How do I define implicit conversion operators for mutually dependent records?

Question

I am using the operator overloading for records in Delphi 2006. (Please don\'t answer this question by telling me not to.)

I have two record types with the impli

Answer 1

You might be able to do this with record helpers.

Below is what I recently did to work around the impossibility of having a forward record record declaration.

It uses the record helper construct, which - like implicit type casts - have drawbacks too.
The most important one being that only the nearest record helper for a particular record type will apply.

type
  TIpv4Address = record
  strict private
    FAddress: TIpv4Quad;
    FMask: TIpv4Quad;
  private
    class function CreateInternal(const IP_ADDR_STRING: _IP_ADDR_STRING): TIpv4Address; static;
  public
    class function Create(const IP_ADDR_STRING: _IP_ADDR_STRING): TIpv4Address; static;
    class function Count(const IP_ADDR_STRING: _IP_ADDR_STRING): Integer; static;
    property Address: TIpv4Quad read FAddress;
    property Mask: TIpv4Quad read FMask;
  end;

  TIpv4AddressList = array of TIpv4Address;

  TIpv4AddressHelper = record helper for TIpv4Address
    class function CreateList(const IP_ADDR_STRING: _IP_ADDR_STRING): TIpv4AddressList; static;
  end;

You use it like this:

function TAdapterInfo.GetIpAddressList: TIpv4AddressList;
begin
  Result := TIpv4Address.CreateList(AdapterInfos.IP_ADAPTER_INFO[Index].IpAddressList);
end;

--jeroen