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struct MYPROJECT_NotificationVariant
{
  MYPROJECT_TYPE_Notify  eNotify;

  union
  {
                  MYPROJECT_STRUCT_SOMESTRUCT_1      _s1;
                  MYPROJECT_STRUCT_SOMESTRUCT_2      _s2;
                  MYPROJECT_STRUCT_SOMESTRUCT_3      _s3;
                  // ....					

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type
  TMyProjectNotifyVariant = packed record
    eNotify : TMyProject_TYPE_Notify;
    // und jetzt? - 'case xx of' ?
end;					

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type
  MYPROJECT_STRUCT_SOMESTRUCT_1 = byte;
  MYPROJECT_STRUCT_SOMESTRUCT_2 = word;
  MYPROJECT_STRUCT_SOMESTRUCT_3 = integer;
  TMYPROJECT_NotificationVariant =
  record
    case integer of
      0 : (_s1: MYPROJECT_STRUCT_SOMESTRUCT_1);
      1 : (_s2: MYPROJECT_STRUCT_SOMESTRUCT_2);
      2 : (_s3: MYPROJECT_STRUCT_SOMESTRUCT_3);
    // vorsicht! in diesem fall ist es ganz richtig das den case das "end" fehlt
  end;					

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TVariantRec = packed record case byte of
  0: (SomeIntVar: Integer);
  1: (SomeDWORDVar: DWORD);
end;

TLargerRec = paced record
  ABool: Boolean;
  VariantPart: TVariantRec;
  SomethingElse: Integer;
end;