Yes, I probably didn't express myself as clearly as I could have done.

Of course _any_ variable name "could possibly" be used outside a macro: macros don't come with much by way of safety features. I've been suggesting for a while that we should replace as many as we can with inline functions - which also gives type safety (as much as C has, at least), and protects against repeated evaluation of arguments - but for reasons which escape me there seems little enthusiasm for such a change.

(I briefly considered suggesting I should write an essay "macros considered harmful", but then I read Considered harmful and thought better of it.)