Code:

{You do that simple by converting it to an integer, and then stores that:}

type

  pFontStyles = ^TFontStyles;

  pInteger = ^integer;

function FontStylesToInteger(const Value : TFontStyles): integer;

begin

  Result := pInteger(@Value)^;

end;

function IntegerToFontStyles(const Value : integer): TFontStyles;

begin

  Result := pFontStyles(@Value)^;

end;