Methods chaining pattern

gistfile1.d

mixin template Identity()
{
  uint id = ID_UNKNOWN;
  string name = NAME_UNKNOWN;

  this() { }

  auto set_id(uint new_id) { this.id = new_id; return this; }
  auto set_name(string new_name) { this.name = new_name; return this; }
}

mixin template MarkerInfo() {
  mixin Identity;
  mixin Attributes;

  Chromosome chromosome = null;      /// Reference to Chromosome
  Position position = MARKER_POSITION_UNKNOWN; /// Marker position - content depends on map

  auto set_position(double new_position) { position = new_position; return this; }
  auto set_chromosome(Chromosome new_chromosome) { chromosome = new_chromosome; return this; }
}

class Marker {
  mixin MarkerInfo;
}

Marker m = (new Marker()).set_id(id).set_name(name).set_position(pos).set_chromosome(chrom);