[Bug c++/13088] New: templatizing outer class hides specialization of inner template class

[Bug c++/13088] New: templatizing outer class hides specialization of inner template class

[cppljevans at cox-internet dot com]

The specialization of nested template class is not found if
the outer class is also a template class.

-- 
           Summary: templatizing outer class hides specialization of inner
                    template class
           Product: gcc
           Version: 3.3.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: cppljevans at cox-internet dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2003-11-17 18:36 -------
We need a full testcase, can you provide one?

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |WAITING


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[cppljevans at cox-internet dot com]

------- Additional Comments From cppljevans at cox-internet dot com  2003-11-17 18:44 -------
Subject: Re:  templatizing outer class hides specialization
 of inner template class

On 11/17/2003 12:36 PM, pinskia at gcc dot gnu dot org wrote:

>------- Additional Comments From pinskia at gcc dot gnu dot org  2003-11-17 18:36 -------
>We need a full testcase, can you provide one?
>
>  
>
Just did.  Didn't include the .ii because it was too large.




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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2003-11-17 22:00 -------
You boost guys really have ways to write totally incomprehensible
testcases...

Anyway, the claim is justified, I guess. In essence, this boils down to
------------------
#include <iostream>

template <typename> struct S {
    template <typename> struct Type {};
};

template <typename> struct X {
    template <typename> struct Local;

};

template <typename U>
template <typename>
struct X<U>::Local {
    static void id() { std::cout << "primary\n" ;}
};

template <typename U>
template <typename T>
struct X<U>::Local<typename S<U>::template Type<T> > {
    static void id() { std::cout << "specialized\n" ;}
};


int main() {
  X<int>::Local<S<int>::Type<int> >::id();
}
-------------------------------

For this, we get

g/x> /home/bangerth/bin/gcc-3.3.2/bin/c++ x.cc ; ./a.out
primary

The same holds for every other gcc version that doesn't ICE outright. On
the other hand, icc for example prints "specialized". I guess it's wrong
that we don't match the partial specialization of X::Local.

W.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|WAITING                     |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2003-11-17 22:00:47
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[falk at debian dot org]

------- Additional Comments From falk at debian dot org  2003-11-17 22:05 -------
Just as a random factoid, the Compaq compiler thinks:

cxx: Error: test.cc, line 20: a partial specialization of a member class
          template must be declared in the class of which it is a member
struct X<U>::Local<typename S<U>::template Type<T> > {
-------------^
cxx: Info: 1 error detected in the compilation of "test.cc".

I don't have enough C++-fu to know whether it is right.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[cppljevans at cox-internet dot com]

------- Additional Comments From cppljevans at cox-internet dot com  2003-11-18 00:28 -------
Subject: Re:  templatizing outer class hides specialization
 of inner template class

On 11/17/2003 04:05 PM, falk at debian dot org wrote:

>------- Additional Comments From falk at debian dot org  2003-11-17 22:05 -------
>Just as a random factoid, the Compaq compiler thinks:
>
>cxx: Error: test.cc, line 20: a partial specialization of a member class
>          template must be declared in the class of which it is a member
>struct X<U>::Local<typename S<U>::template Type<T> > {
>-------------^
>cxx: Info: 1 error detected in the compilation of "test.cc".
>
>I don't have enough C++-fu to know whether it is right
>  
>
I think Compaq is right :(  See 
http://www.comeaucomputing.com/iso/cwg_defects.html#44




-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[cppljevans at cox-internet dot com]

------- Additional Comments From cppljevans at cox-internet dot com  2003-12-03 15:10 -------
(In reply to comment #6)
> Subject: Re:  templatizing outer class hides specialization
>  of inner template class
> 
> On 11/17/2003 04:05 PM, falk at debian dot org wrote:
> 
> >------- Additional Comments From falk at debian dot org  2003-11-17 22:05 -------
[snip]
> I think Compaq is right :(  See 
> http://www.comeaucomputing.com/iso/cwg_defects.html#44
> 
Closer reading of the defect report changed my mind.  In particular, the line:

 Proposed resolution (04/01): In-class specializations of member templates are
not allowed.

Hence, Compaq must be wrong, unless there are different rules for partial
specializations.  Will have to check on that.

Furthermore, the examples in paragraph 17 of 14.7.3 show examples
of out-of-class specializations.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[cppljevans at cox-internet dot com]

------- Additional Comments From cppljevans at cox-internet dot com  2003-12-03 16:25 -------
(In reply to comment #9)
> (In reply to comment #6)
[snip]
> Hence, Compaq must be wrong, unless there are different rules for partial
> specializations.  Will have to check on that.
The exmample code in paragraph 6 of section 14.5.4 supports the above
conclusion, i.e. Compaq is wrong about partial specialization of member
class template having to be declared in the class of which it is a
member.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[cppljevans at cox-internet dot com]

------- Additional Comments From cppljevans at cox-internet dot com  2004-02-28 21:29 -------
John Spicer at Edg convinced me it wasn't a bug by citing
the standard 14.8.2.4p4.

