Missing CodeLens references count in Visual Studio Community edition 2015 and 2017

Question

1. Is there a reason why the references count (code lens) is missing in Visual Studio Community edition?
2. Is is possible to enable it in the options?

Answer 1

This isn't a generic reference counting feature, it's just one of the features of CodeLens. CodeLens is only available in Visual Studio 2015 Pro and above. In Visual Studio 2013 it was a Ultimate-only feature.

UPDATE

As others have noted, installing SSDT or SSMS 2016 may enable CodeLens as well. That's because VS 2015 Community is Pro, with a different license and some missing extensions like CodeLens. As long as an extension's binaries and settings are installed, Community will activate the extension.

UPDATE 2019

"CodeLens has been a feature found only in Visual Studio Enterprise, but that will change in an upcoming preview of Visual Studio 2019, when it will also be available for the Community edition, likely in 2019" What's New in Visual Studio 2019