delphi - Is this the correct way to return an empty generic value? -

i have hashtable , need way return not_found result.

type   tcell<t> = record   .....     property key: cardinal read fkey write fkey;     property data: t read fdata write fdata;   end;    thashtable<t> = class(tenumerable<t>)   private     fcells: array of tcell<t>;     fempty: t;   ...     constructor create(initialsize: cardinal); overload;     function lookup(key: cardinal): t;   ...   end;  constructor thashtable<t>.create(initialsize: cardinal); begin   inherited create;   // initialize regular cells   farraysize:= initialsize;   assert((farraysize , (farraysize - 1)) = 0); // must power of 2   setlength(fcells, farraysize);    fillchar(fempty, sizeof(fempty), #0);  //superfluous know, there                                          //demonstrate point.  end; 

given above structure, how return not found result?
if had pointers, return nil pointer t.
pointers generic types not allowed.

so i've come solution below:

function thashtable<t>.lookup(key: cardinal): t; var   cell: nativeuint; begin   if (key <> 0) begin     // check regular cells     cell:= first_cell(integerhash(key));     while (true) begin       if (fcells[cell].key = key) exit(fcells[cell].data);       if not (fcells[cell].key = 0) exit(fempty);  <<-- correct?       cell:= circular_next(cell);     end;   end else begin     result:= fempty;   <<--- can return empty generic this?   end; end; 

can return zero-initialized generic mean no result?

or run problems structured types of (classes/records/variants/strings etc).

note understand ambiguity when t integer. 0 might valid value , indistinguishable not_found.
i'm not worried results.

what you're looking default(t), return 0 value type t.