title: owner<T*> p syntax in cpp core guidelines
body: <p>In cpp core guidelines: <a href="http://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#r3-a-raw-pointer-a-t-is-non-owning" rel="noreferrer">Example of non owning raw pointer</a>
  I do not understand the following code:</p>
  
  <pre><code> template&lt;typename T&gt;
  class X2 {
      // ...
  public:
      owner&lt;T*&gt; p;  // OK: p is owning
      T* q;         // OK: q is not owning
  };
  </code></pre>
  
  <p>what is this syntax <code>owner&lt;T*&gt; p</code> ?</p>