TFPGMap

TFPGMap is part of the FGL (Free Generics Library).

Example

Here is an example provided by forum user Remy Lebeau:

uses
  ..., fgl;
 
var
  Dict: TFPGMap<string, integer>;
  Value: Integer;
begin
  Dict := TFPGMap<string, integer>.Create;
  try
    Dict.Add('VarName', 99);
    ...
    Value := Dict['VarName'];
    ...
  finally
    Dict.Free;
  end;
end;

IndexOfData

By default TFPGMap<> does not provide a comparison for the Data type. So method IndexOfData will not find anything. You need to provide it by assigning the OnDataCompare event:

uses
  StrUtils, fgl;

{$R *.lfm}

type
  TMyTest = specialize TFPGMap<PtrInt, String>;
...
  public
    property MyTest: TMyTest read FMyTest write SetMyTest;
  end;
...
 
function CompareStringFunc(const aData1, aData2: String): Integer;
begin
  Result := AnsiCompareStr(aData1, aData2);
end;
 
procedure TForm1.FormCreate(Sender: TObject);
var
  i: PtrInt = 0;
begin
  FMyTest:= TMyTest.Create;
  FMyTest.OnDataCompare := @CompareStringFunc;

See also

• https://www.freepascal.org/docs-html/current/rtl/fgl/tfpgmap.html