14.1.4. 编码和解码 base64

使用 encode 将字节切片编码为 base64 字符串，对 base64 字符串解码使用 decode。

use error_chain::error_chain;

use std::str;
use base64::{encode, decode};

error_chain! {
    foreign_links {
        Base64(base64::DecodeError);
        Utf8Error(str::Utf8Error);
    }
}

fn main() -> Result<()> {
    let hello = b"hello rustaceans";
    let encoded = encode(hello);
    let decoded = decode(&encoded)?;

    println!("origin: {}", str::from_utf8(hello)?);
    println!("base64 encoded: {}", encoded);
    println!("back to origin: {}", str::from_utf8(&decoded)?);

    Ok(())
}