use percent_encoding; // 1.0.1
use percent_encoding::{percent_decode, percent_encode, DEFAULT_ENCODE_SET};
use std::borrow::Cow;

fn main() {
    // has invalid sequence of bytes (non-utf8)
    let trash_file = b"tras \xff\xee\xef\xced d h.txt";
    let percent_encoded = percent_encode(trash_file, DEFAULT_ENCODE_SET).to_string();
    println!("encoding: {}", &percent_encoded);
    println!("expected: {}", "tras%20%FF%EE%EF%CEd%20d%20h.txt");
    // encoding is right

    // How to get back the original bytes though?
    let percent_decoded = percent_decode(percent_encoded.as_bytes()).if_any()
        .map_or(Cow::Borrowed(percent_encoded.as_bytes()), Cow::Owned);
    assert_eq!(trash_file, &*percent_decoded);
}