterfaceToSingleRelation(InterfaceType*& relation, const podio::CollectionBase* coll,
+void addInterfaceToSingleRelation(std::unique_ptr<InterfaceType>& relation, const podio::CollectionBase* coll,
                                   const podio::ObjectID id) {
   std::apply([&](auto... t) { (tryAssignTo(t, relation, coll, id), ...); }, typename InterfaceType::interfaced_types{});
 }
@@ -162,12 +164,13 @@ void addInterfaceToSingleRelation(InterfaceType*& relation, const podio::Collect
 ///             necessary type casting
 /// @param id The ObjectID of the object that should be retrieved and added.
 template <typename RelType>
-void addSingleRelation(RelType*& relation, const podio::CollectionBase* coll, const podio::ObjectID id) {
+void addSingleRelation(std::unique_ptr<RelType>& relation, const podio::CollectionBase* coll,
+                       const podio::ObjectID id) {
   if constexpr (podio::detail::isInterfaceType<RelType>) {
     addInterfaceToSingleRelation(relation, coll, id);
   } else {
     const auto* typeColl = static_cast<const typename RelType::collection_type*>(coll);
-    relation = new RelType((*typeColl)[id.index]);
+    relation = std::make_unique<RelType>((*typeColl)[id.index]);
   }
 }
 
diff --git a/python/templates/Obj.cc.jinja2 b/python/templates/Obj.cc.jinja2
index b127fcce7..357f3a304 100644
--- a/python/templates/Obj.cc.jinja2
+++ b/python/templates/Obj.cc.jinja2
@@ -39,7 +39,7 @@
 {
 {% for relation in OneToOneRelations %}
   if (other.m_{{ relation.name }}) {
-    m_{{ relation.name }} = new {{ relation.full_type }}(*(other.m_{{ relation.name }}));
+    m_{{ relation.name }} = std::make_unique<{{ relation.full_type }}>(*(other.m_{{ relation.name }}));
   }
 {% endfor %}
 }
@@ -55,10 +55,6 @@
   }
 {% endif %}
 {%- endwith %}
-
-{% for relation in OneToOneRelations %}
-  delete m_{{ relation.name }};
-{% endfor %}
 }
 {%- endif %}
 
diff --git a/python/templates/Obj.h.jinja2 b/python/templates/Obj.h.jinja2
index f7a98ec38..90a491bb9 100644
--- a/python/templates/Obj.h.jinja2
+++ b/python/templates/Obj.h.jinja2
@@ -13,6 +13,9 @@
 #include "podio/ObjectID.h"
 {% if OneToManyRelations or VectorMembers %}
 #include <vector>
+{% endif %}
+{% if OneToOneRelations %}
+#include <memory>
 {%- endif %}
 
 {{ utils.forward_decls(forward_declarations_obj) }}
@@ -42,7 +45,7 @@ public:
   podio::ObjectID id;
   {{ class.bare_type }}Data data;
 {% for relation in OneToOneRelations %}
-  {{ relation.full_type }}* m_{{ relation.name }}{nullptr};
+  std::unique_ptr<{{ relation.full_type }}> m_{{ relation.name }}{nullptr};
 {% endfor %}
 {% for relation in OneToManyRelations + VectorMembers %}
   std::vector<{{ relation.full_type }}>* m_{{ relation.name }}{nullptr};
diff --git a/python/templates/macros/implementations.jinja2 b/python/templates/macros/implementations.jinja2
index 530843c48..0dd16adeb 100644
--- a/python/templates/macros/implementations.jinja2
+++ b/python/templates/macros/implementations.jinja2
@@ -38,7 +38,7 @@ Mutable{{ type }} {{ full_type }}::clone(bool cloneRelations) const {
   if (cloneRelations) {
 {% for relation in one_to_one_relations %}
   if (m_obj->m_{{ relation.name }}) {
-    tmp->m_{{ relation.name }} = new {{ relation.full_type }}(*m_obj->m_{{ relation.name }});
+    tmp->m_{{ relation.name }} = std::make_unique<{{ relation.full_type }}>((*m_obj->m_{{ relation.name }}));
   }
 {% endfor %}
 {% for relation in multi_relations %}
@@ -124,8 +124,7 @@ const {{ relation.full_type }} {{ class_type }}::{{ relation.getter_name(get_syn
 {% set class_type = prefix + class.bare_type %}
 {% for relation in relations %}
 void {{ class_type }}::{{ relation.setter_name(get_syntax) }}(const {{ relation.full_type }}& value) {
-  delete m_obj->m_{{ relation.name }};
-  m_obj->m_{{ relation.name }} = new {{ relation.full_type }}(value);
+  m_obj->m_{{ relation.name }} = std::make_unique<{{ relation.full_type }}>(value);
 }
 
 {% endfor %}