Capitalize a string in Rust

Rust doesn’t offer a convenient capitalization function on the string type, but there is to_uppercase on the char type. These can be strung together quite elegantly with pattern matching and iterators:

/// Capitalizes the first character in s.
pub fn capitalize(s: &str) -> String {
    let mut c = s.chars();
    match {
        None => String::new(),
        Some(f) => f.to_uppercase().collect::<String>() + c.as_str(),