title: Idiomatic way to convert ascii array to string in Rust
body: <p>From a byte array, I want to convert a slice to a string using the ASCII-encoding.
  The solution</p>
  <pre class="lang-rust prettyprint-override"><code>fn main() {
      let buffer: [u8; 9] = [255, 255, 255, 255, 77, 80, 81, 82, 83];
      let s = String::from_iter(buffer[5..9].iter().map(|v| { *v as char }));
      println!(&quot;{}&quot;, s);
      assert_eq!(&quot;PQRS&quot;, s);
  }
  </code></pre>
  <p>does not seem to be idiomatic, and has a smell of poor performance.
  Can we do better?
  Without external crates?</p>