cascade operator or nearest equivalent

[Daniel Davidson]

Is there any way to simulate the cascade operator (..) of Dart in 
D? This operator makes fluid initialization simple.

I am using Dart for code generation but would like to consider D 
if I can find a convenient replacement for the following 
declarative style:

    var dateRange = struct('date_range')
      ..doc = 'Basic pair of start and end dates'
      ..unitTest = true
      ..publicSection = true
      ..members = [
        member('start_date')
        ..type = 'Date',
        member('end_date')
        ..type = 'Date',
      ];

So struct is a function that returns an instance of Struct.

    class Struct extends Decls {
      ...
      /// Documentation for this D struct
      String doc;
      /// List of members of this class
      List<Member> members = [];
      bool unitTest = false;
      ...
    }

..doc = ... assigns to the Struct.doc field and returns the 
original Struct instance so that ..unitTest = true can be applied 
to the original Struct instance, etc.

What is the best way to achieve simple declarative style for very 
large initialization objects?

Thanks,
Dan