[libcxx] r227824 - Fix PR#22433. The algorithm is_partitioned was testing an item in the middle of the sequence twice.

[Marshall Clow]

Author: marshall
Date: Mon Feb  2 12:16:35 2015
New Revision: 227824

URL: http://llvm.org/viewvc/llvm-project?rev=227824&view=rev
Log:
Fix PR#22433. The algorithm is_partitioned was testing an item in the middle of the sequence twice.

Modified:
    libcxx/trunk/include/algorithm
    libcxx/trunk/test/std/algorithms/alg.modifying.operations/alg.partitions/is_partitioned.pass.cpp

Modified: libcxx/trunk/include/algorithm
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/algorithm?rev=227824&r1=227823&r2=227824&view=diff
==============================================================================
--- libcxx/trunk/include/algorithm (original)
+++ libcxx/trunk/include/algorithm Mon Feb  2 12:16:35 2015
@@ -3148,6 +3148,9 @@ is_partitioned(_InputIterator __first, _
     for (; __first != __last; ++__first)
         if (!__pred(*__first))
             break;
+    if ( __first == __last )
+        return true;
+    ++__first;
     for (; __first != __last; ++__first)
         if (__pred(*__first))
             return false;

Modified: libcxx/trunk/test/std/algorithms/alg.modifying.operations/alg.partitions/is_partitioned.pass.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/algorithms/alg.modifying.operations/alg.partitions/is_partitioned.pass.cpp?rev=227824&r1=227823&r2=227824&view=diff
==============================================================================
--- libcxx/trunk/test/std/algorithms/alg.modifying.operations/alg.partitions/is_partitioned.pass.cpp (original)
+++ libcxx/trunk/test/std/algorithms/alg.modifying.operations/alg.partitions/is_partitioned.pass.cpp Mon Feb  2 12:16:35 2015
@@ -17,6 +17,7 @@
 #include <cassert>
 
 #include "test_iterators.h"
+#include "counting_predicates.hpp"
 
 struct is_odd
 {
@@ -27,32 +28,50 @@ int main()
 {
     {
         const int ia[] = {1, 2, 3, 4, 5, 6};
+        unary_counting_predicate<is_odd, int> pred((is_odd()));
         assert(!std::is_partitioned(input_iterator<const int*>(std::begin(ia)),
                                     input_iterator<const int*>(std::end(ia)),
-                                    is_odd()));
+                                    std::ref(pred)));
+        assert(pred.count() <= std::distance(std::begin(ia), std::end(ia)));
     }
     {
         const int ia[] = {1, 3, 5, 2, 4, 6};
+        unary_counting_predicate<is_odd, int> pred((is_odd()));
         assert( std::is_partitioned(input_iterator<const int*>(std::begin(ia)),
                                     input_iterator<const int*>(std::end(ia)),
-                                    is_odd()));
+                                    std::ref(pred)));
+        assert(pred.count() <= std::distance(std::begin(ia), std::end(ia)));
     }
     {
         const int ia[] = {2, 4, 6, 1, 3, 5};
+        unary_counting_predicate<is_odd, int> pred((is_odd()));
         assert(!std::is_partitioned(input_iterator<const int*>(std::begin(ia)),
                                     input_iterator<const int*>(std::end(ia)),
-                                    is_odd()));
+                                    std::ref(pred)));
+        assert(pred.count() <= std::distance(std::begin(ia), std::end(ia)));
     }
     {
         const int ia[] = {1, 3, 5, 2, 4, 6, 7};
+        unary_counting_predicate<is_odd, int> pred((is_odd()));
         assert(!std::is_partitioned(input_iterator<const int*>(std::begin(ia)),
                                     input_iterator<const int*>(std::end(ia)),
-                                    is_odd()));
+                                    std::ref(pred)));
+        assert(pred.count() <= std::distance(std::begin(ia), std::end(ia)));
     }
     {
         const int ia[] = {1, 3, 5, 2, 4, 6, 7};
+        unary_counting_predicate<is_odd, int> pred((is_odd()));
         assert( std::is_partitioned(input_iterator<const int*>(std::begin(ia)),
                                     input_iterator<const int*>(std::begin(ia)),
-                                    is_odd()));
+                                    std::ref(pred)));
+        assert(pred.count() <= std::distance(std::begin(ia), std::begin(ia)));
+    }
+    {
+        const int ia[] = {1, 3, 5, 7, 9, 11, 2};
+        unary_counting_predicate<is_odd, int> pred((is_odd()));
+        assert( std::is_partitioned(input_iterator<const int*>(std::begin(ia)),
+                                    input_iterator<const int*>(std::end(ia)),
+                                    std::ref(pred)));
+        assert(pred.count() <= std::distance(std::begin(ia), std::end(ia)));
     }
 }