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Use operator overloading for classes with non-ARC compiler
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program Project1; | |
{$APPTYPE CONSOLE} | |
uses | |
System.SysUtils, System.Classes, System.Types, Vcl.Dialogs; | |
type | |
TStringListEx = class(TStringList) | |
public | |
// class operator In(const A: string; B: TStringListEx): Boolean; | |
class function &&op_In(const A: string; B: TStringListEx): Boolean; static; | |
end; | |
TPointHelper = record helper for TPoint // Possible in class helper! | |
public | |
// class operator Equal(const A: TPoint; const B: string) : Boolean; | |
class function &&op_Equality(const A: TPoint; const B: string): Boolean; static; | |
end; | |
class function TStringListEx.&&op_In(const A: string; B: TStringListEx): Boolean; | |
begin | |
Result := B.IndexOf(A) >= 0; | |
end; | |
class function TPointHelper.&&op_Equality(const A: TPoint; const B: string): Boolean; | |
begin | |
Result := Format('%d,%d', [A.X, A.Y]) = B; | |
end; | |
var | |
sl: TStringListEx; | |
pt: TPoint; | |
ret: Boolean; | |
begin | |
sl := TStringListEx.Create; | |
sl.Add('AAA'); | |
sl.Add('BBB'); | |
ret := 'AAA' in sl; | |
Writeln(BoolToStr(ret, True)); // -> 'True' | |
pt := Point(123, 456); | |
ret := pt = '123,456'; | |
Writeln(BoolToStr(ret, True)); // -> 'True' | |
Readln; | |
end. |
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