title: Simplest way to check for basic latin letter (A-Z)
body: <p>Maybe I'm missing something obvious, but is there a simpler way to check if a character is a basic latin letter (a-z) other than converting to a string and using Regex?: For example:</p>
  
  <pre><code>public static bool IsBasicLetter(Char c) {
      return Regex.IsMatch(c.ToString(), "[a-z]", RegexOptions.IgnoreCase);
  }
  </code></pre>
  
  <p>Char.IsLetter matches hundreds of letter characters from many alphabets. I could directly check the code points, but that feels sketchy:</p>
  
  <pre><code>public static bool IsBasicLetter(Char c) {
      int cInt = c;
      return !(cInt &lt; 65 || cInt &gt; 122 || (cInt &gt; 90 &amp; cInt &lt; 97));
  }
  </code></pre>