[Bug libstdc++/15523] New: Can't have vectors of vector::const_iterator

[Bug libstdc++/15523] New: Can't have vectors of vector::const_iterator

[bangerth at dealii dot org]

I definitely like the debug mode in libstdc++, but happened to fall over this: 
----------------- 
#include <vector> 
 
int main () 
{ 
  std::vector<std::vector<int>::const_iterator> x(2); 
} 
----------------- 
 
When compiled with -D_GLIBCXX_DEBUG -D_GLIBCXX_DEBUG_PEDANTIC, I got this: 
 
homes/csm2/bangerth/bin/gcc-3.4.0/bin/../lib/gcc/i686-pc-linux-gnu/3.4.0/../../../../include/c++/3.4.0/debug/safe_iterator.h:125: 
    error: attempt to copy-construct an iterator from a singular iterator. 
 
Objects involved in the operation: 
iterator "this" @ 0x0x8067ee0 { 
type = 
N11__gnu_debug14_Safe_iteratorIN9__gnu_cxx17__normal_iteratorIPKiN10__gnu_norm6vectorIiSaIiEEEEEN15__gnu_debug_def6vectorIiS7_EEEE 
(constant iterator); 
  state = singular; 
} 
iterator "other" @ 0x0xbfffdd40 { 
type = 
N11__gnu_debug14_Safe_iteratorIN9__gnu_cxx17__normal_iteratorIPKiN10__gnu_norm6vectorIiSaIiEEEEEN15__gnu_debug_def6vectorIiS7_EEEE 
(constant iterator); 
  state = singular; 
} 
 
 
For some reason, I fail to see why I shouldn't be allowed to copy-construct from an 
invalid iterator. After all, the result would still be invalid and couldn't be dereferenced, no? 
I think this should be allowed. 
 
W.

-- 
           Summary: Can't have vectors of vector::const_iterator
           Product: gcc
           Version: 3.4.0
            Status: UNCONFIRMED
          Keywords: rejects-valid
          Severity: normal
          Priority: P2
         Component: libstdc++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: bangerth at dealii dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523

[Bug libstdc++/15523] Can't have vectors of vector::const_iterator

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-05-18 20:36 -------
Even this one fails:
#include <vector>

int main ()
{
  std::vector<std::vector<int>::iterator> x(2);
}

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523

Re: [Bug libstdc++/15523] New: Can't have vectors of vector::const_iterator

[llewelly]

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

> I definitely like the debug mode in libstdc++, but happened to fall over this: 
> ----------------- 
> #include <vector> 
>  
> int main () 
> { 
>   std::vector<std::vector<int>::const_iterator> x(2); 
> } 
> ----------------- 
>  
> When compiled with -D_GLIBCXX_DEBUG -D_GLIBCXX_DEBUG_PEDANTIC, I got this: 
>  
> homes/csm2/bangerth/bin/gcc-3.4.0/bin/../lib/gcc/i686-pc-linux-gnu/3.4.0/../../../../include/c++/3.4.0/debug/safe_iterator.h:125: 
>     error: attempt to copy-construct an iterator from a singular iterator. 
>  
> Objects involved in the operation: 
> iterator "this" @ 0x0x8067ee0 { 
> type = 
> N11__gnu_debug14_Safe_iteratorIN9__gnu_cxx17__normal_iteratorIPKiN10__gnu_norm6vectorIiSaIiEEEEEN15__gnu_debug_def6vectorIiS7_EEEE 
> (constant iterator); 
>   state = singular; 
> } 
> iterator "other" @ 0x0xbfffdd40 { 
> type = 
> N11__gnu_debug14_Safe_iteratorIN9__gnu_cxx17__normal_iteratorIPKiN10__gnu_norm6vectorIiSaIiEEEEEN15__gnu_debug_def6vectorIiS7_EEEE 
> (constant iterator); 
>   state = singular; 
> } 
>  
>  
> For some reason, I fail to see why I shouldn't be allowed to copy-construct from an 
> invalid iterator. After all, the result would still be invalid and
> couldn't be dereferenced, no?

