class scope virtual template functions

[Walter Bright]

BCS wrote:
> However in highly limited cases, this is not an issue.
> 1) the template members are enumerations (just build the whole set)
> 2) the function has no parameters (only one version can be built)
> 3) no general form of the template exists, only explicit specializations 
> (ditto enum)
> 4) class scope aliases of member templates are used. (instance the 
> template and stuff it in as a normal function)

True, but now you have the issue that minor, seemingly innocuous changes 
to a template function can have dramatic changes to its behavior. It's a 
lot easier to understand "template functions are not virtual" than 
"template functions are not virtual except in these rather complex 
scenarios."

If you need virtual behavior from a template function, the best way is 
to wrap a virtual function call within it.