title: Tracking automatic variable lifetime?
body: <p>This may not be possible, but I figured I'd ask...</p>
  
  <p>Is there any way anyone can think of to track whether or not an automatic variable has been deleted without modifying the class of the variable itself? For example, consider this code:</p>
  
  <pre><code>const char* pStringBuffer;
  {
      std::string sString( "foo" );
      pStringBuffer = sString.c_str();
  }
  </code></pre>
  
  <p>Obviously, after the block, pStringBuffer is a dangling pointer which may or may not be valid. What I would like is a way to have a wrapper class which contains pStringBuffer (with a casting operator for const char*), but asserts that the variable it's referencing is still valid. By changing the type of the referenced variable I can certainly do it (boost shared_ptr/weak_ptr, for example), but I would like to be able to do it without imposing restrictions on the referenced type.</p>
  
  <p>Some thoughts:</p>
  
  <ul>
  <li>I'll probably need to change the assignment syntax to include the referenced variable (which is fine)</li>
  <li>I might be able to look at the stack pointer to detect if my wrapper class was allocated "later" than the referenced class, but this seems hacky and not standard (C++ doesn't define stack behavior). It could work, though.</li>
  </ul>
  
  <p>Thoughts / brilliant solutions?</p>