diff --git a/components/containers/partitioned_vector/include/hpx/components/containers/partitioned_vector/partitioned_vector_local_view_iterator.hpp b/components/containers/partitioned_vector/include/hpx/components/containers/partitioned_vector/partitioned_vector_local_view_iterator.hpp
index 391ca375f902..53fa4da079b7 100644
--- a/components/containers/partitioned_vector/include/hpx/components/containers/partitioned_vector/partitioned_vector_local_view_iterator.hpp
+++ b/components/containers/partitioned_vector/include/hpx/components/containers/partitioned_vector/partitioned_vector_local_view_iterator.hpp
@@ -49,12 +49,7 @@ namespace hpx {
         template <typename, typename>
         friend class const_partitioned_vector_local_view_iterator;
 
-        DataType& dereference()
-        {
-            HPX_ASSERT(!is_at_end());
-            return this->base_reference()->data();
-        }
-        DataType const& dereference() const
+        DataType& dereference() const
         {
             HPX_ASSERT(!is_at_end());
             return this->base_reference()->data();
diff --git a/components/containers/partitioned_vector/include/hpx/components/containers/partitioned_vector/partitioned_vector_segmented_iterator.hpp b/components/containers/partitioned_vector/include/hpx/components/containers/partitioned_vector/partitioned_vector_segmented_iterator.hpp
index 324fbab094d9..070e8378ae9f 100644
--- a/components/containers/partitioned_vector/include/hpx/components/containers/partitioned_vector/partitioned_vector_segmented_iterator.hpp
+++ b/components/containers/partitioned_vector/include/hpx/components/containers/partitioned_vector/partitioned_vector_segmented_iterator.hpp
@@ -765,13 +765,6 @@ namespace hpx::segmented {
         using local_iterator =
             typename partitioned_vector<T, Data>::local_iterator;
 
-        using const_segment_iterator =
-            typename partitioned_vector<T, Data>::const_segment_iterator;
-        using const_local_segment_iterator =
-            typename partitioned_vector<T, Data>::const_local_segment_iterator;
-        using const_local_iterator =
-            typename partitioned_vector<T, Data>::const_local_iterator;
-
         // constructors
         vector_iterator()
           : data_(nullptr)
@@ -1012,34 +1005,20 @@ namespace hpx::traits {
 
         //  This function should specify the local iterator which is at the
         //  beginning of the partition data.
-        static local_raw_iterator begin(local_segment_iterator& seg_iter)
+        static local_raw_iterator begin(local_segment_iterator const& seg_iter)
         {
             return local_raw_iterator(
                 seg_iter->begin(), seg_iter.base()->local_data_);
         }
 
-        static local_raw_const_iterator begin(
-            local_segment_iterator const& seg_iter)
-        {
-            return local_raw_const_iterator(
-                seg_iter->begin(), seg_iter.base()->local_data_);
-        }
-
         //  This function should specify the local iterator which is at the
         //  end of the partition data.
-        static local_raw_iterator end(local_segment_iterator& seg_iter)
+        static local_raw_iterator end(local_segment_iterator const& seg_iter)
         {
             return local_raw_iterator(
                 seg_iter->end(), seg_iter.base()->local_data_);
         }
 
-        static local_raw_const_iterator end(
-            local_segment_iterator const& seg_iter)
-        {
-            return local_raw_const_iterator(
-                seg_iter->end(), seg_iter.base()->local_data_);
-        }
-
         // Extract the base id for the segment referenced by the given segment
         // iterator.
         static id_type get_id(segment_iterator const& iter)
diff --git a/libs/core/algorithms/include/hpx/parallel/algorithms/for_loop_reduction.hpp b/libs/core/algorithms/include/hpx/parallel/algorithms/for_loop_reduction.hpp
index cb4490d7d7e5..171e5c5c969e 100644
--- a/libs/core/algorithms/include/hpx/parallel/algorithms/for_loop_reduction.hpp
+++ b/libs/core/algorithms/include/hpx/parallel/algorithms/for_loop_reduction.hpp
@@ -43,11 +43,7 @@ namespace hpx::parallel::detail {
         {
             std::size_t const cores =
                 hpx::parallel::execution::detail::get_os_thread_count();
-#if defined(HPX_HAVE_CXX17_SHARED_PTR_ARRAY)
-            data_ = std::make_shared<hpx::util::cache_line_data<T>[]>(cores);
-#else
             data_.reset(new hpx::util::cache_line_data<T>[cores]);
-#endif
             for (std::size_t i = 0; i != cores; ++i)
             {
                 data_[i].data_ = identity;
diff --git a/libs/core/algorithms/include/hpx/parallel/datapar/iterator_helpers.hpp b/libs/core/algorithms/include/hpx/parallel/datapar/iterator_helpers.hpp
index 2cff8d0e8136..fc9c73e02ed5 100644
--- a/libs/core/algorithms/include/hpx/parallel/datapar/iterator_helpers.hpp
+++ b/libs/core/algorithms/include/hpx/parallel/datapar/iterator_helpers.hpp
@@ -32,7 +32,8 @@ namespace hpx::parallel::util::detail {
     {
         static HPX_FORCEINLINE bool call(Iter& it) noexcept
         {
-            using value_type = typename std::iterator_traits<Iter>::value_type;
+            using value_type = typename std::iterator_traits<
+                std::remove_const_t<Iter>>::value_type;
             using pack_type = traits::vector_pack_type_t<value_type>;
 
