Codefix: add doxygen for DefaultSaveLoadHandler (#15186)

src/saveload/saveload.h

@@ -537,7 +537,7 @@ using SaveLoadCompatTable = std::span<const struct SaveLoadCompat>;
 /** Handler for saving/loading an object to/from disk. */
 class SaveLoadHandler {
 public:
-	std::optional<std::vector<SaveLoad>> load_description;
+	std::optional<std::vector<SaveLoad>> load_description; ///< Description derived from savegame being loaded.
 
 	virtual ~SaveLoadHandler() = default;
 
@@ -567,11 +567,13 @@ public:
 
 	/**
 	 * Get the description of the fields in the savegame.
+	 * @return Save load description.
 	 */
 	virtual SaveLoadTable GetDescription() const = 0;
 
 	/**
 	 * Get the pre-header description of the fields in the savegame.
+	 * @return Compatibility save load description.
 	 */
 	virtual SaveLoadCompatTable GetCompatDescription() const = 0;
 
@@ -598,17 +600,34 @@ template <class TImpl, class TObject>
 class DefaultSaveLoadHandler : public SaveLoadHandler {
 public:
 	SaveLoadTable GetDescription() const override { return static_cast<const TImpl *>(this)->description; }
+
 	SaveLoadCompatTable GetCompatDescription() const override { return static_cast<const TImpl *>(this)->compat_description; }
 
+	/**
+	 * Save the object to disk.
+	 * @param object The object to store.
+	 */
 	virtual void Save([[maybe_unused]] TObject *object) const {}
 	void Save(void *object) const override { this->Save(static_cast<TObject *>(object)); }
 
+	/**
+	 * Load the object from disk.
+	 * @param object The object to load.
+	 */
 	virtual void Load([[maybe_unused]] TObject *object) const {}
 	void Load(void *object) const override { this->Load(static_cast<TObject *>(object)); }
 
+	/**
+	 * Similar to load, but used only to validate savegames.
+	 * @param object The object to load.
+	 */
 	virtual void LoadCheck([[maybe_unused]] TObject *object) const {}
 	void LoadCheck(void *object) const override { this->LoadCheck(static_cast<TObject *>(object)); }
 
+	/**
+	 * A post-load callback to fix #SL_REF integers into pointers.
+	 * @param object The object to fix.
+	 */
 	virtual void FixPointers([[maybe_unused]] TObject *object) const {}
 	void FixPointers(void *object) const override { this->FixPointers(static_cast<TObject *>(object)); }
 };