[Bug c++/23896] New: boost::tie() = std::pair doesn't compile

[Bug c++/23896] New: boost::tie() = std::pair doesn't compile

[Woebbeking at web dot de]

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Hi,   
   
with Debian's gcc (version 4.0.2 20050913 (prerelease) (Debian 4.0.1-7)) this 
doesn't compile anymore: 
 
    const std::pair<int, int> p(1, 2); 
 
    int i, j; 
    boost::tie(i, j) = p; 
 
It works with all older versions and MSVC 7.1. 
 
 
Cheers, 
André

-- 
           Summary: boost::tie() = std::pair doesn't compile
           Product: gcc
           Version: 4.0.2
            Status: UNCONFIRMED
          Severity: critical
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: Woebbeking at web dot de
                CC: doko at cs dot tu-berlin dot de,gcc-bugs at gcc dot gnu
                    dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23896

[Bug c++/23896] boost::tie() = std::pair doesn't compile

[Woebbeking at web dot de]

------- Additional Comments From Woebbeking at web dot de  2005-09-15 14:54 -------
Created an attachment (id=9735)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=9735&action=view)
example code, save-temps and compiler error message


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23896

[Bug c++/23896] [4.0 Regression] boost::tie() = std::pair doesn't compile

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-15 15:14 -------
Even after the fix for PR 23691, this still fails.  It worked with "4.0.2 20050826".

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |rejects-valid
      Known to fail|                            |4.0.2
      Known to work|                            |4.0.0
            Summary|boost::tie() = std::pair    |[4.0 Regression]
                   |doesn't compile             |boost::tie() = std::pair
                   |                            |doesn't compile
   Target Milestone|---                         |4.0.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23896

[Bug c++/23896] [4.0/4.1 Regression] boost::tie() = std::pair doesn't compile

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-15 15:15 -------
It also fails with "4.1.0 20050903".

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[4.0 Regression]            |[4.0/4.1 Regression]
                   |boost::tie() = std::pair    |boost::tie() = std::pair
                   |doesn't compile             |doesn't compile


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23896

[Bug c++/23896] [4.0/4.1 Regression] boost::tie() = std::pair doesn't compile

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-15 15:21 -------
Reducing.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23896

[Bug c++/23896] [4.0/4.1 Regression] boost::tie() = std::pair doesn't compile

[pinskia at gcc dot gnu dot org]

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23896

[Bug c++/23896] [4.0/4.1 Regression] boost::tie() = std::pair doesn't compile

[debian-gcc at lists dot debian dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|doko at cs dot tu-berlin dot|debian-gcc at lists dot
                   |de                          |debian dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23896

[Bug c++/23896] [4.0/4.1 Regression] boost::tie() = std::pair doesn't compile

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-09-15 16:22 -------
Reduced as far as I could do:
namespace boost{
  template <bool x> struct STATIC_ASSERTION_FAILURE {};
  struct null_type;
  template <class T0 = null_type, class T1 = null_type, class T2 = null_type> class tuple;
  template <class TT> struct cons {
    typedef TT tail_type;
  };
  template<class T> struct length {
    static const int value = 1 + length<typename T::tail_type>::value;
  };
  template<> struct length<null_type> {
    static const int value = 0;
  };
  namespace detail {
    template <class T0, class T1, class T2> struct map_tuple_to_cons {
      typedef cons<typename map_tuple_to_cons<T1, T2, null_type>::type > type;
    };
    template <> struct map_tuple_to_cons<null_type, null_type, null_type> {
      typedef null_type type;
    };
  }
  template <class T0, class T1, class T2>  struct tuple : detail::map_tuple_to_cons<T0, T1, T2>::type     
{
    tuple& operator=(int t1) {
      int t = sizeof(::boost::STATIC_ASSERTION_FAILURE< (bool)( length<tuple>::value == 2 ) >);
    }
  };
}
int main() {
  boost::tuple<int&, int&> a;
  a = 1;
}


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2005-09-15 16:22:23
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23896

