Re: 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.