DR 488
authorredi <redi@138bc75d-0d04-0410-961f-82ee72b054a4>
Sat, 17 Jan 2015 03:15:52 +0000 (03:15 +0000)
committerredi <redi@138bc75d-0d04-0410-961f-82ee72b054a4>
Sat, 17 Jan 2015 03:15:52 +0000 (03:15 +0000)
PR libstdc++/58357
* include/bits/algorithmfwd.h (rotate): Return an iterator.
* include/bits/stl_algo.h (rotate, __rotate): Likewise.
* testsuite/25_algorithms/rotate/dr488.cc: New.
* testsuite/25_algorithms/rotate/check_type.cc: Adjust function type.
* testsuite/25_algorithms/rotate/requirements/explicit_instantiation/
2.cc: Likewise.
* testsuite/25_algorithms/rotate/requirements/explicit_instantiation/
pod.cc: Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@219793 138bc75d-0d04-0410-961f-82ee72b054a4

libstdc++-v3/ChangeLog
libstdc++-v3/include/bits/algorithmfwd.h
libstdc++-v3/include/bits/stl_algo.h
libstdc++-v3/testsuite/25_algorithms/rotate/check_type.cc
libstdc++-v3/testsuite/25_algorithms/rotate/dr488.cc [new file with mode: 0644]
libstdc++-v3/testsuite/25_algorithms/rotate/requirements/explicit_instantiation/2.cc
libstdc++-v3/testsuite/25_algorithms/rotate/requirements/explicit_instantiation/pod.cc

index 1dc68e7..4b151e9 100644 (file)
@@ -1,5 +1,18 @@
 2015-01-17  Jonathan Wakely  <jwakely@redhat.com>
 
+       DR 488
+       PR libstdc++/58357
+       * include/bits/algorithmfwd.h (rotate): Return an iterator.
+       * include/bits/stl_algo.h (rotate, __rotate): Likewise.
+       * testsuite/25_algorithms/rotate/dr488.cc: New.
+       * testsuite/25_algorithms/rotate/check_type.cc: Adjust function type.
+       * testsuite/25_algorithms/rotate/requirements/explicit_instantiation/
+       2.cc: Likewise.
+       * testsuite/25_algorithms/rotate/requirements/explicit_instantiation/
+       pod.cc: Likewise.
+
+2015-01-17  Jonathan Wakely  <jwakely@redhat.com>
+
        PR libstdc++/60940
        * include/bits/atomic_base.h: Remove atomic integral typedefs as
        synonyms for __atomic_base<int> etc.
index 283c5e6..11361bb 100644 (file)
@@ -531,7 +531,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     reverse_copy(_BIter, _BIter, _OIter);
 
   template<typename _FIter>
-    void 
+    _FIter
     rotate(_FIter, _FIter, _FIter);
 
   template<typename _FIter, typename _OIter>
index da642e6..3325b94 100644 (file)
@@ -1239,14 +1239,16 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
 
   /// This is a helper function for the rotate algorithm.
   template<typename _ForwardIterator>
-    void
+    _ForwardIterator
     __rotate(_ForwardIterator __first,
             _ForwardIterator __middle,
             _ForwardIterator __last,
             forward_iterator_tag)
     {
-      if (__first == __middle || __last  == __middle)
-       return;
+      if (__first == __middle)
+       return __last;
+      else if (__last  == __middle)
+       return __first;
 
       _ForwardIterator __first2 = __middle;
       do
@@ -1259,6 +1261,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        }
       while (__first2 != __last);
 
+      _ForwardIterator __ret = __first;
+
       __first2 = __middle;
 
       while (__first2 != __last)
@@ -1271,11 +1275,12 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
          else if (__first2 == __last)
            __first2 = __middle;
        }
+      return __ret;
     }
 
    /// This is a helper function for the rotate algorithm.
   template<typename _BidirectionalIterator>
-    void
+    _BidirectionalIterator
     __rotate(_BidirectionalIterator __first,
             _BidirectionalIterator __middle,
             _BidirectionalIterator __last,
@@ -1285,8 +1290,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       __glibcxx_function_requires(_Mutable_BidirectionalIteratorConcept<
                                  _BidirectionalIterator>)
 
