CombinedProp

type
  TVariantArr = record
  private
    { implementation may differ }
    Data: Variant;
    Arr: TArray<Variant>;
    function GetItems(Index: Integer): Variant;
    procedure SetItems(Index: Integer; const Value: Variant);
  public
    class operator Implicit(A: TVariantArr): Variant; overload;
    class operator Implicit(A: Variant): TVariantArr; overload;
    property Items[Index: Integer]: Variant read GetItems write SetItems; default;
  end;

type
  ISome = interface
    function GetValue: TVariantArr; stdcall;
    procedure SetValue(const Value: TVariantArr); stdcall;
    property Value: TVariantArr read GetValue write SetValue;
  end;

function TVariantArr.GetItems(Index: Integer): Variant;
begin
  Result := Arr[Index];
end;

procedure TVariantArr.SetItems(Index: Integer; const Value: Variant);
begin
  Arr[Index] := Value;
end;

class operator TVariantArr.Implicit(A: TVariantArr): Variant;
begin
  Result := A.Data;
end;

class operator TVariantArr.Implicit(A: Variant): TVariantArr;
begin
  Result.Data := A;
end;