Re: Get superclasses at compile time

[Rikki Cattermole via Digitalmars-d-learn]

On 05/01/16 5:50 PM, Straivers wrote:
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.

static if (is(E : UserInputEvent) || is(E : MouseEvent) || is(E : 
MouseButtonEvent) || is(E : MousePressedEvent)) {
        //....
}