Copying an invalid iterator is undefined behavior. 24.1/5 .

> I think this should be allowed. 

Is there a gcc target where (a) loading an invalid address into an
    address register causes a hardware fault, and (b) copy
    constructing an invalid iterator might require such a load?

[Bug libstdc++/15523] Can't have vectors of vector::const_iterator

[llewelly at xmission dot com]

------- Additional Comments From llewelly at xmission dot com  2004-05-19 05:11 -------
Subject: Re:  New: Can't have vectors of vector::const_iterator

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

> I definitely like the debug mode in libstdc++, but happened to fall over this: 
> ----------------- 
> #include <vector> 
>  
> int main () 
> { 
>   std::vector<std::vector<int>::const_iterator> x(2); 
> } 
> ----------------- 
>  
> When compiled with -D_GLIBCXX_DEBUG -D_GLIBCXX_DEBUG_PEDANTIC, I got this: 
>  
> homes/csm2/bangerth/bin/gcc-3.4.0/bin/../lib/gcc/i686-pc-linux-gnu/3.4.0/../../../../include/c++/3.4.0/debug/safe_iterator.h:125: 
>     error: attempt to copy-construct an iterator from a singular iterator. 
>  
> Objects involved in the operation: 
> iterator "this" @ 0x0x8067ee0 { 
> type = 
> N11__gnu_debug14_Safe_iteratorIN9__gnu_cxx17__normal_iteratorIPKiN10__gnu_norm6vectorIiSaIiEEEEEN15__gnu_debug_def6vectorIiS7_EEEE 
> (constant iterator); 
>   state = singular; 
> } 
> iterator "other" @ 0x0xbfffdd40 { 
> type = 
> N11__gnu_debug14_Safe_iteratorIN9__gnu_cxx17__normal_iteratorIPKiN10__gnu_norm6vectorIiSaIiEEEEEN15__gnu_debug_def6vectorIiS7_EEEE 
> (constant iterator); 
>   state = singular; 
> } 
>  
>  
> For some reason, I fail to see why I shouldn't be allowed to copy-construct from an 
> invalid iterator. After all, the result would still be invalid and
> couldn't be dereferenced, no?

Copying an invalid iterator is undefined behavior. 24.1/5 .

> I think this should be allowed. 

Is there a gcc target where (a) loading an invalid address into an
    address register causes a hardware fault, and (b) copy
    constructing an invalid iterator might require such a load?


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523

[Bug libstdc++/15523] Can't have vectors of vector::const_iterator

[bangerth at dealii dot org]

------- Additional Comments From bangerth at dealii dot org  2004-05-19 14:24 -------
I see your point, although 24.1/5 only speaks about "most operations" and 
does not specifically rule out that we do the sensible thing here. I 
think my point is that I fail to see the value of this check, since it 
seems to be allowed to create such an iterator, but not to copy it. On 
the other hand, if we simply omitted the check we would fall over later 
if we ever tried to dereference it. The only thing that one would have 
to make sure is that the result of assigning a singular iterator to 
another iterator is again a singular iterator, but that should be what 
happens anyway if we simply copy all member variables. 
 
I don't feel strongly either way, since I already fixed my code to 
work around this, but I do feel that there are cases where one would 
like to generate a vector of singular iterators, and only after that 
assign individual values to them. 
 
W. 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523

[Bug libstdc++/15523] Can't have vectors of vector::const_iterator

[bangerth at ices dot utexas dot edu]

------- Additional Comments From bangerth at ices dot utexas dot edu  2004-05-19 17:39 -------
Subject: Re:  Can't have vectors of vector::const_iterator


> I think in most cases it would be sufficient to create an empty
>     vector, set it its vector<>::capacity(), and then push_back() new
>     values into it.

That's exactly what I ended up doing in our code.


