WTF abstract is?

[Zhouxuan]

On Friday, 4 October 2013 at 06:10:30 UTC, deadalnix wrote:
> On Friday, 4 October 2013 at 05:07:53 UTC, Zhouxuan wrote:
>> ////////////////////////////////////////////////////////////
>> //case 1
>>
>> class A
>> {
>>    abstract void foo();
>> }
>>
>> class B : A
>> {
>>    static if( __traits(isAbstractClass, typeof(this) ))
>
> this is invalid here. Not sure what you try to achieve via this 
> static if.

I want to define some variables in non-abstract class.