diff --git a/compiler/NubLang/Generation/QBE/QBEGenerator.cs b/compiler/NubLang/Generation/QBE/QBEGenerator.cs
index 99e9319..0601506 100644
--- a/compiler/NubLang/Generation/QBE/QBEGenerator.cs
+++ b/compiler/NubLang/Generation/QBE/QBEGenerator.cs
@@ -294,6 +294,7 @@ public class QBEGenerator
         return size;
     }
 
+    // todo(nub31): EmitRValue should take a destination parameter so we can skip copying rvalues
     private void EmitCopyInto(ExpressionNode source, string destination)
     {
         if (source.Type.IsScalar)