title: Checking a string contains only ASCII characters
body: <p>Does Go have any method or there is a suggestion how to check if a string contains only ASCII characters? What is the right way to do it?</p>
  
  <p>From my research, one of the solution is to check whatever there is any char greater than 127.</p>
  
  <pre><code>func isASCII(s string) bool {
      for _, c := range s {
          if c &gt; unicode.MaxASCII {
              return false
          }
      }
  
      return true
  }
  </code></pre>