> My naive expectation would be that -D_GLIBCXX_DEBUG_PEDANTIC would
>     cause an abort() for all dectectable undefined behavior. I think
>     most other users would expect this as well, *but* many probably
>     don't realize this extends to aborting on the copy of a singular
>     iterator, much less to aborting on the creation of the vector full
>     of singular iterators. OTOH, some users expect implementations to
>     report errors they don't know about.

As I said, I don't feel strongly way, I'm just confused because I don't see a 
reaonsing behind this particular check. What harm does it do to copy an 
object that you will not be allowed to use anyway? Since the standard says 
that behavior is undefined, we have some leeway in implementing sensible 
behavior, in particular since we know that this can never hurt anyone.

But I'm fine if we decide that this is NAD and that we should close this PR. 
Please feel free to do so if you want.

W.

-------------------------------------------------------------------------
Wolfgang Bangerth              email:            bangerth@ices.utexas.edu
                               www: http://www.ices.utexas.edu/~bangerth/



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523

Re: [Bug libstdc++/15523] Can't have vectors of vector::const_iterator

[llewelly]

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

> ------- Additional Comments From bangerth at dealii dot org  2004-05-19 14:24 -------
> I see your point, although 24.1/5 only speaks about "most operations" and 
> does not specifically rule out that we do the sensible thing here. I 
> think my point is that I fail to see the value of this check, since it 
> seems to be allowed to create such an iterator, but not to copy it. On 
> the other hand, if we simply omitted the check we would fall over later 
> if we ever tried to dereference it. The only thing that one would have 
> to make sure is that the result of assigning a singular iterator to 
> another iterator is again a singular iterator, but that should be what 
> happens anyway if we simply copy all member variables. 
>  
> I don't feel strongly either way, since I already fixed my code to 
> work around this, but I do feel that there are cases where one would 
> like to generate a vector of singular iterators, and only after that 
> assign individual values to them. 

The obvious answer is that if one can't initialize a vector of
    iterators to the 'right' value, one should initialize them to the
    null iterator. :-) (I know, pointers are the only iterators for
    which such a value exists.)

I think in most cases it would be sufficient to create an empty
    vector, set it its vector<>::capacity(), and then push_back() new
    values into it.

My naive expectation would be that -D_GLIBCXX_DEBUG_PEDANTIC would
    cause an abort() for all dectectable undefined behavior. I think
    most other users would expect this as well, *but* many probably
    don't realize this extends to aborting on the copy of a singular
    iterator, much less to aborting on the creation of the vector full
    of singular iterators. OTOH, some users expect implementations to
    report errors they don't know about.
    

[Bug libstdc++/15523] Can't have vectors of vector::const_iterator

[llewelly at xmission dot com]

------- Additional Comments From llewelly at xmission dot com  2004-05-19 17:32 -------
Subject: Re:  Can't have vectors of vector::const_iterator

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

> ------- Additional Comments From bangerth at dealii dot org  2004-05-19 14:24 -------
> I see your point, although 24.1/5 only speaks about "most operations" and 
> does not specifically rule out that we do the sensible thing here. I 
> think my point is that I fail to see the value of this check, since it 
> seems to be allowed to create such an iterator, but not to copy it. On 
> the other hand, if we simply omitted the check we would fall over later 
> if we ever tried to dereference it. The only thing that one would have 
> to make sure is that the result of assigning a singular iterator to 
> another iterator is again a singular iterator, but that should be what 
> happens anyway if we simply copy all member variables. 
>  
> I don't feel strongly either way, since I already fixed my code to 
> work around this, but I do feel that there are cases where one would 
> like to generate a vector of singular iterators, and only after that 
> assign individual values to them. 

The obvious answer is that if one can't initialize a vector of
    iterators to the 'right' value, one should initialize them to the
    null iterator. :-) (I know, pointers are the only iterators for
    which such a value exists.)

I think in most cases it would be sufficient to create an empty
    vector, set it its vector<>::capacity(), and then push_back() new
    values into it.

