1 files changed, 4 insertions, 1 deletions
diff --git a/Source/Core/InputCommon/ControlReference/ExpressionParser.h b/Source/Core/InputCommon/ControlReference/ExpressionParser.h
index 5b77f1b1be..c4b8a0c006 100644
--- a/Source/Core/InputCommon/ControlReference/ExpressionParser.h
+++ b/Source/Core/InputCommon/ControlReference/ExpressionParser.h
@@ -170,10 +170,13 @@ class Expression
 {
 public:
   virtual ~Expression() = default;
-  virtual ControlState GetValue() const = 0;
+  virtual ControlState GetValue() = 0;
   virtual void SetValue(ControlState state) = 0;
   virtual int CountNumControls() const = 0;
   virtual void UpdateReferences(ControlEnvironment& finder) = 0;
+
+  // Perform any side effects and return Expression to be SetValue'd.
+  virtual Expression* GetLValue();
 };
 
 class ParseResult