vendor/csv/examples/tutorial-write-serde-01.rs

   1 use std::{error::Error, io, process};
   2
   3 fn run() -> Result<(), Box<dyn Error>> {
   4     let mut wtr = csv::Writer::from_writer(io::stdout());
   5
   6     // We still need to write headers manually.
   7     wtr.write_record(&[
   8         "City",
   9         "State",
  10         "Population",
  11         "Latitude",
  12         "Longitude",
  13     ])?;
  14
  15     // But now we can write records by providing a normal Rust value.
  16     //
  17     // Note that the odd `None::<u64>` syntax is required because `None` on
  18     // its own doesn't have a concrete type, but Serde needs a concrete type
  19     // in order to serialize it. That is, `None` has type `Option<T>` but
  20     // `None::<u64>` has type `Option<u64>`.
  21     wtr.serialize((
  22         "Davidsons Landing",
  23         "AK",
  24         None::<u64>,
  25         65.2419444,
  26         -165.2716667,
  27     ))?;
  28     wtr.serialize(("Kenai", "AK", Some(7610), 60.5544444, -151.2583333))?;
  29     wtr.serialize(("Oakman", "AL", None::<u64>, 33.7133333, -87.3886111))?;
  30
  31     wtr.flush()?;
  32     Ok(())
  33 }
  34
  35 fn main() {
  36     if let Err(err) = run() {
  37         println!("{}", err);
  38         process::exit(1);
  39     }
  40 }