[Bug c++/13847] New: Additions to the changes.html file for 3.4.

[Bug c++/13847] New: Additions to the changes.html file for 3.4.

[mattyt-bugzilla at tpg dot com dot au]

Should add the following things to the 3.4 changes.html file.  Don't take my
word for it though, just going by what I'm told.  I don't know the specifics,
you'll need to get that from someone else.

Befriending and explicitly instantiating typedefs won't work anymore.

Need a "template <>" before templated static variable definitions.

The available function overloadings from a call in a template is determined at
definition time not instantiation time, except for Koenig lookup.

You need to put "class" on explicit instantiations of classes, ie no "template
A<B>;"

-- 
           Summary: Additions to the changes.html file for 3.4.
           Product: gcc
           Version: 3.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: mattyt-bugzilla at tpg dot com dot au
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13847

[Bug c++/13847] Additions to the changes.html file for 3.4.

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-01-24 15:47 -------
Confirmed, there are more to document in web site that has changed in 3.4.0 than there is there 
now, mostly because the new parser changed a large portion of this.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-01-24 15:47:33
               date|                            |
   Target Milestone|---                         |3.4.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13847

[Bug c++/13847] Additions to the changes.html file for 3.4.

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2004-01-25 16:50 -------
Befriending and explicitly instantiating typedefs won't work anymore.
***********************************************************************

Yes, this could use a changes.html entry. In standardese, GCC 3.4.0 enforces 
the standard clause in [basic.lookup.elab]/2 and /3, which talks about 
elaborated-type-specifiers (ETS): "If the name lookup finds a typedef-name, the 
elaborated-type-specifier is ill-formed."

An ETS is something of the form "class/struct/enum X;". ETS are mainly used for:

- forward declarations (not affected by recent changes).

- friend declarations. Given the bugfix above, GCC 3.4.0 doesn't allow anymore 
to befried a class through a typedef name:

class A;
typedef A B;
class C { 
  friend class B;   // ERROR! It used to work.
};

- Explicit instantiations. Again, you can't use typedef names anymore:

template <int> class A {};
typedef A<0> B;
template class B;   // ERROR! It used to work.

- As an additional note, ETS are also useful as a workaround if you have a both 
a type and a non-type entity bound to the same name.

struct A {};
int A;

void foo(void)
{
  A = 0;   // OK
  A a;     // ERROR, lookup finds "int A"
  struct A a;  // OK, lookup of ETS always finds "struct A".
}



Need a "template <>" before templated static variable definitions.
******************************************************************
This is already documented in changes.html.


The available function overloadings from a call in a template is determined at
definition time not instantiation time, except for Koenig lookup.
******************************************************************************
Ok. I would just say that, in templates, all (modulo bugs) unqualified names 
are now looked up in at definition time. This can be added as a rework of the 
third C++ entry in changes.html. An example code could be:

void foo(int);

template <int> struct A {
   static void bar(void){
       foo('a');
   }
};

void foo(char);

int main()
{
  A<0>::bar();    // Calls foo(int), used to call foo(char).
}


You need to put "class" on explicit instantiations of classes, ie no "template
A<B>;"
******************************************************************************
I didn't even know this was allowed before, must have been a GCC extension. OK, 
we can add a entry for this as well.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13847

[Bug c++/13847] Additions to the changes.html file for 3.4.

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2004-01-25 16:52 -------
Volker, are you willing to do the HTML job here?

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |reichelt at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13847

[Bug c++/13847] Additions to the changes.html file for 3.4.

[mattyt-bugzilla at tpg dot com dot au]

------- Additional Comments From mattyt-bugzilla at tpg dot com dot au  2004-01-26 14:34 -------
>> Need a "template <>" before templated static variable definitions.
> This is already documented in changes.html.

Template specialisations are documented, not static defines.

> Ok. I would just say that, in templates, all (modulo bugs) unqualified names 
> are now looked up in at definition time.

Well qualified ones are as well, and that's new ...

> I didn't even know this was allowed before, must have been a GCC extension.
> OK, we can add a entry for this as well.

Actually, I believe this was the norm.  See the C++ FAQ Lite for example, which
talks about explicit instantiations and uses no "class".

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13847

[Bug c++/13847] Additions to the changes.html file for 3.4.

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2004-02-05 14:53 -------
I forgot to say that, since I were at it, I also added an exhaustive example 
about the use of typename/template to disambiguate the parser, and a paragraph 
to introduce to the major changes users will face in 3.4.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13847

[Bug c++/13847] Additions to the changes.html file for 3.4.

[reichelt at gcc dot gnu dot org]

------- Additional Comments From reichelt at gcc dot gnu dot org  2004-02-05 20:04 -------
Giovanni,
the patch is valid XMTHL 1.0 (I just checked).
You don't need a ChangeLog entry for www-patches.
You just have to submit the patch to gcc-patches
(probably with [www-patch] in the title) and wait for approval.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13847

[Bug c++/13847] Additions to the changes.html file for 3.4.

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2004-02-08 20:46 -------
Current revision of the patch is here:
http://gcc.gnu.org/ml/gcc-patches/2004-02/msg00748.html



-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |patch


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13847

[Bug c++/13847] Additions to the changes.html file for 3.4.

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2004-02-09 14:06 -------
changes.html has been updated to reflect your suggestions. Thank you for your 
report!

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |FIXED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13847