is(this : myClass)

[Patrick]

On Friday, 20 October 2017 at 21:42:32 UTC, Jonathan M Davis 
wrote:
> On Friday, October 20, 2017 21:32:48 Patrick via 
> Digitalmars-d-learn wrote:
>> The compiler seems to reject the following code in a class 
>> method:
>>
>> bool test = is(this : myClass);
>>
>> Could some please explain this?
>
> "this" is not a type. is(T : U) is true if T is implicitly 
> convertible to U.
> T and U must both be types. So, you need to use the types of 
> this and
> myClass, even if that's just is(typeof(this) : typeof(myClass)) 
> rather than
> explicitly using their types.
>
> - Jonathan M Davis

Thank you.

Due to the very specific nature of the 'is' operator, why 
wouldn't the compiler know to implicitly query the class types? 
Why must it be explicitly written, typeof(this)?

Patrick