-      if (__first == __middle || __last  == __middle)
-       return;
+      if (__first == __middle)
+       return __last;
+      else if (__last  == __middle)
+       return __first;
 
       std::__reverse(__first,  __middle, bidirectional_iterator_tag());
       std::__reverse(__middle, __last,   bidirectional_iterator_tag());
@@ -1298,14 +1305,20 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
        }
 
       if (__first == __middle)
-       std::__reverse(__middle, __last,   bidirectional_iterator_tag());
+       {
+         std::__reverse(__middle, __last,   bidirectional_iterator_tag());
+         return __last;
+       }
       else
-       std::__reverse(__first,  __middle, bidirectional_iterator_tag());
+       {
+         std::__reverse(__first,  __middle, bidirectional_iterator_tag());
+         return __first;
+       }
     }
 
   /// This is a helper function for the rotate algorithm.
   template<typename _RandomAccessIterator>
-    void
+    _RandomAccessIterator
     __rotate(_RandomAccessIterator __first,
             _RandomAccessIterator __middle,
             _RandomAccessIterator __last,
@@ -1315,8 +1328,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       __glibcxx_function_requires(_Mutable_RandomAccessIteratorConcept<
                                  _RandomAccessIterator>)
 
-      if (__first == __middle || __last  == __middle)
-       return;
+      if (__first == __middle)
+       return __last;
+      else if (__last  == __middle)
+       return __first;
 
       typedef typename iterator_traits<_RandomAccessIterator>::difference_type
        _Distance;
@@ -1329,10 +1344,11 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       if (__k == __n - __k)
        {
          std::swap_ranges(__first, __middle, __middle);
-         return;
+         return __middle;
        }
 
       _RandomAccessIterator __p = __first;
+      _RandomAccessIterator __ret = __first + (__last - __middle);
 
       for (;;)
        {
@@ -1343,7 +1359,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
                  _ValueType __t = _GLIBCXX_MOVE(*__p);
                  _GLIBCXX_MOVE3(__p + 1, __p + __n, __p);
                  *(__p + __n - 1) = _GLIBCXX_MOVE(__t);
-                 return;
+                 return __ret;
                }
              _RandomAccessIterator __q = __p + __k;
              for (_Distance __i = 0; __i < __n - __k; ++ __i)
@@ -1354,7 +1370,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
                }
              __n %= __k;
              if (__n == 0)
-               return;
+               return __ret;
              std::swap(__n, __k);
              __k = __n - __k;
            }
@@ -1366,7 +1382,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
                  _ValueType __t = _GLIBCXX_MOVE(*(__p + __n - 1));
                  _GLIBCXX_MOVE_BACKWARD3(__p, __p + __n - 1, __p + __n);
                  *__p = _GLIBCXX_MOVE(__t);
-                 return;
+                 return __ret;
                }
              _RandomAccessIterator __q = __p + __n;
              __p = __q - __k;
@@ -1378,19 +1394,21 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
                }
              __n %= __k;
              if (__n == 0)
-               return;
+               return __ret;
              std::swap(__n, __k);
            }
        }
     }
 
+   // _GLIBCXX_RESOLVE_LIB_DEFECTS
+   // DR 488. rotate throws away useful information
   /**
    *  @brief Rotate the elements of a sequence.
    *  @ingroup mutating_algorithms
    *  @param  __first   A forward iterator.
    *  @param  __middle  A forward iterator.
    *  @param  __last    A forward iterator.
-   *  @return  Nothing.
+   *  @return  first + (last - middle).
    *
    *  Rotates the elements of the range @p [__first,__last) by 
    *  @p (__middle - __first) positions so that the element at @p __middle
@@ -1406,7 +1424,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
    *  for each @p n in the range @p [0,__last-__first).
   */
   template<typename _ForwardIterator>
-    inline void
+    inline _ForwardIterator
     rotate(_ForwardIterator __first, _ForwardIterator __middle,
           _ForwardIterator __last)
     {
@@ -1416,8 +1434,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       __glibcxx_requires_valid_range(__first, __middle);
       __glibcxx_requires_valid_range(__middle, __last);
 
