OpOverloadWithGenerics.pas

type
  TObjectHelper = class helper for TObject
  public
    class function &&op_LogicalOr<T: class>(A, B: T): T; static;
  end;

class function TObjectHelper.&&op_LogicalOr<T>(A, B: T): T;
begin
  if A <> nil then
    Result := A
  else
    Result := B;
end;

procedure Test;
var
  sl1, sl2, sl3: TStringList;
begin
  sl1 := nil;
  sl2 := TStringList.Create;
  sl3 := sl1 or sl2; // -> sl3 = sl2
end;