__fastcall TDBISAMFieldDef(TDBISAMFieldDefs* Owner, const
      AnsiString Name, Db::TFieldType DataType, int Size, bool
      Required, const AnsiString DefaultValue, const AnsiString
      MinValue, const AnsiString MaxValue, const AnsiString
      Description, TFieldCharCase CharCase, Byte Compression, int
      FieldNo)

Use the New operator to create an instance of a TDBISAMFieldDef object using the constructor. However, you should never need to create an instance of the TDBISAMFieldDef object since one is automatically created when using the various methods of the TDBISAMFieldDefs object.