title: vector of pair initialization
body: <p>Can someone please help me understand how this piece of code works?</p>
  
  <pre><code>Pair a[] = {{5, 29}, {39, 40}, {15, 28}, {27, 40}, {50, 90}};
  int n = sizeof(a)/sizeof(a[0]);
  vector&lt;Pair&gt; arr(a, a + n);
  </code></pre>
  
  <p>(Pair is a structure that has two integers a and b)</p>
  
  <p>From what I could tell, it places each pair in a separate array, but I've never seen this kind of declaration before.</p>