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extern crate csv;
use std::error::Error;
use std::io;
use std::process;
fn run() -> Result<(), Box<Error>> {
let mut wtr = csv::Writer::from_writer(io::stdout());
// We still need to write headers manually.
wtr.write_record(&["City", "State", "Population", "Latitude", "Longitude"])?;
// But now we can write records by providing a normal Rust value.
//
// Note that the odd `None::<u64>` syntax is required because `None` on
// its own doesn't have a concrete type, but Serde needs a concrete type
// in order to serialize it. That is, `None` has type `Option<T>` but
// `None::<u64>` has type `Option<u64>`.
wtr.serialize(("Davidsons Landing", "AK", None::<u64>, 65.2419444, -165.2716667))?;
wtr.serialize(("Kenai", "AK", Some(7610), 60.5544444, -151.2583333))?;
wtr.serialize(("Oakman", "AL", None::<u64>, 33.7133333, -87.3886111))?;
wtr.flush()?;
Ok(())
}
fn main() {
if let Err(err) = run() {
println!("{}", err);
process::exit(1);
}
}
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