Config: Add [[nodiscard]] to AddConfigChangedCallback

Require callers of Config::AddConfigChangedCallback and
CPUThreadConfigCallback::AddConfigChangedCallback to handle the returned
ConfigChangedCallbackIDs to hopefully prevent future issues with
callbacks getting called after their associated objects have been
destroyed.

1 files changed, 3 insertions, 3 deletions

diff --git a/Source/Core/Common/Config/Config.h b/Source/Core/Common/Config/Config.h
index d7b370282a..ea6058a8d3 100644
--- a/Source/Core/Common/Config/Config.h
+++ b/Source/Core/Common/Config/Config.h
@@ -29,9 +29,9 @@ void AddLayer(std::unique_ptr<ConfigLayerLoader> loader);
 std::shared_ptr<Layer> GetLayer(LayerType layer);
 void RemoveLayer(LayerType layer);
 
-// Returns an ID that can be passed to RemoveConfigChangedCallback().
-// The callback may be called from any thread.
-ConfigChangedCallbackID AddConfigChangedCallback(ConfigChangedCallback func);
+// Returns an ID that should be passed to RemoveConfigChangedCallback() when the callback is no
+// longer needed. The callback may be called from any thread.
+[[nodiscard]] ConfigChangedCallbackID AddConfigChangedCallback(ConfigChangedCallback func);
 void RemoveConfigChangedCallback(ConfigChangedCallbackID callback_id);
 void OnConfigChanged();