title: Regex Nested quantifier +
body: <p>I'm trying to replace <code>c++</code> with <code>&lt;b&gt;c++&lt;/b&gt;</code> in the following string:</p>
  
  <pre><code>"Select the projects entry and then select VC++ directories. Select show"
  </code></pre>
  
  <p>I want it to be  </p>
  
  <pre><code>"Select the projects entry and then select V&lt;b&gt;C++&lt;/b&gt; directories. Select show"
  </code></pre>
  
  <p>Im using this code : </p>
  
  <pre><code>string cssOld = Regex.Replace(
     "Select the projects entry and then select VC++ directories. Select show",
     "c++", "&lt;b&gt;${0}&lt;/b&gt;", RegexOptions.IgnoreCase);
  </code></pre>
  
  <p>I get the following error :<br>
  <code>System.ArgumentException: parsing "c++" - Nested quantifier +.</code></p>
  
  <p>This code works fine with other text(!c++). It seems like the + operator cause the Regex library to throw an exception. </p>