//@ aux-build:format-string-proc-macro.rs #[macro_use] extern crate format_string_proc_macro; macro_rules! identity_mbe { ($tt:tt) => { $tt }; } fn main() { let a = 0; format!(identity_pm!("{a}")); //~^ ERROR there is no argument named `a` format!(identity_mbe!("{a}")); //~^ ERROR there is no argument named `a` format!(concat!("{a}")); //~^ ERROR there is no argument named `a` }