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use std::{error::Error, io, process};
fn run() -> Result<(), Box<dyn 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);
}
}