// force-host // no-prefer-dynamic #![crate_type = "proc-macro"] extern crate proc_macro; use proc_macro::*; #[proc_macro] pub fn tokens(input: TokenStream) -> TokenStream { assert_nothing_joint(input); TokenStream::new() } #[proc_macro_attribute] pub fn nothing(_: TokenStream, input: TokenStream) -> TokenStream { assert_nothing_joint(input); TokenStream::new() } fn assert_nothing_joint(s: TokenStream) { for tt in s { match tt { TokenTree::Group(g) => assert_nothing_joint(g.stream()), TokenTree::Punct(p) => assert_eq!(p.spacing(), Spacing::Alone), _ => {} } } }