             return (reinterpret_cast<std::uintptr_t>(std::addressof(*it)) &
diff --git a/libs/core/algorithms/include/hpx/parallel/datapar/zip_iterator.hpp b/libs/core/algorithms/include/hpx/parallel/datapar/zip_iterator.hpp
index 56307506ff5e..5f3f0ac04ab2 100644
--- a/libs/core/algorithms/include/hpx/parallel/datapar/zip_iterator.hpp
+++ b/libs/core/algorithms/include/hpx/parallel/datapar/zip_iterator.hpp
@@ -40,20 +40,6 @@ namespace hpx::parallel::util::detail {
         {
             return call(it, hpx::util::make_index_pack_t<sizeof...(Iter)>());
         }
-
-        template <std::size_t... Is>
-        static HPX_FORCEINLINE constexpr bool call(
-            hpx::util::zip_iterator<Iter...>& it, hpx::util::index_pack<Is...>)
-        {
-            auto& t = it.get_iterator_tuple();
-            return (true && ... && is_data_aligned(hpx::get<Is>(t)));
-        }
-
-        static HPX_FORCEINLINE constexpr bool call(
-            hpx::util::zip_iterator<Iter...>& it)
-        {
-            return call(it, hpx::util::make_index_pack_t<sizeof...(Iter)>());
-        }
     };
 
     ///////////////////////////////////////////////////////////////////////////
@@ -94,28 +80,6 @@ namespace hpx::parallel::traits {
                     typename std::iterator_traits<Iter>::value_type>::
                     unaligned(hpx::get<Is>(t))...);
         }
-
-        template <typename Tuple, typename... Iter, std::size_t... Is>
-        constexpr Tuple aligned_pack(hpx::util::zip_iterator<Iter...>& iter,
-            hpx::util::index_pack<Is...>)
-        {
-            auto& t = iter.get_iterator_tuple();
-            return hpx::make_tuple(
-                vector_pack_load<hpx::tuple_element_t<Is, Tuple>,
-                    typename std::iterator_traits<Iter>::value_type>::
-                    aligned(hpx::get<Is>(t))...);
-        }
-
-        template <typename Tuple, typename... Iter, std::size_t... Is>
-        constexpr Tuple unaligned_pack(hpx::util::zip_iterator<Iter...>& iter,
-            hpx::util::index_pack<Is...>)
-        {
-            auto& t = iter.get_iterator_tuple();
-            return hpx::make_tuple(
-                vector_pack_load<hpx::tuple_element_t<Is, Tuple>,
-                    typename std::iterator_traits<Iter>::value_type>::
-                    unaligned(hpx::get<Is>(t))...);
-        }
     }    // namespace detail
 
     template <typename... Vector, typename ValueType>
@@ -138,22 +102,6 @@ namespace hpx::parallel::traits {
             return traits::detail::unaligned_pack<value_type>(
                 iter, hpx::util::make_index_pack_t<sizeof...(Iter)>());
         }
-
-        template <typename... Iter>
-        static constexpr value_type aligned(
-            hpx::util::zip_iterator<Iter...>& iter)
-        {
-            return traits::detail::aligned_pack<value_type>(
-                iter, hpx::util::make_index_pack_t<sizeof...(Iter)>());
-        }
-
-        template <typename... Iter>
-        static constexpr value_type unaligned(
-            hpx::util::zip_iterator<Iter...>& iter)
-        {
-            return traits::detail::unaligned_pack<value_type>(
-                iter, hpx::util::make_index_pack_t<sizeof...(Iter)>());
-        }
     };
 
