demo.rs

 let output_file = match matches.value_of("OUTPUT_FILE") {
        Some(name) => fasta::Writer::new(File::create(name).expect(format!("Failed to open output file ({})", name).as_str())),
        None => fasta::Writer::new(io::stdout())
    };


//
// error[E0308]: match arms have incompatible types
// --> src/main.rs:42:23
//    |
// 42 |       let output_file = match matches.value_of("OUTPUT_FILE") {
//    |  _______________________^
// 43 | |         Some(name) => fasta::Writer::new(File::create(name).expect(format!("Failed to open output file ({})", name).as_str())),
// 44 | |         None => fasta::Writer::new(io::stdout())
//    | |                 -------------------------------- match arm with an incompatible type
// 45 | |     };
//    | |_____^ expected struct `std::fs::File`, found struct `std::io::Stdout`
//    |
//   = note: expected type `bio::io::fasta::Writer<std::fs::File>`
//              found type `bio::io::fasta::Writer<std::io::Stdout>`
//