traits or not, isn't it all compiled down to impls? and if some are not called, they can be dropped (dead code elimination basically)? of course this would requ

traits or not, isn't it all compiled down to impls? and if some are not called, they can be dropped (dead code elimination basically)? of course this would require tracking the full call graph, right? (which the compiler might or might not do already; or might not be able to do due to memory constraints.)