std::line!

macro_rules! line {
    () => { ... };
}

A macro which expands to the line number on which it was invoked.

The expanded expression has type u32, and the returned line is not the invocation of the line!() macro itself, but rather the first macro invocation leading up to the invocation of the line!() macro.

Examples

fn main() { let current_line = line!(); println!("defined on line: {}", current_line); }

let current_line = line!();
println!("defined on line: {}", current_line);