title: How can I copy from a ReadOnlySpan<T> to an Array<T>?
body: <p>My class has a property <code>public byte[] Location{get;} = new byte[30];</code></p>
  <p>I want to be able to fill it from a <code>ReadOnlySpan&lt;byte&gt;</code> but I cannot find any API methods allowing this.</p>
  <p>The closest I've found is:</p>
  <pre><code>var array = span.Slice(0,30).ToArray();
  Array.Copy(array, Locations, 30);
  </code></pre>
  <p>But having to create a new array just to copy from it seems really ugly... one array creation and 2 copies are involved. I could make the property settable but it's not really the intended design.</p>
  <p>Am i missing some obvious method?</p>