gcc/testsuite/gnat.dg/iter6.adb

   1 --  { dg-do compile }
   2
   3 with Ada.Iterator_Interfaces;
   4
   5 procedure Iter6 is
   6   package Pkg is
   7   type Item (<>) is limited private;
   8    private
   9
  10    type Cursor is null record;
  11
  12   function Constant_Reference (The_Item     : aliased Item;
  13                                Unused_Index : Cursor) return String
  14      is ("");
  15
  16   function Has_More (Data : Cursor) return Boolean is (False);
  17
  18   package List_Iterator_Interfaces is new Ada.Iterator_Interfaces
  19     (Cursor, Has_More);
  20
  21    function Iterate (The_Item : Item)
  22                     return List_Iterator_Interfaces.Forward_Iterator'class
  23      is (raise Program_Error);
  24
  25   type Item (Name_Length : Natural) is tagged limited record
  26      null;
  27   end record
  28   with
  29     Constant_Indexing => Constant_Reference,
  30     Default_Iterator  => Iterate,
  31     Iterator_Element  => String;
  32   end Pkg; use Pkg;
  33
  34   type Item_Ref is access Item;
  35   function F return Item_Ref is (null);
  36 begin
  37    for I of F.all loop --  { dg-error "cannot iterate over \"Item\"" }
  38      null;
  39    end loop;
  40 end;