1 files changed, 25 insertions, 3 deletions
diff --git a/contrib/llvm-project/libcxx/include/__algorithm/iterator_operations.h b/contrib/llvm-project/libcxx/include/__algorithm/iterator_operations.h
index eb627e1ace7a..8307d71214e5 100644
--- a/contrib/llvm-project/libcxx/include/__algorithm/iterator_operations.h
+++ b/contrib/llvm-project/libcxx/include/__algorithm/iterator_operations.h
@@ -41,6 +41,7 @@ struct _IterOps<_RangeAlgPolicy> {
   static constexpr auto next = ranges::next;
   static constexpr auto __advance_to = ranges::advance;
 };
+
 #endif
 
 struct _ClassicAlgPolicy {};
@@ -65,11 +66,24 @@ struct _IterOps<_ClassicAlgPolicy> {
   // iter_move
   template <class _Iter>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
-  // Declaring the return type is necessary for the C++03 mode (which doesn't support placeholder return types).
-  static typename iterator_traits<__uncvref_t<_Iter> >::value_type&& __iter_move(_Iter&& __i) {
+      // Declaring the return type is necessary for C++03, so we basically mirror what `decltype(auto)` would deduce.
+      static __enable_if_t<
+          is_reference<typename iterator_traits<__uncvref_t<_Iter> >::reference>::value,
+          typename remove_reference< typename iterator_traits<__uncvref_t<_Iter> >::reference >::type&&>
+      __iter_move(_Iter&& __i) {
     return std::move(*std::forward<_Iter>(__i));
   }
 
+  template <class _Iter>
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
+      // Declaring the return type is necessary for C++03, so we basically mirror what `decltype(auto)` would deduce.
+      static __enable_if_t<
+          !is_reference<typename iterator_traits<__uncvref_t<_Iter> >::reference>::value,
+          typename iterator_traits<__uncvref_t<_Iter> >::reference>
+      __iter_move(_Iter&& __i) {
+    return *std::forward<_Iter>(__i);
+  }
+
   // iter_swap
   template <class _Iter1, class _Iter2>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
@@ -85,7 +99,15 @@ struct _IterOps<_ClassicAlgPolicy> {
   }
 
   template <class _Iter>
-  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_AFTER_CXX11 void __advance_to(_Iter& __first, _Iter __last) {
+  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_AFTER_CXX11
+  __uncvref_t<_Iter> next(_Iter&& __it, 
+                          typename iterator_traits<__uncvref_t<_Iter> >::difference_type __n = 1){
+    return std::next(std::forward<_Iter>(__it), __n);
+  }
+
+  template <class _Iter>
+  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_AFTER_CXX11
+  void __advance_to(_Iter& __first, _Iter __last) {
     __first = __last;
   }
 };