My naive expectation would be that -D_GLIBCXX_DEBUG_PEDANTIC would
    cause an abort() for all dectectable undefined behavior. I think
    most other users would expect this as well, *but* many probably
    don't realize this extends to aborting on the copy of a singular
    iterator, much less to aborting on the creation of the vector full
    of singular iterators. OTOH, some users expect implementations to
    report errors they don't know about.
    


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523

[Bug libstdc++/15523] Can't have vectors of vector::const_iterator

[llewelly at xmission dot com]

------- Additional Comments From llewelly at xmission dot com  2004-05-19 18:22 -------
Subject: Re:  Can't have vectors of vector::const_iterator

"bangerth at ices dot utexas dot edu" <gcc-bugzilla@gcc.gnu.org> writes:

> ------- Additional Comments From bangerth at ices dot utexas dot edu  2004-05-19 17:39 -------
> Subject: Re:  Can't have vectors of vector::const_iterator
> 
> 
> > I think in most cases it would be sufficient to create an empty
> >     vector, set it its vector<>::capacity(), and then push_back() new
> >     values into it.
> 
> That's exactly what I ended up doing in our code.
> 
> 
> > My naive expectation would be that -D_GLIBCXX_DEBUG_PEDANTIC would
> >     cause an abort() for all dectectable undefined behavior. I think
> >     most other users would expect this as well, *but* many probably
> >     don't realize this extends to aborting on the copy of a singular
> >     iterator, much less to aborting on the creation of the vector full
> >     of singular iterators. OTOH, some users expect implementations to
> >     report errors they don't know about.
> 
> As I said, I don't feel strongly way, I'm just confused because I don't see a 
> reaonsing behind this particular check. What harm does it do to copy an 
> object that you will not be allowed to use anyway?

I can only speculate as to the reasoning behind the check, but the
    example is undefined behavior. The check prevents an unsuspecting
    user from writing code which may misbehave on another
    implementation. 

In theory, such code may not be portable to other implementations. In
    practice, I don't know of an implementation in which copying an
    invalid iterator is a significant problem. But then, I mostly only
    use libstdc++ . :-)

I don't really know how far libstdc++ should go in emitting errors for
    non-conforming code. I did expect -D_GLIBCXX_DEBUG_PEDANTIC to
    cause that abort, and mildly prefer that it continue to do so, but
    I don't know how other users would react to it.

> Since the standard says 
> that behavior is undefined, we have some leeway in implementing sensible 
> behavior, in particular since we know that this can never hurt
> anyone.

I don't see this as being about whether gcc can implement sensible
    behavior for this case. My question is, should libstdc++ emit an
    error for this case, because some *other* implementation may not
    implement a sensible behavior for this case? The safe answer seems
    to be yes, but if nobody knows of an implementation where copying
    invalid pointers or iterators has bad behavior, maybe it's just
    paranoia. 

> 
> But I'm fine if we decide that this is NAD and that we should close this PR. 
> Please feel free to do so if you want.

I'm just an overly talkative observer. I don't close bugs. :-)


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523

[Bug libstdc++/15523] Can't have vectors of vector::const_iterator

[sebor at roguewave dot com]

------- Additional Comments From sebor at roguewave dot com  2004-05-19 18:04 -------
Subject: Re:  Can't have vectors of vector::const_iterator

FWIW, library issue 408 deals with something similar:
vector<reverse_iterator<char*> >

http://www.open-std.org/jtc1/sc22/wg21/prot/14882fdis/n1635.html#408

Martin



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523

Re: [Bug libstdc++/15523] Can't have vectors of vector::const_iterator

[llewelly]

"bangerth at ices dot utexas dot edu" <gcc-bugzilla@gcc.gnu.org> writes:

