Comments on oneShot

compiler/basicTypes/MkId.hs

@@ -1326,6 +1326,10 @@ and Note [Left folds via right fold]) it was determined that it would be useful
 if library authors could explicitly tell the compiler that a certain lambda is
 called at most once. The oneShot function allows that.
 
+'oneShot' is open kinded, i.e. the type variables can refer to unlifted
+types as well (Trac #10744); e.g.
+   oneShot (\x:Int# -> x +# 1#)
+
 Like most magic functions it has a compulsary unfolding, so there is no need
 for a real definition somewhere. We have one in GHC.Magic for the convenience
 of putting the documentation there.