title: Error in nested template argument when compile c++ in unix
body: <p>I just wrote a cpp file in unix.
  I have bunches of codes that use nested template argument.
  For example:</p>
  
  <pre><code>void showAlb(map&lt;string, vector&lt;string&gt;&gt; mapArt, map&lt;string, vector&lt;string&gt;&gt; mapSong, vector&lt;string&gt; artists, int artnumb);
  </code></pre>
  
  <p>However I always got error
  ` </p>
  
  <blockquote>
    <p>error: ?>?should be ? >?within a nested template argument list</p>
  </blockquote>
  
  <p>`</p>
  
  <pre><code> void showAlb(map&lt;string, vector&lt;string&gt;&gt; mapArt, map&lt;string, vector&lt;string&gt;&gt; mapSong, vector&lt;string&gt; artists, int artnumb);`
                                     ^
  </code></pre>
  
  <p>How can I fix it?</p>