identifier>std</span><span class=special>::</span><span class=identifier>string</span><span class=special>,&amp;</span><span class=identifier>phonebook_entry</span><span class=special>::</span><span class=identifier>phone_number</span><span class=special>&gt;</span>
    <span class=special>&gt;</span>
  <span class=special>&gt;</span>
<span class=special>&gt;</span> <span class=identifier>phonebook</span><span class=special>;</span>
</pre></blockquote>

<p>
See <a href="../examples.html#example7">example 7<