1 files changed, 33 insertions, 1 deletions

diff --git a/include/llvm/ADT/iterator.h b/include/llvm/ADT/iterator.h
index 6470e09db86c..28dcdf9613ef 100644
--- a/include/llvm/ADT/iterator.h
+++ b/include/llvm/ADT/iterator.h
@@ -10,6 +10,7 @@
 #ifndef LLVM_ADT_ITERATOR_H
 #define LLVM_ADT_ITERATOR_H
 
+#include "llvm/ADT/iterator_range.h"
 #include <cstddef>
 #include <iterator>
 #include <type_traits>
@@ -91,6 +92,8 @@ protected:
 
 public:
   DerivedT operator+(DifferenceTypeT n) const {
+    static_assert(std::is_base_of<iterator_facade_base, DerivedT>::value,
+                  "Must pass the derived type to this template!");
     static_assert(
         IsRandomAccess,
         "The '+' operator is only defined for random access iterators.");
@@ -114,6 +117,8 @@ public:
   }
 
   DerivedT &operator++() {
+    static_assert(std::is_base_of<iterator_facade_base, DerivedT>::value,
+                  "Must pass the derived type to this template!");
     return static_cast<DerivedT *>(this)->operator+=(1);
   }
   DerivedT operator++(int) {
@@ -160,9 +165,15 @@ public:
     return !static_cast<const DerivedT *>(this)->operator<(RHS);
   }
 
+  PointerT operator->() { return &static_cast<DerivedT *>(this)->operator*(); }
   PointerT operator->() const {
     return &static_cast<const DerivedT *>(this)->operator*();
   }
+  ReferenceProxy operator[](DifferenceTypeT n) {
+    static_assert(IsRandomAccess,
+                  "Subscripting is only defined for random access iterators.");
+    return ReferenceProxy(static_cast<DerivedT *>(this)->operator+(n));
+  }
   ReferenceProxy operator[](DifferenceTypeT n) const {
     static_assert(IsRandomAccess,
                   "Subscripting is only defined for random access iterators.");
@@ -202,7 +213,10 @@ protected:
 
   iterator_adaptor_base() = default;
 
-  explicit iterator_adaptor_base(WrappedIteratorT u) : I(std::move(u)) {}
+  explicit iterator_adaptor_base(WrappedIteratorT u) : I(std::move(u)) {
+    static_assert(std::is_base_of<iterator_adaptor_base, DerivedT>::value,
+                  "Must pass the derived type to this template!");
+  }
 
   const WrappedIteratorT &wrapped() const { return I; }
 
@@ -283,6 +297,15 @@ struct pointee_iterator
   T &operator*() const { return **this->I; }
 };
 
+template <typename RangeT, typename WrappedIteratorT =
+                               decltype(std::begin(std::declval<RangeT>()))>
+iterator_range<pointee_iterator<WrappedIteratorT>>
+make_pointee_range(RangeT &&Range) {
+  using PointeeIteratorT = pointee_iterator<WrappedIteratorT>;
+  return make_range(PointeeIteratorT(std::begin(std::forward<RangeT>(Range))),
+                    PointeeIteratorT(std::end(std::forward<RangeT>(Range))));
+}
+
 template <typename WrappedIteratorT,
           typename T = decltype(&*std::declval<WrappedIteratorT>())>
 class pointer_iterator
@@ -300,6 +323,15 @@ public:
   const T &operator*() const { return Ptr = &*this->I; }
 };
 
+template <typename RangeT, typename WrappedIteratorT =
+                               decltype(std::begin(std::declval<RangeT>()))>
+iterator_range<pointer_iterator<WrappedIteratorT>>
+make_pointer_range(RangeT &&Range) {
+  using PointerIteratorT = pointer_iterator<WrappedIteratorT>;
+  return make_range(PointerIteratorT(std::begin(std::forward<RangeT>(Range))),
+                    PointerIteratorT(std::end(std::forward<RangeT>(Range))));
+}
+
 } // end namespace llvm
 
 #endif // LLVM_ADT_ITERATOR_H