Add non-member begin and end so that drop_begin works on iterator_range.

llvm-svn: 244620

1 files changed, 10 insertions, 0 deletions

diff --git a/llvm/include/llvm/ADT/iterator_range.h b/llvm/include/llvm/ADT/iterator_range.h
index 3dd679bd9b7..9ab1c9645b3 100644
--- a/llvm/include/llvm/ADT/iterator_range.h
+++ b/llvm/include/llvm/ADT/iterator_range.h
@@ -47,6 +47,16 @@ public:
   IteratorT end() const { return end_iterator; }
 };
 
+template <typename IteratorT>
+IteratorT begin(const iterator_range<IteratorT> &R) {
+  return R.begin();
+}
+
+template <typename IteratorT>
+IteratorT end(const iterator_range<IteratorT> &R) {
+  return R.end();
+}
+
 /// \brief Convenience function for iterating over sub-ranges.
 ///
 /// This provides a bit of syntactic sugar to make using sub-ranges