use std::{error::Error, io, process}; fn run() -> Result<(), Box> { let mut rdr = csv::Reader::from_reader(io::stdin()); { // We nest this call in its own scope because of lifetimes. let headers = rdr.headers()?; println!("{:?}", headers); } for result in rdr.records() { let record = result?; println!("{:?}", record); } // We can ask for the headers at any time. There's no need to nest this // call in its own scope because we never try to borrow the reader again. let headers = rdr.headers()?; println!("{:?}", headers); Ok(()) } fn main() { if let Err(err) = run() { println!("{}", err); process::exit(1); } }