extern crate csv;
extern crate serde;

use serde::{Deserialize, Serialize};

#[derive(Debug, Serialize, Deserialize)]
struct Failed {
    field: usize,
}

fn main() -> Result<(), Box<std::error::Error>> {
    let data = "\
city,country,pop
Boston,United States,42695
Concord,United States,42695
";

    let mut rdr = csv::Reader::from_reader(data.as_bytes());
    for result in rdr.deserialize() {
        let record: Failed = match result {
            Ok(record) => record,
            Err(err) => {
                match *err.kind() {
                    csv::ErrorKind::Deserialize { pos: Some(ref pos), .. } => {
                        println!("line: {}", pos.line());
                    }
                    _ => {
                        println!("not a deserialize error");
                    }
                }
                continue;
            }
        };
        println!("{:?}", record);
    }
    Ok(())
}