title: Deferred member construction
body: <p>I have the following struct:</p>
  
  <pre><code>struct Logger::LoggerImpl {
      std::wofstream loggerStream;
  }
  </code></pre>
  
  <p>When I create a LoggerImpl, obviously a std::wofstream will be created implicitly (via the compiler's default constructor).</p>
  
  <p>My question is, is there a way to prevent (or defer) the construction of the wofstream, without using a pointer? Because I will create it later on with a given filename. </p>
  
  <p>I know that in this case it makes little difference, but I'm asking on a theoretical basis.</p>