-      std::__rotate(__first, __middle, __last,
-                   std::__iterator_category(__first));
+      return std::__rotate(__first, __middle, __last,
+                          std::__iterator_category(__first));
     }
 
   /**
index f464364..9d4c382 100644 (file)
@@ -26,19 +26,19 @@ struct X { };
 
 bool operator<(X,X) { return true;}
 
-void
+__gnu_test::forward_iterator_wrapper<X>
 test1(__gnu_test::forward_iterator_wrapper<X>& begin,
       __gnu_test::forward_iterator_wrapper<X>& middle,
       __gnu_test::forward_iterator_wrapper<X>& end)
 { return std::rotate(begin,middle,end); }
 
-void
+__gnu_test::bidirectional_iterator_wrapper<X>
 test1(__gnu_test::bidirectional_iterator_wrapper<X>& begin,
       __gnu_test::bidirectional_iterator_wrapper<X>& middle,
       __gnu_test::bidirectional_iterator_wrapper<X>& end)
 { return std::rotate(begin,middle,end); }
 
-void
+__gnu_test::random_access_iterator_wrapper<X>
 test1(__gnu_test::random_access_iterator_wrapper<X>& begin,
       __gnu_test::random_access_iterator_wrapper<X>& middle,
       __gnu_test::random_access_iterator_wrapper<X>& end)
diff --git a/libstdc++-v3/testsuite/25_algorithms/rotate/dr488.cc b/libstdc++-v3/testsuite/25_algorithms/rotate/dr488.cc
new file mode 100644 (file)
index 0000000..60bd033
--- /dev/null
@@ -0,0 +1,77 @@
+// Copyright (C) 2015 Free Software Foundation, Inc.
+//
+// This file is part of the GNU ISO C++ Library.  This library is free
+// software; you can redistribute it and/or modify it under the
+// terms of the GNU General Public License as published by the
+// Free Software Foundation; either version 3, or (at your option)
+// any later version.
+
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License along
+// with this library; see the file COPYING3.  If not see
+// <http://www.gnu.org/licenses/>.
+
+// { dg-options "-std=gnu++11" }
+
+#include <algorithm>
+#include <iterator>
+#include <forward_list>
+#include <list>
+#include <vector>
+#include <testsuite_hooks.h>
+
+template<typename Container>
+void
+test(Container& c)
+{
+  int size = std::distance(c.begin(), c.end());
+  for (int i=0; i < size; ++i)
+  {
+    auto first = c.begin(), middle = std::next(first, i), last = c.end();
+    auto r = std::rotate(first, middle, last);
+    auto expected = std::next(first, std::distance(middle, last));
+    VERIFY( r == expected );
+  }
+}
+
+void
+test01()
+{
+  // test random access iterators
+  std::vector<int> v{ 0, 1, 2, 3, 4 };
+  test(v);
+  v.push_back(5);
+  test(v);
+}
+
+void
+test02()
+{
+  // test bidirectional iterators
+  std::list<int> l{ 0, 1, 2, 3, 4 };
+  test(l);
+  l.push_back(5);
+  test(l);
+}
+
+void
+test03()
+{
+  // test forward iterators
+  std::forward_list<int> l{ 0, 1, 2, 3, 4 };
+  test(l);
+  l.push_front(5);
+  test(l);
+}
+
+int
+main()
+{
+  test01();
+  test02();
+  test03();
+}
index d48e653..ec8c917 100644 (file)
@@ -30,5 +30,5 @@ namespace std
   typedef NonDefaultConstructible              value_type;
   typedef value_type*          iterator_type;
 
-  template void rotate(iterator_type, iterator_type, iterator_type);
+  template iterator_type rotate(iterator_type, iterator_type, iterator_type);
 } 
index 5804c63..c24ee70 100644 (file)
@@ -30,5 +30,5 @@ namespace std
   typedef pod_int              value_type;
   typedef value_type*          iterator_type;
 
-  template void rotate(iterator_type, iterator_type, iterator_type);
+  template iterator_type rotate(iterator_type, iterator_type, iterator_type);
 }