title: sort vector by more than 1 field
body: <p>How do I sort the below code by name, age and score... all three fields</p>
  
  <pre><code> #include &lt;string&gt;
   #include &lt;vector&gt;
   #include &lt;algorithm&gt;
  
   struct student_t
   {
        std::string name;
        int age, score;
   };
  
   bool by_more_than_1_field( student_t const &amp;lhs, student_t const &amp;rhs )
   {
        // sort by name, age and score
   }
  
   int main()
   {
   std::vector&lt; student_t &gt; students;
   // populate students
  
   std::sort( students.begin(), students.end(), by_more_than_1_field );
   }
  </code></pre>