//@aux-build:proc_macros.rs #![warn(clippy::useless_concat)] #![allow(clippy::print_literal)] extern crate proc_macros; use proc_macros::{external, with_span}; macro_rules! my_concat { ($fmt:literal $(, $e:expr)*) => { println!(concat!("ERROR: ", $fmt), $($e,)*); } } fn main() { let x = concat!(); //~ useless_concat let x = concat!('c'); //~ useless_concat let x = concat!('"'); //~ useless_concat let x = concat!(true); //~ useless_concat let x = concat!(1f32); //~ useless_concat let x = concat!(1.0000f32); //~ useless_concat let x = concat!(1_f32); //~ useless_concat let x = concat!(1_); //~ useless_concat let x = concat!(1.0000_f32); //~ useless_concat let x = concat!(1.0000_); //~ useless_concat let x = concat!("a\u{1f600}\n"); //~ useless_concat let x = concat!(r##"a"##); //~ useless_concat let x = concat!(1); //~ useless_concat println!("b: {}", concat!("a")); //~ useless_concat // Should not lint. let x = concat!("a", "b"); let local_i32 = 1; my_concat!("{}", local_i32); let x = concat!(file!(), "#L", line!()); external! { concat!(); } with_span! { span concat!(); } }