title: Implicit instantiation of undefined template 'std::__1::array<int, 3>'
body: <p>I copy and pasted this exact code, found <a href="http://en.cppreference.com/w/cpp/container/array">here</a> into my IDE, and got an error, I don't understand why it's happening and would like to learn why.</p>
  
  <pre><code>std::array&lt;int, 3&gt; a2 = {1, 2, 3}; // except after =
  </code></pre>