     ///////////////////////////////////////////////////////////////////////////
@@ -182,30 +130,6 @@ namespace hpx::parallel::traits {
                     unaligned(hpx::get<Is>(value), hpx::get<Is>(t)),
                 ...);
         }
-
-        template <typename Tuple, typename... Iter, std::size_t... Is>
-        constexpr void aligned_pack(Tuple& value,
-            hpx::util::zip_iterator<Iter...>& iter,
-            hpx::util::index_pack<Is...>)
-        {
-            auto& t = iter.get_iterator_tuple();
-            (vector_pack_store<hpx::tuple_element_t<Is, Tuple>,
-                 typename std::iterator_traits<Iter>::value_type>::
-                    aligned(hpx::get<Is>(value), hpx::get<Is>(t)),
-                ...);
-        }
-
-        template <typename Tuple, typename... Iter, std::size_t... Is>
-        constexpr void unaligned_pack(Tuple& value,
-            hpx::util::zip_iterator<Iter...>& iter,
-            hpx::util::index_pack<Is...>)
-        {
-            auto& t = iter.get_iterator_tuple();
-            (vector_pack_store<hpx::tuple_element_t<Is, Tuple>,
-                 typename std::iterator_traits<Iter>::value_type>::
-                    unaligned(hpx::get<Is>(value), hpx::get<Is>(t)),
-                ...);
-        }
     }    // namespace detail
 
     template <typename... Vector, typename ValueType>
@@ -226,22 +150,6 @@ namespace hpx::parallel::traits {
             traits::detail::unaligned_pack(
                 value, iter, hpx::util::make_index_pack_t<sizeof...(Iter)>());
         }
-
-        template <typename V, typename... Iter>
-        static constexpr void aligned(
-            V& value, hpx::util::zip_iterator<Iter...>& iter)
-        {
-            traits::detail::aligned_pack(
-                value, iter, hpx::util::make_index_pack_t<sizeof...(Iter)>());
-        }
-
-        template <typename V, typename... Iter>
-        static constexpr void unaligned(
-            V& value, hpx::util::zip_iterator<Iter...>& iter)
-        {
-            traits::detail::unaligned_pack(
-                value, iter, hpx::util::make_index_pack_t<sizeof...(Iter)>());
-        }
     };
 }    // namespace hpx::parallel::traits
 
diff --git a/libs/core/iterator_support/include/hpx/iterator_support/counting_iterator.hpp b/libs/core/iterator_support/include/hpx/iterator_support/counting_iterator.hpp
index 8dc232f17541..0f0b8ef4244c 100644
--- a/libs/core/iterator_support/include/hpx/iterator_support/counting_iterator.hpp
+++ b/libs/core/iterator_support/include/hpx/iterator_support/counting_iterator.hpp
@@ -84,7 +84,7 @@ namespace hpx::util {
 
             using type = iterator_adaptor<counting_iterator<Incrementable,
                                               CategoryOrTraversal, Difference>,
-                Incrementable, Incrementable, traversal, Incrementable&,
+                Incrementable, Incrementable, traversal, Incrementable const&,
                 difference>;
         };
     }    // namespace detail
@@ -122,11 +122,6 @@ namespace hpx::util {
         {
             return this->base_reference();
         }
-
-        HPX_HOST_DEVICE constexpr typename base_type::reference dereference()
-        {
-            return this->base_reference();
-        }
     };
 
     template <typename Incrementable, typename CategoryOrTraversal,
@@ -180,12 +175,8 @@ namespace hpx::util {
                 static_cast<typename base_type::base_type>(n);
         }
 
