extern crate proc_macro; use proc_macro::TokenStream; #[proc_macro] pub fn make_edition_macro(_input: TokenStream) -> TokenStream { "macro_rules! edition { ($_:expr) => { 2024 }; (const {}) => { 2021 }; } " .parse() .unwrap() } #[proc_macro] pub fn make_nested_edition_macro(_input: TokenStream) -> TokenStream { "macro_rules! make_inner { () => { macro_rules! edition_inner { ($_:expr) => { 2024 }; (const {}) => { 2021 }; } }; } " .parse() .unwrap() }