1 files changed, 16 insertions, 0 deletions
diff --git a/internal/ceres/stl_util.h b/internal/ceres/stl_util.h
index a1a19e8..08f15ec 100644
--- a/internal/ceres/stl_util.h
+++ b/internal/ceres/stl_util.h
@@ -31,6 +31,8 @@
 #ifndef CERES_INTERNAL_STL_UTIL_H_
 #define CERES_INTERNAL_STL_UTIL_H_
 
+#include <algorithm>
+
 namespace ceres {
 
 // STLDeleteContainerPointers()
@@ -53,6 +55,20 @@ void STLDeleteContainerPointers(ForwardIterator begin,
   }
 }
 
+// Variant of STLDeleteContainerPointers which allows the container to
+// contain duplicates.
+template <class ForwardIterator>
+void STLDeleteUniqueContainerPointers(ForwardIterator begin,
+                                      ForwardIterator end) {
+  sort(begin, end);
+  ForwardIterator new_end = unique(begin, end);
+  while (begin != new_end) {
+    ForwardIterator temp = begin;
+    ++begin;
+    delete *temp;
+  }
+}
+
 // STLDeleteElements() deletes all the elements in an STL container and clears
 // the container.  This function is suitable for use with a vector, set,
 // hash_set, or any other STL container which defines sensible begin(), end(),