Get superclasses at compile time

[Straivers via Digitalmars-d-learn]

On Tuesday, 5 January 2016 at 04:41:45 UTC, Rikki Cattermole 
wrote:
> On 05/01/16 5:37 PM, Straivers wrote:
>> Hello,
>>
>> I'm working on an event system, and I want to be able to check 
>> if an
>> event is a subclass of another event. How might I go about 
>> this? In
>> essence, I'm looking to compress this:
>>
>> static if (E == UserInputEvent || E == MouseEvent || E ==
>> MouseButtonEvent || E == MouseReleasedEvent)
>> {
>>      //MouseEvent => MouseButtonEvent => MouseReleasedEvent
>>      mreListeners[mrePtr] = listener;
>>      mrePtr++;
>> }
>>
>> into something like this:
>>
>> static if (isSuperclassOf!(MouseReleasedEvent, E))
>> {
>>      mreListeners[mrePtr] = listener;
>>      mrePtr++;
>> }
>>
>> Thank you for your time.
>>
>> -S
>
> is(E : UserInputEvent)

Okay, maybe I didn't write enough. I have multiple subtypes like:

static if (E == UserInputEvent || E == MouseEvent || E == 
MouseMovementEvent)
         { //MouseMovementEvent is a subclass of MouseEvent
             mmeListeners[mmePtr] = listener;
             mmePtr++;
         }
         static if (E == UserInputEvent || E == MouseEvent || E == 
MouseButtonEvent || E == MouseReleasedEvent)
         { //MouseEvent => MouseButtonEvent => MouseReleasedEvent
             mreListeners[mrePtr] = listener;
             mrePtr++;
         }
         static if (E == UserInputEvent || E == MouseEvent || E == 
MouseButtonEvent || E == MousePressedEvent)
         { //MouseEvent => MouseButtonEvent => MousePressedEvent
             mpeListeners[mpePtr] = listener;
             mpePtr++;
         }

and I want to differentiate between them so that a UserInputEvent 
will cause all three blocks to be compiled, but a 
MouseMovementEvent will only cause the first block to be 
compiled. Sorry about that.