Bug maybe should be changed to resolved or not valid.




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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[cppljevans at cox-internet dot com]

------- Additional Comments From cppljevans at cox-internet dot com  2004-03-04 17:34 -------
The latest attachment, nested_deduction.zip, compares intel and g++ output,
which differ.  I believe intel's is right; hence, there's still a bug
in g++.  The g++ dated 20040225 was used in the test shown in attachment.


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |REOPENED
         Resolution|INVALID                     |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[cppljevans at cox-internet dot com]

------- Additional Comments From cppljevans at cox-internet dot com  2004-03-05 14:38 -------
Although last test was on 3.4, the same error occurs in 3.3.  I've just entered
the same bug, #14447, for gcc-3.4.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[giovannibajo at libero dot it]

------- Additional Comments From giovannibajo at libero dot it  2004-03-05 14:42 -------
*** Bug 14447 has been marked as a duplicate of this bug. ***

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[pinskia at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
  BugsThisDependsOn|                            |15818


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-06-04 05:24 -------
I should note that the last attached testcase ICE on the compiler, I filed PR 15818 for that ICE.

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[lerdsuwa at gcc dot gnu dot org]

-- 
Bug 13088 depends on bug 15818, which changed state.

Bug 15818 Summary: ICE on wierd templates
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15818

           What    |Old Value                   |New Value
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
             Status|NEW                         |RESOLVED
         Resolution|                            |DUPLICATE

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[lerdsuwa at gcc dot gnu dot org]

------- Additional Comments From lerdsuwa at gcc dot gnu dot org  2004-07-19 16:11 -------
Will investigate.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |lerdsuwa at gcc dot gnu dot
                   |dot org                     |org
             Status|REOPENED                    |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[lerdsuwa at gcc dot gnu dot org]

------- Additional Comments From lerdsuwa at gcc dot gnu dot org  2004-07-19 16:29 -------
The testcase nested_deduction.cpp works now.

However the code in comment #4 still doesn't work
due to a flaw in template argument deduction.
We are deducing 'U' and 'T' together at the same time in

  template <typename U>
  template <typename T>
  struct X<U>::Local<typename S<U>::template Type<T> >

rather than first substituting 'U' with 'int' and then
deducing 'T'.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-08-16 18:52 -------
Still present on mainline... 

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2003-11-17 22:00:47         |2004-08-16 18:52:15
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-10-15 14:55 -------
See also PR 4882. 
W. 

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[lerdsuwa at gcc dot gnu dot org]

------- Additional Comments From lerdsuwa at gcc dot gnu dot org  2004-11-28 10:47 -------
Work postponed to GCC 4.1.  This bug is tricky to fix.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[lerdsuwa at gcc dot gnu dot org]

------- Comment #25 from lerdsuwa at gcc dot gnu dot org  2005-10-22 13:57 -------
Won't work on it for a long while.


-- 

lerdsuwa at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|lerdsuwa at gcc dot gnu dot |unassigned at gcc dot gnu
                   |org                         |dot org
             Status|ASSIGNED                    |NEW


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[twhitehe at uwo dot ca]

------- Comment #26 from twhitehe at uwo dot ca  2007-02-16 15:04 -------
There is actually two different bugs here.

The original bug is a (rather convoluted) duplicate of 4882.  It still remains
unresolved as of gcc-4.1.

The nested_deduction.zip source, which was submitted much later, demonstrated a
different problems.  Nested templates didn't match on template template
specializations.  A vastly simplified (over the nested_deductions code) example
is:

template<typename>
struct A {
  template<typename>
  struct B { };
};

template<typename>
struct C { };

template<template<typename> class c,typename t>
struct C<c<t> > {
  typedef int type;
};

int main(void) {
  C<A<void> >::type val0 = 0;
  C<A<void>::B<void> >::type val1 = 0;  // Dies here

  return val0+val1;
}

With earlier versions of gcc, this would give the error

Simplified.cpp:17: error: `type' is not a member of type `C<A<void>::B<void>
>',

with gcc 4.1 it now compiles fine.

I appear, however, to not have the power to change the status of this report,
so someone else will have to.


-- 

twhitehe at uwo dot ca changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |twhitehe at uwo dot ca


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

[Bug c++/13088] templatizing outer class hides specialization of inner template class

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13088

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
                 CC|gcc-bugs at gcc dot gnu.org        |
      Known to work|                            |4.8.0, 4.9.0
         Resolution|---                         |FIXED

--- Comment #27 from Paolo Carlini <paolo.carlini at oracle dot com> ---
It seems to me that lately everything is fine.