Function base64_url::encode_to_string

pub fn encode_to_string<'a, T: ?Sized + AsRef<[u8]>>(
    input: &T, 
    output: &'a mut String
) -> &'a str

Encode data to a Base64-URL string and directly store to a mutable String reference by concatenating them and return the slice of the Base64-URL string. It is usually for generating a URL.