Start with this valid code (playpen: https://is.gd/rPUytX): ``` rust fn main() { let x = ((1u8, 2), 3); println!("{}", x.0 .0); } ``` Click "format"; rustfmt will delete the space in `.0 .0`, but `.0.0` is a syntax error because the lexer interprets `0.0` as a float literal.