title: C++ Tokenizer using istream_iterator
body: <p>This is a question regarding an answer found <a href="https://stackoverflow.com/a/237280/1061193">here</a>.</p>
  
  <p>The following tokenizes a <code>string</code>:</p>
  
  <pre><code>string sentence = "And I feel fine...";
  istringstream iss(sentence);
  vector&lt;string&gt; tokens{istream_iterator&lt;string&gt;{iss},
                        istream_iterator&lt;string&gt;{}};
  </code></pre>
  
  <p>What does the last line mean? What is the purpose of the <code>{}</code>.</p>