Core/Utils: Added a custom smart pointer type unique_trackable_ptr - a specialized variant of std::shared_ptr that enforces unique ownership

* This is intended to be used by external code unable to track object lifetime such as custom scripting engines

(cherry picked from commit 32e54b6bd168c196adb45360b18721851162d731)

1 files changed, 90 insertions, 0 deletions

diff --git a/tests/common/UniqueTrackablePtr.cpp b/tests/common/UniqueTrackablePtr.cpp
new file mode 100644
index 00000000000..6a1db9fa277
--- /dev/null
+++ b/tests/common/UniqueTrackablePtr.cpp
@@ -0,0 +1,90 @@
+/*
+ * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "tc_catch2.h"
+
+#include "UniqueTrackingPtr.h"
+
+struct TestObj
+{
+    TestObj(bool* deleted = nullptr) : Deleted(deleted) { }
+
+    ~TestObj()
+    {
+        if (Deleted)
+            *Deleted = true;
+    }
+
+    bool* Deleted = nullptr;
+};
+
+TEST_CASE("Trinity::unique_trackable_ptr frees memory", "[UniqueTrackingPtr]")
+{
+    bool deleted = false;
+
+    SECTION("reassigning new object deletes old one")
+    {
+        Trinity::unique_trackable_ptr<TestObj> ptr = Trinity::make_unique_trackable<TestObj>(&deleted);
+
+        ptr.reset(new TestObj());
+
+        REQUIRE(deleted == true);
+    }
+
+    SECTION("going out of scope deletes object")
+    {
+        REQUIRE(deleted == false);
+
+        {
+            Trinity::unique_trackable_ptr<TestObj> ptr = Trinity::make_unique_trackable<TestObj>(&deleted);
+        }
+
+        REQUIRE(deleted == true);
+    }
+}
+
+TEST_CASE("Trinity::unique_weak_ptr", "[UniqueTrackingPtr]")
+{
+    Trinity::unique_trackable_ptr<int> ptr = Trinity::make_unique_trackable<int>();
+
+    Trinity::unique_weak_ptr<int> weakRef = ptr;
+
+    SECTION("when unique_trackable_ptr no longer holds a value then weak cannot retrieve it")
+    {
+        ptr.reset();
+
+        REQUIRE(weakRef.expired());
+        REQUIRE(!weakRef.lock());
+    }
+
+    SECTION("when unique_trackable_ptr is reassigned then weak cannot retrieve old value")
+    {
+        ptr.reset(new int);
+
+        Trinity::unique_weak_ptr<int> weakRef2 = ptr;
+
+        REQUIRE(weakRef.expired());
+        REQUIRE(!weakRef2.expired());
+        REQUIRE(weakRef.lock() != weakRef2.lock());
+    }
+
+    SECTION("when unique_trackable_ptr holds a value then weak can retrieve it")
+    {
+        REQUIRE(!weakRef.expired());
+        REQUIRE(!!weakRef.lock());
+    }
+}