Re: Alias variable from another class

[Ali via Digitalmars-d-learn]

I guess it's because you're accessing a member of _1 from inside 
a scope of _2 where nothing has been constructed yet? Someone 
more familiar with D would probably have a better answer on this 
part. I'm quite new :)

But a work around would be
class _2 {
          _1 instance;
        
          auto twelve() @property {
              return instance.i;
          }
        
          this() {
                  instance = new _1(12);
          }
  }