//@ force-host //@ no-prefer-dynamic #![crate_type = "proc-macro"] extern crate proc_macro; use proc_macro::{TokenStream, TokenTree, Group, Delimiter}; #[proc_macro_attribute] pub fn first(_attr: TokenStream, item: TokenStream) -> TokenStream { let tokens: TokenStream = "#[derive(Second)]".parse().unwrap(); let wrapped = TokenTree::Group(Group::new(Delimiter::None, item.into_iter().collect())); tokens.into_iter().chain(std::iter::once(wrapped)).collect() } #[proc_macro_derive(Second)] pub fn second(item: TokenStream) -> TokenStream { TokenStream::new() }