title: Why don't std::vector's elements need a default constructor?
body: <p>And how can I write my own array class to not need a default constructor for <em>its</em> elements? Right now, when I do the new [] to allocate space, I need a default constructor.</p>
  
  <p>std::vector does not.</p>
  
  <p>How do they do this magic?</p>