title: Does C++ have existing method to check if an object is a derived-typed object?
body: <p>Does C++ have existing method to check if an object is a derived-typed object? For example,</p>
  
  <pre><code>class A
  {};
  
  class B : public A
  {};
  
  A* p;
  </code></pre>
  
  <p>And check if <code>p</code> points to <code>B</code>.</p>