Declaration of template

We are migrating our projects from vs2005 to VS2015 .In one of the project we are using below template declaration Hide   Copy Code template 

In 2005,it is building successfully but in vs2015 getting below error.  Hide   Copy Code 'WindowClass': illegal type for non-type template parameter 'WindowClass'

I am not sure about the use of dllexport inside a template . Anyone know why it is useful and why it is not working in vs2015?