constancy and template parameters in D2.009+

[guslay]

Janice Caron Wrote:

> RULE ONE: Head constancy is not considered significant in template
> instantiation.
> 
> Thus, (exactly as in D2.008), if "class A(T)" is instantiated with
> "int" and "const(int)", it will result in exactly one instantiation,
> with T being "int".
> 

I don't really understand the motivation behind the current behavior. Can someone explain why stripping away constness is not explicit?