[cfe-commits] [libcxx] r117098 - /libcxx/trunk/include/algorithm

[Howard Hinnant]

Author: hhinnant
Date: Fri Oct 22 10:26:39 2010
New Revision: 117098

URL: http://llvm.org/viewvc/llvm-project?rev=117098&view=rev
Log:
Fixed bug in random_shuffle to avoid swapping with self

Modified:
    libcxx/trunk/include/algorithm

Modified: libcxx/trunk/include/algorithm
URL: 
http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/algorithm?rev=117098&r1=117097&r2=117098&view=diff
==============================================================================
--- libcxx/trunk/include/algorithm (original)
+++ libcxx/trunk/include/algorithm Fri Oct 22 10:26:39 2010
@@ -2686,7 +2686,11 @@
         _D __uid;
         __rs_default __g = __rs_get();
         for (--__last, --__d; __first < __last; ++__first, --__d)
-            swap(*__first, *(__first + __uid(__g, _P(0, __d))));
+        {
+            difference_type __i = __uid(__g, _P(0, __d));
+            if (__i != difference_type(0))
+                swap(*__first, *(__first + __i));
+        }
     }
 }
 
@@ -2704,7 +2708,10 @@
     if (__d > 1)
     {
         for (--__last; __first < __last; ++__first, --__d)
-            swap(*__first, *(__first + __rand(__d)));
+        {
+            difference_type __i = __rand(__d);
+            swap(*__first, *(__first + __i));
+        }
     }
 }
 
@@ -2720,7 +2727,11 @@
     {
         _D __uid;
         for (--__last, --__d; __first < __last; ++__first, --__d)
-            swap(*__first, *(__first + __uid(__g, _P(0, __d))));
+        {
+            difference_type __i = __uid(__g, _P(0, __d));
+            if (__i != difference_type(0))
+                swap(*__first, *(__first + __i));
+        }
     }
 }
 


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