-        HPX_HOST_DEVICE constexpr decltype(auto) dereference() const noexcept
-        {
-            return this->base_reference();
-        }
-
-        HPX_HOST_DEVICE constexpr decltype(auto) dereference() noexcept
+        HPX_HOST_DEVICE constexpr typename base_type::reference dereference()
+            const noexcept
         {
             return this->base_reference();
         }
diff --git a/libs/core/iterator_support/include/hpx/iterator_support/iterator_adaptor.hpp b/libs/core/iterator_support/include/hpx/iterator_support/iterator_adaptor.hpp
index ac453e6c07d7..f93524b8141a 100644
--- a/libs/core/iterator_support/include/hpx/iterator_support/iterator_adaptor.hpp
+++ b/libs/core/iterator_support/include/hpx/iterator_support/iterator_adaptor.hpp
@@ -143,24 +143,19 @@ namespace hpx::util {
             return iterator_;
         }
 
-        HPX_HOST_DEVICE HPX_FORCEINLINE constexpr Base& base() noexcept
-        {
-            return iterator_;
-        }
-
     protected:
         // for convenience in derived classes
         using iterator_adaptor_ = iterator_adaptor<Derived, Base, Value,
             Category, Reference, Difference, Pointer>;
 
         // lvalue access to the Base object for Derived
-        HPX_HOST_DEVICE HPX_FORCEINLINE Base& base_reference() noexcept
+        HPX_HOST_DEVICE HPX_FORCEINLINE constexpr Base const& base_reference()
+            const noexcept
         {
             return iterator_;
         }
 
-        HPX_HOST_DEVICE HPX_FORCEINLINE constexpr Base const& base_reference()
-            const noexcept
+        HPX_HOST_DEVICE HPX_FORCEINLINE Base& base_reference() noexcept
         {
             return iterator_;
         }
diff --git a/libs/core/iterator_support/include/hpx/iterator_support/iterator_facade.hpp b/libs/core/iterator_support/include/hpx/iterator_support/iterator_facade.hpp
index 5b8b45a3edde..9f519933fb09 100644
--- a/libs/core/iterator_support/include/hpx/iterator_support/iterator_facade.hpp
+++ b/libs/core/iterator_support/include/hpx/iterator_support/iterator_facade.hpp
@@ -14,7 +14,6 @@
 #pragma once
 
 #include <hpx/config.hpp>
-#include <hpx/datastructures/tuple.hpp>
 #include <hpx/iterator_support/traits/is_iterator.hpp>
 #include <hpx/type_support/equality.hpp>
 
@@ -62,23 +61,12 @@ namespace hpx::util {
             it.decrement();
         }
 
-        template <typename Reference, typename Iterator>
-        HPX_HOST_DEVICE HPX_FORCEINLINE static constexpr Reference dereference(
-            Iterator& it)
-#if !defined(HPX_MSVC)
-            // MSVC has issues with this
-            noexcept(noexcept(std::declval<Iterator&>().dereference()))
-#endif
-        {
-            return it.dereference();
-        }
-
         template <typename Reference, typename Iterator>
         HPX_HOST_DEVICE HPX_FORCEINLINE static constexpr Reference dereference(
             Iterator const& it)
 #if !defined(HPX_MSVC)
             // MSVC has issues with this
-            noexcept(noexcept(std::declval<Iterator const&>().dereference()))
+            noexcept(noexcept(std::declval<Iterator>().dereference()))
 #endif
         {
             return it.dereference();
@@ -117,18 +105,12 @@ namespace hpx::util {
                 {
                 }
 
-                HPX_HOST_DEVICE HPX_FORCEINLINE constexpr decltype(auto)
+                HPX_HOST_DEVICE HPX_FORCEINLINE constexpr Reference*
                 operator->() noexcept
                 {
                     return std::addressof(ref_);
                 }
 
-                HPX_HOST_DEVICE HPX_FORCEINLINE constexpr decltype(auto)
-                operator->() const noexcept
-                {
-                    return std::addressof(ref_);
-                }
-
                 Reference ref_;
             };
 
@@ -146,37 +128,13 @@ namespace hpx::util {
         {
             using type = T*;
 
-            HPX_HOST_DEVICE HPX_FORCEINLINE static constexpr decltype(auto)
-            call(T& x) noexcept
-            {
-                return std::addressof(x);
-            }
-        };
-
-        template <typename T>
-        struct arrow_dispatch<T const&>    // "real" references
-        {
-            using type = T const*;
-
-            HPX_HOST_DEVICE HPX_FORCEINLINE static constexpr decltype(auto)
-            call(T const& x) noexcept
+            HPX_HOST_DEVICE HPX_FORCEINLINE static constexpr type call(
+                T& x) noexcept
             {
                 return std::addressof(x);
             }
         };
 
