AsyncOperationWithProgressCompletedHandler: error "incomplete type is not allowed"

Question

I was trying to compile the "Building your first Windows Metro style app" example at http://msdn.microsoft.com/en-us/library/windows/apps/br211380.aspx.

I have:

// ...
using namespace Platform;
using namespace Windows::Foundation;
using namespace Windows::Web::Syndication;
// ...

void MainPage::GetFeedAsync(String^ feedUriString)
{	
	// ...
	auto feedOperation = client->RetrieveFeedAsync(ref new Uri(feedUriString));
	feedOperation->Completed = ref new AsyncOperationWithProgressCompletedHandler<SyndicationFeed^,RetrievalProgress>(this, &MainPage::Feed_Done); // error!
	// ...	
}

void MainPage::Feed_Done(IAsyncOperationWithProgress<SyndicationFeed^,RetrievalProgress>^ op) {
	// ...
}

I get:

compile error "incomplete type is not allowed" with curly line under AsyncOperationWithProgressCompletedHandler and

compile error "expected a ')'" with curly line under the comma after 'this'.

 

Thx in advance.