> ------- Additional Comments From bangerth at ices dot utexas dot edu  2004-05-19 17:39 -------
> Subject: Re:  Can't have vectors of vector::const_iterator
> 
> 
> > I think in most cases it would be sufficient to create an empty
> >     vector, set it its vector<>::capacity(), and then push_back() new
> >     values into it.
> 
> That's exactly what I ended up doing in our code.
> 
> 
> > My naive expectation would be that -D_GLIBCXX_DEBUG_PEDANTIC would
> >     cause an abort() for all dectectable undefined behavior. I think
> >     most other users would expect this as well, *but* many probably
> >     don't realize this extends to aborting on the copy of a singular
> >     iterator, much less to aborting on the creation of the vector full
> >     of singular iterators. OTOH, some users expect implementations to
> >     report errors they don't know about.
> 
> As I said, I don't feel strongly way, I'm just confused because I don't see a 
> reaonsing behind this particular check. What harm does it do to copy an 
> object that you will not be allowed to use anyway?

I can only speculate as to the reasoning behind the check, but the
    example is undefined behavior. The check prevents an unsuspecting
    user from writing code which may misbehave on another
    implementation. 

In theory, such code may not be portable to other implementations. In
    practice, I don't know of an implementation in which copying an
    invalid iterator is a significant problem. But then, I mostly only
    use libstdc++ . :-)

I don't really know how far libstdc++ should go in emitting errors for
    non-conforming code. I did expect -D_GLIBCXX_DEBUG_PEDANTIC to
    cause that abort, and mildly prefer that it continue to do so, but
    I don't know how other users would react to it.

> Since the standard says 
> that behavior is undefined, we have some leeway in implementing sensible 
> behavior, in particular since we know that this can never hurt
> anyone.

I don't see this as being about whether gcc can implement sensible
    behavior for this case. My question is, should libstdc++ emit an
    error for this case, because some *other* implementation may not
    implement a sensible behavior for this case? The safe answer seems
    to be yes, but if nobody knows of an implementation where copying
    invalid pointers or iterators has bad behavior, maybe it's just
    paranoia. 

> 
> But I'm fine if we decide that this is NAD and that we should close this PR. 
> Please feel free to do so if you want.

I'm just an overly talkative observer. I don't close bugs. :-)

[Bug libstdc++/15523] Can't have vectors of vector::const_iterator

[bangerth at ices dot utexas dot edu]

------- Additional Comments From bangerth at ices dot utexas dot edu  2004-05-19 18:28 -------
Subject: Re:  Can't have vectors of vector::const_iterator


> I'm just an overly talkative observer. I don't close bugs. :-)

I do quite frequently, but here I'd say it's up to the libstdc++ maintainers.

W.

-------------------------------------------------------------------------
Wolfgang Bangerth              email:            bangerth@ices.utexas.edu
                               www: http://www.ices.utexas.edu/~bangerth/



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523

Re: [Bug libstdc++/15523] Can't have vectors of vector::const_iterator

[llewelly]

"sebor at roguewave dot com" <gcc-bugzilla@gcc.gnu.org> writes:

> ------- Additional Comments From sebor at roguewave dot com  2004-05-19 18:04 -------
> Subject: Re:  Can't have vectors of vector::const_iterator
> 
> FWIW, library issue 408 deals with something similar:
> vector<reverse_iterator<char*> >
> 
> http://www.open-std.org/jtc1/sc22/wg21/prot/14882fdis/n1635.html#408

For those who haven't a comittee username & pw:

http://www.open-std.org/JTC1/SC22/WG21/docs/lwg-active.html#408

[Bug libstdc++/15523] Can't have vectors of vector::const_iterator

[llewelly at xmission dot com]

------- Additional Comments From llewelly at xmission dot com  2004-05-20 05:50 -------
Subject: Re:  Can't have vectors of vector::const_iterator

"sebor at roguewave dot com" <gcc-bugzilla@gcc.gnu.org> writes:

