CSV thingy from http://words.steveklabnik.com/the-expressive-c-17-coding-challenge-in-rust-revisited with quicli

Cargo.toml

[package]
name = "steves-csv-thingy"
version = "0.1.0"
authors = ["Pascal Hertleif <killercup@gmail.com>"]

[[bin]]
name = "quicsv"
path = "main.rs"

[dependencies]
quicli = "0.2.0"
csv = "1.0.0-beta.5"
serde = "1.0.27"

main.rs

#[macro_use] extern crate quicli;
extern crate csv;

use quicli::prelude::*;

#[derive(Debug, Serialize, Deserialize)]
struct Record<'a> {
    name: &'a str,
    surname: &'a str,
    city: &'a str,
    country: &'a str,
}

#[derive(StructOpt, Debug)]
struct Opt {
    filename: String,
    column_name: String,
    replacement: String,
    output_filename: String,
}

main!(|args: Opt| {
    use std::fs::File;

    let input = File::open(&args.filename)?;
    let output = File::create(&args.output_filename)?;

    let mut rdr = csv::Reader::from_reader(input);
    let mut wtr = csv::Writer::from_writer(output);

    let mut raw_record = csv::StringRecord::new();
    let headers = rdr.headers()?.clone();

    while rdr.read_record(&mut raw_record)? {
        let mut record: Record = raw_record.deserialize(Some(&headers))?;

        match &*args.column_name {
            "name" => record.name = &args.replacement,
            "surname" => record.surname = &args.replacement,
            "city" => record.city = &args.replacement,
            "country" => record.country = &args.replacement,
            _ => panic!("incorrect column name"),
        }

        wtr.serialize(record)?;
    }

    wtr.flush()?;
});