4 pub fn type_visitable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
5 if let syn::Data::Union(_) = s.ast().data {
6 panic!("cannot derive on union")
9 if !s.ast().generics.lifetimes().any(|lt| lt.lifetime.ident == "tcx") {
10 s.add_impl_generic(parse_quote! { 'tcx });
13 s.add_bounds(synstructure::AddBounds::Generics);
14 let body_visit = s.each(|bind| {
16 ::rustc_middle::ty::visit::TypeVisitable::visit_with(#bind, __visitor)?;
19 s.bind_with(|_| synstructure::BindStyle::Move);
22 quote!(::rustc_middle::ty::visit::TypeVisitable<'tcx>),
24 fn visit_with<__V: ::rustc_middle::ty::visit::TypeVisitor<'tcx>>(
27 ) -> ::std::ops::ControlFlow<__V::BreakTy> {
28 match *self { #body_visit }
29 ::std::ops::ControlFlow::CONTINUE