// The `format_args!` syntax extension issues errors before code expansion // has completed, but we still need a backtrace. // This test includes stripped-down versions of `print!` and `println!`, // because we can't otherwise verify the lines of the backtrace. fn print(_args: std::fmt::Arguments) {} macro_rules! myprint { ($($arg:tt)*) => (print(format_args!($($arg)*))); } macro_rules! myprintln { ($fmt:expr) => (myprint!(concat!($fmt, "\n"))); //~ ERROR no arguments were given } fn main() { myprintln!("{}"); }