[Bug c++/23896] [4.0/4.1 Regression] boost::tie() = std::pair doesn't compile

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2005-09-15 17:56 -------
This is what I come up with: 
------------------- 
template <int> struct X {}; 
 
template <typename T> struct length { 
    static const int value = 2; 
}; 
 
template <typename T> void foo () { 
  sizeof(X<length<T>::value>); 
} 
 
template void foo<int>(); 
----------------------------- 
 
g/x> /home/bangerth/bin/gcc-3.4*-pre/bin/c++ -c x.cc 
 
g/x> /home/bangerth/bin/gcc-4.0*-pre/bin/c++ -c x.cc 
x.cc: In function &#8216;void foo() [with T = int]&#8217;: 
x.cc:11:   instantiated from here 
x.cc:8: error: &#8216;length<int>::value&#8217; is not a valid template argument for type 
&#8216;int&#8217; because it is a non-constant expression 
 
g/x> /home/bangerth/bin/gcc-4.1*-pre/bin/c++ -c x.cc 
x.cc: In function &#8216;void foo() [with T = int]&#8217;: 
x.cc:11:   instantiated from here 
x.cc:8: error: &#8216;length<int>::value&#8217; is not a valid template argument for type 
&#8216;int&#8217; because it is a non-constant expression 
 
W. 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23896

[Bug c++/23896] [4.0/4.1 Regression] boost::tie() = std::pair doesn't compile

[mmitchel at gcc dot gnu dot org]

------- Additional Comments From mmitchel at gcc dot gnu dot org  2005-09-15 18:05 -------
Darn, I should never have fixed that original PR.  Silly me, trying to fix bugs.

Mine.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |mark at codesourcery dot com
                   |dot org                     |
             Status|NEW                         |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23896

[Bug c++/23896] [4.0/4.1 Regression] boost::tie() = std::pair doesn't compile

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-09-16 01:51 -------
Subject: Bug 23896

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	mmitchel@gcc.gnu.org	2005-09-16 01:50:26

Modified files:
	gcc/cp         : ChangeLog pt.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/g++.dg/template: static17.C 

Log message:
	PR c++/23896
	* pt.c (tsubst_aggr_type): Make sure skip_evaluation is false when
	processing template arguments.
	
	PR c++/23896
	* g++.dg/template/static17.C: New test.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&r1=1.4893&r2=1.4894
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/pt.c.diff?cvsroot=gcc&r1=1.1036&r2=1.1037
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.6068&r2=1.6069
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/template/static17.C.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23896

[Bug c++/23896] [4.0/4.1 Regression] boost::tie() = std::pair doesn't compile

[mmitchel at gcc dot gnu dot org]

------- Additional Comments From mmitchel at gcc dot gnu dot org  2005-09-16 01:54 -------
Fixed in 4.0.2.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23896

[Bug c++/23896] [4.0/4.1 Regression] boost::tie() = std::pair doesn't compile

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-09-16 01:54 -------
Subject: Bug 23896

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	gcc-4_0-branch
Changes by:	mmitchel@gcc.gnu.org	2005-09-16 01:53:43

Modified files:
	gcc/cp         : ChangeLog pt.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/g++.dg/template: static17.C 

Log message:
	PR c++/23896
	* pt.c (tsubst_aggr_type): Make sure skip_evaluation is false when
	processing template arguments.
	
	PR c++/23896
	* g++.dg/template/static17.C: New test.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.4648.2.104&r2=1.4648.2.105
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/pt.c.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.978.2.25&r2=1.978.2.26
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.5084.2.406&r2=1.5084.2.407
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/g++.dg/template/static17.C.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=NONE&r2=1.1.2.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23896

[Bug c++/23896] [4.0/4.1 Regression] boost::tie() = std::pair doesn't compile

[Woebbeking at web dot de]

------- Additional Comments From Woebbeking at web dot de  2005-09-17 08:30 -------
Wow, that was fast, thanks. I'll give it a try with the next Debian package. 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23896

[Bug c++/23896] [4.0/4.1 Regression] boost::tie() = std::pair doesn't compile

[Woebbeking at web dot de]

------- Additional Comments From Woebbeking at web dot de  2005-09-20 17:21 -------
Works for me. I hope VERIFIED is the same as CLOSED. 

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |VERIFIED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23896