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* [Bug libstdc++/50119] New: copy_n advances InputIterator one more time than necessary
@ 2011-08-18 14:57 cubbi at cubbi dot org
2011-08-18 15:11 ` [Bug libstdc++/50119] " paolo.carlini at oracle dot com
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: cubbi at cubbi dot org @ 2011-08-18 14:57 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50119
Bug #: 50119
Summary: copy_n advances InputIterator one more time than
necessary
Classification: Unclassified
Product: gcc
Version: 4.7.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: libstdc++
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: cubbi@cubbi.org
The naive implementation of std::copy_n() incorrectly increments InputIterator
one more time than needed, which fails with single-pass input iterators such as
istream_iterator
Test program:
#include <algorithm>
#include <vector>
#include <sstream>
#include <iterator>
#include <iostream>
int main()
{
std::istringstream s("1 2 3 4 5");
std::vector<int> v;
copy_n(std::istream_iterator<int>(s), 2, back_inserter(v));
copy_n(std::istream_iterator<int>(s), 2, back_inserter(v));
copy(v.begin(), v.end(), std::ostream_iterator<int>(std::cout, " "));
std::cout << '\n';
}
Output with GCC 4.5.3 and 4.7.0-alpha20110716
1 2 4 5
expected output:
1 2 3 4
Similar bug was fixed in LLVM's libc++ in february 2011, the fix is
straightforward:
http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20110221/039404.html
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug libstdc++/50119] copy_n advances InputIterator one more time than necessary
2011-08-18 14:57 [Bug libstdc++/50119] New: copy_n advances InputIterator one more time than necessary cubbi at cubbi dot org
@ 2011-08-18 15:11 ` paolo.carlini at oracle dot com
2011-08-18 16:36 ` [Bug libstdc++/50119] [C++0x] " paolo at gcc dot gnu.org
2011-08-18 16:41 ` paolo.carlini at oracle dot com
2 siblings, 0 replies; 4+ messages in thread
From: paolo.carlini at oracle dot com @ 2011-08-18 15:11 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50119
Paolo Carlini <paolo.carlini at oracle dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Last reconfirmed| |2011-08-18
AssignedTo|unassigned at gcc dot |paolo.carlini at oracle dot
|gnu.org |com
Target Milestone|--- |4.7.0
Ever Confirmed|0 |1
--- Comment #1 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-08-18 15:03:26 UTC ---
Ok.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug libstdc++/50119] [C++0x] copy_n advances InputIterator one more time than necessary
2011-08-18 14:57 [Bug libstdc++/50119] New: copy_n advances InputIterator one more time than necessary cubbi at cubbi dot org
2011-08-18 15:11 ` [Bug libstdc++/50119] " paolo.carlini at oracle dot com
@ 2011-08-18 16:36 ` paolo at gcc dot gnu.org
2011-08-18 16:41 ` paolo.carlini at oracle dot com
2 siblings, 0 replies; 4+ messages in thread
From: paolo at gcc dot gnu.org @ 2011-08-18 16:36 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50119
--- Comment #2 from paolo at gcc dot gnu.org <paolo at gcc dot gnu.org> 2011-08-18 16:32:31 UTC ---
Author: paolo
Date: Thu Aug 18 16:32:23 2011
New Revision: 177871
URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=177871
Log:
2011-08-18 Paolo Carlini <paolo.carlini@oracle.com>
PR libstdc++/50119
* include/bits/stl_algo.h (__copy_n(_InputIterator, _Size,
_OutputIterator, input_iterator_tag)): Fix.
* testsuite/25_algorithms/copy_n/50119.cc: New.
Added:
trunk/libstdc++-v3/testsuite/25_algorithms/copy_n/50119.cc
Modified:
trunk/libstdc++-v3/ChangeLog
trunk/libstdc++-v3/include/bits/stl_algo.h
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug libstdc++/50119] [C++0x] copy_n advances InputIterator one more time than necessary
2011-08-18 14:57 [Bug libstdc++/50119] New: copy_n advances InputIterator one more time than necessary cubbi at cubbi dot org
2011-08-18 15:11 ` [Bug libstdc++/50119] " paolo.carlini at oracle dot com
2011-08-18 16:36 ` [Bug libstdc++/50119] [C++0x] " paolo at gcc dot gnu.org
@ 2011-08-18 16:41 ` paolo.carlini at oracle dot com
2 siblings, 0 replies; 4+ messages in thread
From: paolo.carlini at oracle dot com @ 2011-08-18 16:41 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50119
Paolo Carlini <paolo.carlini at oracle dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |FIXED
--- Comment #3 from Paolo Carlini <paolo.carlini at oracle dot com> 2011-08-18 16:36:16 UTC ---
Done, thanks!
^ permalink raw reply [flat|nested] 4+ messages in thread
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2011-08-18 14:57 [Bug libstdc++/50119] New: copy_n advances InputIterator one more time than necessary cubbi at cubbi dot org
2011-08-18 15:11 ` [Bug libstdc++/50119] " paolo.carlini at oracle dot com
2011-08-18 16:36 ` [Bug libstdc++/50119] [C++0x] " paolo at gcc dot gnu.org
2011-08-18 16:41 ` paolo.carlini at oracle dot com
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