title: How to make lambda to extract all ids which belongs to year for example 1, 3, 5?
body: <p>I have vector of pairs  where first in pair is id and second is year of study 
  like </p>
  
  <pre><code>vector&lt; pairs&lt;uint64_t, int&gt;&gt; students;
  </code></pre>
  
  <p>How to make lambda to extract all ids which belongs to year for example 1, 3, 5 ?
  I solved this through iteration but I wonder if I can in c++11 make this simpler.</p>