Zuweisung für Enums überladen

[Panthrax]

Delphi-Quellcode:

program Project1;

{$APPTYPE CONSOLE}

uses
  SysUtils;

type
  TSomeEnum = (seOne, seTwo, seThree);

  TMyEnum = record
  strict private
    FValue: TSomeEnum;

    class function Translate(const Value: TSomeEnum): String; overload; static;
    class function Translate(const Value: String): TSomeEnum; overload; static;

  public
    class operator Implicit(const Value: String): TMyEnum;
    class operator Implicit(const Value: TMyEnum): String;
    class operator Implicit(const Value: TMyEnum): TSomeEnum;
    class operator Implicit(const Value: TSomeEnum): TMyEnum;
  end;

{ TMyEnum }

class operator TMyEnum.Implicit(const Value: TMyEnum): String;
begin
  Result := Translate(Value.FValue);
end;

class function TMyEnum.Translate(const Value: TSomeEnum): String;
begin
  case Value of
    seOne:
      Result := 'Eins';
    seTwo:
      Result := 'Zwei';
    seThree:
      Result := 'Drei';
  end;
end;

class operator TMyEnum.Implicit(const Value: String): TMyEnum;
begin
  Result.FValue := Translate(Value);
end;

class operator TMyEnum.Implicit(const Value: TSomeEnum): TMyEnum;
begin
  Result.FValue := Value;
end;

class operator TMyEnum.Implicit(const Value: TMyEnum): TSomeEnum;
begin
  Result := Value.FValue;
end;

class function TMyEnum.Translate(const Value: String): TSomeEnum;
begin
  if Value = 'Eins' then
    Result := seOne
  else
  if Value = 'Zwei' then
    Result := seTwo
  else
  if Value = 'Drei' then
    Result := seThree
  else
    raise Exception.Create('Ungültiger Wert.');
end;

var
  MyEnum: TMyEnum;
  SomeEnum: TSomeEnum;
begin
  try
    SomeEnum := seTwo;
    MyEnum := SomeEnum;
    WriteLn('MyEnum: ' + MyEnum);
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
  ReadLn;
end.

Code:

MyEnum: Zwei