Adds support for History data, allowing us to store specific interesting occurrences in the data flow, and recall them later.

Signed-off-by: Deukhoofd <Deukhoofd@gmail.com>

src/Battling/History/HistoryElements/AttackUseHistory.hpp

@@ -0,0 +1,24 @@
+#ifndef CREATURELIB_ATTACKUSEHISTORY_HPP
+#define CREATURELIB_ATTACKUSEHISTORY_HPP
+#include "../../Models/ExecutingAttack.hpp"
+#include "HistoryElement.hpp"
+
+namespace CreatureLib::Battling {
+    class AttackUseHistory : public HistoryElement {
+        std::unique_ptr<const ExecutingAttack> _attack;
+
+    protected:
+        void Clear() override {
+            _attack.reset();
+            HistoryElement::Clear();
+        }
+
+    public:
+        AttackUseHistory(const ExecutingAttack* attack) : _attack(attack) {}
+
+        HistoryElementKind GetKind() const noexcept override { return HistoryElementKind::AttackUse; }
+        ArbUt::BorrowedPtr<const ExecutingAttack> GetAttack() { return _attack; }
+    };
+}
+
+#endif // CREATURELIB_ATTACKUSEHISTORY_HPP

src/Battling/History/HistoryElements/HistoryElement.hpp

@@ -0,0 +1,25 @@
+#ifndef CREATURELIB_HISTORYELEMENT_HPP
+#define CREATURELIB_HISTORYELEMENT_HPP
+
+#include <Arbutils/Memory/BorrowedPtr.hpp>
+#include "../HistoryElementKind.hpp"
+namespace CreatureLib::Battling {
+    class HistoryElement {
+        friend class HistoryHolder;
+        HistoryElement* _previous;
+
+    protected:
+        virtual void Clear() {
+            if (_previous != nullptr) {
+                _previous->Clear();
+            }
+        }
+
+    public:
+        virtual HistoryElementKind GetKind() const noexcept = 0;
+        ArbUt::BorrowedPtr<const HistoryElement> GetPrevious() const noexcept { return _previous; }
+    };
+
+}
+
+#endif // CREATURELIB_HISTORYELEMENT_HPP