Untyped `Pos`

{
  @params:
    Haystack:  Ref to the haystack pos.
    Needle:    The needle.
    HaystkLen: Number of elements in haystack
    ElmntSize: Size of each element.
}
function Find(var Haystack,Needle; HaystkLen:UInt32; ElmntSize:SizeInt): Int32;
var
  i,hi,lo,ss:Int32;
  PBData,PBSeek,P,Q:PChar;
begin
  PBData := PChar(@Haystack);
  PBSeek := PChar(@Needle);
  P := PBData[0];
  Q := PBSeek[0];
  lo := Int32(PBData[0]);
  hi := Int32(PBData[HaystkLen*ElmntSize] - ElmntSize);
  while hi > UInt32(P) do
  begin
    if (Q^ <> P^) then begin
      inc(p,ElmntSize);
      continue;
    end;
    if CompareMem(Q, P, ElmntSize) then
      Exit((UInt32(P)-lo) div ElmntSize);
    inc(p,ElmntSize);
  end;
  Exit(-1);
end;


var
  TIA: TIntegerArray;   ValI: Int32;
  TBA: TByteArray;      ValBt: Byte;
  TPA: TPointArray;     ValPT: TPoint;
begin
  //TIA
  TIA := [0,1,2,3,4,5,6,7,8,9];
  ValI := 5;

  //TBA
  TBA := [0,1,2,3,4,5,6,7,8,9];
  ValBt := 5;

  //TPA
  TPA := [[0,0],[1,1],[2,2],[3,3],[4,4],[5,5],[6,6],[7,7],[8,8],[9,9]];
  ValPt := Point(5,5);


  //---- Find index of value:
  WriteLn( Find(TIA[0], ValI,  Length(TIA), SizeOf(Int32))  );
  WriteLn( Find(TPA[0], ValPt, Length(TPA), SizeOf(TPoint)) );
  WriteLn( Find(TBA[0], ValBt, Length(TBA), SizeOf(Byte))   );
end.