fn valid_date(s: String) -> Result<(), String> {
    DateTime::parse_from_rfc3339(s.as_str())
        .map(|_| ())
        .map_err(|e| e.description().to_owned())
}
/// a clap validator for rfc3339 dates
a clap validator for rfc3339 dates
a clap validator for rfc3339 dates
fn valid_date(s: String) -> Result<(), String> {
    DateTime::parse_from_rfc3339(s.as_str())
        .map(|_| ())
        .map_err(|e| e.description().to_owned())
}
fn valid_date ( s : String ) -> Result < ( ) , String > { DateTime :: parse_from_rfc3339 ( s . as_str ( ) ) . map ( | _ | ( ) ) . map_err ( | e | e . description ( ) . to_owned ( ) ) }
a clap validator for rfc3339 dates
a clap validator for rfc3339 dates
s
String
s
String