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

[Roman D. Boiko]

On Wednesday, 27 June 2012 at 20:15:43 UTC, Roman D. Boiko wrote:
> On Wednesday, 27 June 2012 at 17:13:10 UTC, Timon Gehr wrote:
>> On 06/27/2012 03:56 PM, deadalnix wrote:
>>> All is in the title.
>>>
>>> I can do is(T : class) but not template(T : class) . Is this 
>>> intended or
>>> is it because it is ?
>>
>> You cannot do is(T : class).
>
> Why? According to grammar,
>
> IsExpression:
> is ( Type : TypeSpecialization )
>
> and
>
> TypeSpecialization:
>
> Type struct union class interface enum function delegate super 
> const immutable inout shared return

Sorry, I read like typeof(T):

is(typeof(T):class)