+ // rustc doesn't like <_> if the _ is actually a lifetime, so
+ // if all the parameters are lifetimes just skip it.
+ let mut nonlifetime_param = false;
+ for param in $trait.generics.params.iter() {
+ if let syn::GenericParam::Lifetime(_) = param {}
+ else { nonlifetime_param = true; }
+ }
+ if !nonlifetime_param { t_gen_args = String::new(); }