[Bug c++/25950] [3.4/4.0/4.1 Regression] [DR 391] Reference binding and explicit copy constructors

["gdr at cs dot tamu dot edu" <gcc-bugzilla@gcc.gnu.org>]

------- Comment #7 from gdr at cs dot tamu dot edu  2006-01-25 02:38 -------
Subject: Re:  [3.4/4.0/4.1 Regression] [DR 391] Reference binding and explicit
copy constructors

"pinskia at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org> writes:

| (In reply to comment #4)
| > before you declare something as a regression, please make sure you do
| > understand the real issues.  When you don't fully understand, please
| > leave it alone and help somewhere else.  Thanks.
| 
| Well Marking things as regression is easy as it is just easy to test it on
| different versions of GCC which I did.

No, it is not that simple.
For example consider access checking (which this issue is about).  For
a long time, GCC has been known to be buggy on access checking,
therefore *wrongly* accepting codes it should reject (for example is
the PR you referenced.)  That was fixed by checking the accessibility
of the copy constructor even  when it is elided (as required by the
C++ standard). 

The C++ Working Paper has been slightly changed recently -- but not
the C++ standard -- to be somehow more permissisive in specific cases.
This PR is based on the hypothesis that the working paper stays as it
is on that point till we get the standard.
The proper categorization is that this is a request for enhancement. 

-- Gaby


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=25950