4 #![crate_type = "proc-macro"]
6 extern crate proc_macro;
8 use proc_macro::TokenStream;
10 #[proc_macro_attribute]
11 pub fn foo(attr: TokenStream, item: TokenStream) -> TokenStream {
13 assert_eq!(item.to_string(), "fn foo() {}");
14 "fn foo(&self);".parse().unwrap()