Re: GNAT - return by anonymous access

[anon@att.net]

A corrected version, that works!

Just made a few changes in the code.

  First GNAT does not like the "access Integer", define a 
Integer_Access type.

  Second, "limited" was remove because of the error message  
"cannot initialize entities of limited type".

  Third, I use an "Use" Statement in "test_driver.adb" instead of 
using of "test_package.".


-- Unit 1
package test_package is

   type Integer_Access is access all Integer ;

   type test_type (p_obj : Integer_Access) is private;

   function get return test_type;

private
   type test_type (p_obj : Integer_Access) is null record ;

end test_package;


-- Unit 2
package body test_package is

   function get return test_type is
   begin
      return test_type ' ( p_obj => new Integer'(42) );
   end get;

end test_package;


-- Unit 3
with test_package;
with Text_IO;
use test_package;

procedure test_driver is

   foo : test_type := test_package.get;

   -- Removed : '42' (expected)
   -- Present : '4409264'
   bar : Integer_Access := new Integer'(69);

begin

   Text_IO.Put_Line(foo.p_obj.all'img);

end test_driver;



In <784c67eb-a542-41b0-b23d-fca1234e56b2@n10g2000vbg.googlegroups.com>, Simon Belmont <sbelmont700@gmail.com> writes:
>
>This ostensibly simple program prints strange results, and i'm rapidly
>losing faith in the GNAT compiler (GNAT GPL 20110428).  If anyone with
>an alternative compiler can confirm or deny this output as spurious, I
>would be much obliged.  In short, when the declaration of 'bar' is
>commented out, the program behaves as i would expect (output is '42'),
>but when bar is present, the output is much different (output is
>'4409264').  Or, if my line of reasoning is mixed up and this is
>actually the appropriate behavior, I would be grateful for any
>explanation.
>
>Thank you again
>
>-sb
>
>-- Unit 1
>package test_package is
>   type test_type (p_obj : access Integer) is limited private;
>   function get return test_type;
>
>private
>   type test_type (p_obj : access Integer) is limited null record;
>
>end test_package;
>
>-- Unit 2
>package body test_package is
>
>   function get return test_type is
>   begin
>      return test_type'(p_obj => new Integer'(42));
>   end get;
>
>end test_package;
>
>-- Unit 3
>with test_package;
>with Text_IO;
>
>procedure test_driver is
>
>   foo : test_package.test_type := test_package.get;
>
>   -- Removed : '42' (expected)
>   -- Present : '4409264'
>   bar : access Integer := new Integer'(69);
>
>begin
>
>   Text_IO.Put_Line(foo.p_obj.all'img);
>
>end test_driver;