1 files changed, 63 insertions, 0 deletions
diff --git a/include/clang/Index/STLExtras.h b/include/clang/Index/STLExtras.h
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index 0000000000000..a3693c6c79a62
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+++ b/include/clang/Index/STLExtras.h
@@ -0,0 +1,63 @@
+//===--- STLExtras.h - Helper STL related templates -------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  Helper templates for using with the STL.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_INDEX_STLEXTRAS_H
+#define LLVM_CLANG_INDEX_STLEXTRAS_H
+
+namespace clang {
+
+namespace idx {
+
+/// \brief Wraps an iterator whose value_type is a pair, and provides
+/// pair's second object as the value.
+template <typename iter_type>
+class pair_value_iterator {
+  iter_type I;
+
+public:
+  typedef typename iter_type::value_type::second_type value_type;
+  typedef value_type& reference;
+  typedef value_type* pointer;
+  typedef typename iter_type::iterator_category iterator_category;
+  typedef typename iter_type::difference_type   difference_type;
+
+  pair_value_iterator() { }
+  pair_value_iterator(iter_type i) : I(i) { }
+
+  reference operator*() const { return I->second; }
+  pointer operator->() const { return &I->second; }
+
+  pair_value_iterator& operator++() {
+    ++I;
+    return *this;
+  }
+
+  pair_value_iterator operator++(int) {
+    pair_value_iterator tmp(*this);
+    ++(*this);
+    return tmp;
+  }
+
+  friend bool operator==(pair_value_iterator L, pair_value_iterator R) {
+    return L.I == R.I;
+  }
+  friend bool operator!=(pair_value_iterator L, pair_value_iterator R) {
+    return L.I != R.I;
+  }
+};
+
+} // end idx namespace
+
+} // end clang namespace
+
+#endif