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| author | redi <redi@138bc75d-0d04-0410-961f-82ee72b054a4> | 2014-10-01 12:34:04 +0000 |
|---|---|---|
| committer | redi <redi@138bc75d-0d04-0410-961f-82ee72b054a4> | 2014-10-01 12:34:04 +0000 |
| commit | 9b574f1ece055ed1ad5ba32bc9ce570e9d9e2b29 (patch) | |
| tree | 8122d9235d871ae80b24764f5092204a5d8dc966 /libstdc++-v3/include/bits | |
| parent | 2a3c6015d629ceee979449dda033393056a7eb55 (diff) | |
| download | ppe42-gcc-9b574f1ece055ed1ad5ba32bc9ce570e9d9e2b29.tar.gz ppe42-gcc-9b574f1ece055ed1ad5ba32bc9ce570e9d9e2b29.zip | |
PR libstdc++/59603
* include/bits/stl_algo.h (random_shuffle): Prevent self-swapping.
* testsuite/25_algorithms/random_shuffle/59603.cc: New.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_9-branch@215754 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'libstdc++-v3/include/bits')
| -rw-r--r-- | libstdc++-v3/include/bits/stl_algo.h | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/libstdc++-v3/include/bits/stl_algo.h b/libstdc++-v3/include/bits/stl_algo.h index 4c6ca8a7268..cfb50a92884 100644 --- a/libstdc++-v3/include/bits/stl_algo.h +++ b/libstdc++-v3/include/bits/stl_algo.h @@ -4430,7 +4430,12 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO if (__first != __last) for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i) - std::iter_swap(__i, __first + (std::rand() % ((__i - __first) + 1))); + { + _RandomAccessIterator __j = __first + + std::rand() % ((__i - __first) + 1); + if (__i != __j) + std::iter_swap(__i, __j); + } } /** @@ -4464,7 +4469,11 @@ _GLIBCXX_BEGIN_NAMESPACE_ALGO if (__first == __last) return; for (_RandomAccessIterator __i = __first + 1; __i != __last; ++__i) - std::iter_swap(__i, __first + __rand((__i - __first) + 1)); + { + _RandomAccessIterator __j = __first + __rand((__i - __first) + 1); + if (__i != __j) + std::iter_swap(__i, __j); + } } |
