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    <p><strong>To the first question.</strong> <code>CComPtr::Release()</code> has the same effect as assigning a null pointer to the object. You can call <code>Release()</code> (or assign a null pointer) if for whatever reason you want to release the object <em>before</em> the pointer goes out of scope. For example:</p> <pre><code>CComPtr&lt;ISomeInterface&gt; pointer; HRESULT hr = firstProvider-&gt;GetObject( &amp;pointer ); if( SUCCEEDED( hr ) ) { //use the object pointer.Release(); } HRESULT hr = secondProvider-&gt;GetObject( &amp;pointer ); if( SUCCEEDED( hr ) ) { //use the object } </code></pre> <p>You see, when <code>GetObject()</code> obtains the pointer it overwrites the value already stored in <code>CComPtr</code>. If <code>CComPtr</code> stores a non-null pointer it will just be overwritten (shallow copy) and the object pointed to by the original pointer will be leaked. You don't need <code>Release()</code> before the first <code>GetObject()</code> - the pointer is null at that point. And you don't need either after the second <code>GetObject()</code> - the object will be relased once the pointer goes out of scope.</p> <p><strong>To the second question</strong>. Yes, you can return <code>CComPtr</code> but only if the caller also accepts it into <code>CComPtr</code>. The following code:</p> <pre><code>ISomeInterface* pointer = YourFunctionReturningCComPtr(); </code></pre> <p>will not take ownership of the object, so the object will be released and <code>pointer</code> will become dangling. That's undefined behavior.</p> <p><strong>To the tird question</strong> <code>CComPtr</code> is for ownership. Usually there's no point in passing <code>CComPtr</code> as an "in" parameter unless you know why exactly you do it.</p>
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    1. COThanks! 1.: I didn't know that. So that's why there is Release() in SetSite function(in the link in my question). I thought It would be smarter ;) So I should use Release when I'm using the same CComPtr more than just for one interface? And when I'm obtaining object by using '&' operator yes? I mean if I use '=' and get reference from other CComPtr do I have to call Release to?
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    2. CO3.: Do I get it right?: When I pass a CComPTR to function that accepts CComPtr the reference counter is increased in functions and then decreased after returning from function. Then program executes normally and do what's after the call. That's why I don't need to pass it as a CComPtr but can use normal pure pointer because nothing changes. But what if function is called asynchronously and after invoking function you release pointer (for example by going out of scope)?
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    3. CO@CichyK24: If you assign another pointer with = the previously pointed to object will be released - you can actually step into ATL code and see how it works. To Q3 - if a function is called asynchronously you have to store a `CComPtr` somewhere holding the object alive for at least the duration of that function - it can be the function parameter or some other variable.
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