Why type specialization is defined differently than is expression type specialization ?

[Roman D. Boiko]

On Wednesday, 27 June 2012 at 20:32:34 UTC, Roman D. Boiko wrote:
> On Wednesday, 27 June 2012 at 20:27:39 UTC, Steven 
> Schveighoffer wrote:
>> On Wed, 27 Jun 2012 16:16:53 -0400, Roman D. Boiko 
>> <rb at d-coding.com> wrote:
>>>> TypeSpecialization:
>>>>
>>>> Type struct union class interface enum function delegate 
>>>> super const immutable inout shared return
>>
>> This is only valid for is( Type == TypeSpecialization)
>
> No, unless the D specification is outdated.
>
> IsExpression:
> is ( Type )
> is ( Type : TypeSpecialization )
> is ( Type == TypeSpecialization )
> ...

Ups... Seems I implemented this incorrectly. Indeed, below there 
is a note:

TypeSpecialization is only allowed to be a Type.