> ------- Additional Comments From sebor at roguewave dot com  2004-05-19 18:04 -------
> Subject: Re:  Can't have vectors of vector::const_iterator
> 
> FWIW, library issue 408 deals with something similar:
> vector<reverse_iterator<char*> >
> 
> http://www.open-std.org/jtc1/sc22/wg21/prot/14882fdis/n1635.html#408

For those who haven't a comittee username & pw:

http://www.open-std.org/JTC1/SC22/WG21/docs/lwg-active.html#408


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523

[Bug libstdc++/15523] Can't have vectors of vector::const_iterator

[bkoz at gcc dot gnu dot org]

------- Additional Comments From bkoz at gcc dot gnu dot org  2004-05-24 16:53 -------

I think we should either close this NAD, or suspend while waiting for the
standards committed to figure out precise semantics. 

Since 14990 is suspended for similar reasons, I suggest suspending.

-benjamin

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523

[Bug libstdc++/15523] [DR 408] Can't have vectors of vector::const_iterator

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-06-20 06:53 -------
Confirming to ...

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
   Last reconfirmed|0000-00-00 00:00:00         |2004-06-20 06:53:01
               date|                            |
            Summary|Can't have vectors of       |[DR 408] Can't have vectors
                   |vector::const_iterator      |of vector::const_iterator


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523

[Bug libstdc++/15523] [DR 408] Can't have vectors of vector::const_iterator

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2004-06-20 06:53 -------
suspending while waiting.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |SUSPENDED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523

[Bug libstdc++/15523] [DR 408] Can't have vectors of vector::const_iterator

[polzin_spamprotect_ at gmx dot de]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 615 bytes --]


------- Additional Comments From polzin_spamprotect_ at gmx dot de  2005-01-13 13:30 -------
I just want to add the information that unfortunately already
"-D_GLIBCXX_DEBUG" turns on the abort, you don't need the PEDANTIC.

I find this annoying, because in my case rewriting is not so easy, because
I store a struct of different iterators in a vector, and this information
is gathered together one after the other and there is no scope, where all 
containers exist together. Thus, it´s not possible to initialize the struct
without a GLIBCXX_DEBUG abort.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523

[Bug libstdc++/15523] [DR 408] Can't have vectors of vector::const_iterator

[paolo dot carlini at oracle dot com]

------- Comment #15 from paolo dot carlini at oracle dot com  2009-08-04 13:04 -------
Fixed.


-- 

paolo dot carlini at oracle dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED
   Target Milestone|---                         |4.5.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523

[Bug libstdc++/15523] [DR 408] Can't have vectors of vector::const_iterator

[paolo at gcc dot gnu dot org]

------- Comment #14 from paolo at gcc dot gnu dot org  2009-08-04 13:01 -------
Subject: Bug 15523

Author: paolo
Date: Tue Aug  4 13:01:08 2009
New Revision: 150455

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=150455
Log:
2009-08-04  Paolo Carlini  <paolo.carlini@oracle.com>

        PR libstdc++/15523
        * include/debug/safe_iterator.h (_Safe_iterator<>::
        _Safe_iterator(const _Safe_iterator&), _Safe_iterator<>::
        operator=(const _Safe_iterator&)): Implement resolution of DR 408,
        do not error out when the source is a value-initialized iterator.
        * testsuite/23_containers/vector/15523.cc: New.
        * doc/xml/manual/intro.xml: Add an entry for DR 408.

Added:
    trunk/libstdc++-v3/testsuite/23_containers/vector/15523.cc
Modified:
    trunk/libstdc++-v3/ChangeLog
    trunk/libstdc++-v3/doc/xml/manual/intro.xml
    trunk/libstdc++-v3/include/debug/safe_iterator.h


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523

[Bug libstdc++/15523] [DR 408] Can't have vectors of vector::const_iterator

[paolo dot carlini at oracle dot com]

-- 

paolo dot carlini at oracle dot com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|unassigned at gcc dot gnu   |paolo dot carlini at oracle
                   |dot org                     |dot com
             Status|SUSPENDED                   |ASSIGNED


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15523