问Rust match语句需要逗号吗？

EN

for (index, character) in argv[1].chars().enumerate() {
match character {
    'a' | 'A' => {println!("{}: 'A'", index)}
    'e' | 'E' => {println!("{}: 'E'", index)}
    'i' | 'I' => {println!("{}: 'I'", index)}
    'o' | 'O' => {println!("{}: 'O'", index)}
    'u' | 'U' => {println!("{}: 'U'", index)}
     _        => {
                     let consonant: Vec<_> = character.to_uppercase().collect();
                     println!("{}: {:?} is not a vowel", index, consonant[0])
                 }
}