procedure TForm1.Button1Click(Sender: TObject);
var
l : TList<TPair<Integer,Integer>>;
p : TPair<Integer,Integer>;
begin
l := TList<TPair<Integer,Integer>>.Create;
Try
l.Add(TPair<Integer,Integer>.Create(1,1));
ShowMessage(Format('Item 0: Key = %d, Value = %d',[l[0].Key, l[0].Value]));
p := l[0];
p.Value := p.Value + 1;
l[0] := p;
ShowMessage(Format('Item 0: Key = %d, Value = %d',[l[0].Key, l[0].Value]));
Finally
l.Free;
End;
end;