-index. If C<lval> is set then the fetch will be part of a store. Check
-that the return value is non-null before dereferencing it to a C<SV*>.
+index. If lval is true, you are guaranteed to get a real SV back (in case
+it wasn't real before), which you can then modify. Check that the return
+value is non-null before dereferencing it to a C<SV*>.