-        template <typename T>
-        struct make_const_reference
-        {
-            using type = std::conditional_t<std::is_reference_v<T>,
-                std::add_lvalue_reference_t<
-                    std::add_const_t<std::remove_reference_t<T>>>,
-                std::add_const_t<T>>;
-        };
-
-        template <typename T>
-        using make_const_reference_t = typename make_const_reference<T>::type;
-
         template <typename T>
         using arrow_dispatch_t = typename arrow_dispatch<T>::type;
 
@@ -207,37 +165,20 @@ namespace hpx::util {
                 return *static_cast<Derived const*>(this);
             }
 
-            using const_reference = make_const_reference_t<Reference>;
-
         public:
-            //            HPX_HOST_DEVICE constexpr decltype(auto) operator*() noexcept(
-            //                noexcept(iterator_core_access::dereference<reference>(
-            //                    std::declval<Derived>())))
-            //            {
-            //                return iterator_core_access::dereference<reference>(
-            //                    this->derived());
-            //            }
-
             HPX_HOST_DEVICE constexpr decltype(auto) operator*() const
                 noexcept(noexcept(iterator_core_access::dereference<reference>(
-                    std::declval<Derived const>())))
+                    std::declval<Derived>())))
             {
                 return iterator_core_access::dereference<reference>(
                     this->derived());
             }
 
-            //            HPX_HOST_DEVICE constexpr decltype(auto) operator->() noexcept(
-            //                noexcept(iterator_core_access::dereference<reference>(
-            //                    std::declval<Derived>())))
-            //            {
-            //                return arrow_dispatch<Reference>::call(*this->derived());
-            //            }
-
-            HPX_HOST_DEVICE constexpr decltype(auto) operator->() const
+            HPX_HOST_DEVICE constexpr pointer operator->() const
                 noexcept(noexcept(iterator_core_access::dereference<reference>(
-                    std::declval<Derived const>())))
+                    std::declval<Derived>())))
             {
-                return arrow_dispatch<reference>::call(*this->derived());
+                return arrow_dispatch<Reference>::call(*this->derived());
             }
 
             HPX_HOST_DEVICE Derived& operator++() noexcept(noexcept(
@@ -309,8 +250,8 @@ namespace hpx::util {
             {
             }
 
-            HPX_HOST_DEVICE constexpr operator reference() noexcept(
-                noexcept(*std::declval<Iterator>()))
+            HPX_HOST_DEVICE constexpr operator reference() const
+                noexcept(noexcept(*std::declval<Iterator>()))
             {
                 return *iter_;
             }
diff --git a/libs/core/iterator_support/include/hpx/iterator_support/zip_iterator.hpp b/libs/core/iterator_support/include/hpx/iterator_support/zip_iterator.hpp
index 7dce86753bb9..b7c4f4784be6 100644
--- a/libs/core/iterator_support/include/hpx/iterator_support/zip_iterator.hpp
+++ b/libs/core/iterator_support/include/hpx/iterator_support/zip_iterator.hpp
@@ -124,15 +124,10 @@ namespace hpx::util {
         struct dereference_iterator<hpx::tuple<Ts...>>
         {
             template <std::size_t... Is>
-            HPX_HOST_DEVICE static constexpr decltype(auto) call(
-                util::index_pack<Is...>, hpx::tuple<Ts...>& iterators)
-            {
-                return hpx::forward_as_tuple(*hpx::get<Is>(iterators)...);
-            }
-
-            template <std::size_t... Is>
-            HPX_HOST_DEVICE static constexpr decltype(auto) call(
-                util::index_pack<Is...>, hpx::tuple<Ts...> const& iterators)
+            HPX_HOST_DEVICE static constexpr
+                typename zip_iterator_reference<hpx::tuple<Ts...>>::type
+                call(
+                    util::index_pack<Is...>, hpx::tuple<Ts...> const& iterators)
             {
                 return hpx::forward_as_tuple(*hpx::get<Is>(iterators)...);
             }
@@ -312,15 +307,8 @@ namespace hpx::util {
                 }
             }
 
-            HPX_HOST_DEVICE constexpr decltype(auto) dereference()
-            {
-                return dereference_iterator<IteratorTuple>::call(
-                    util::make_index_pack_t<
-                        hpx::tuple_size<IteratorTuple>::value>(),
-                    iterators_);
-            }
-
-            HPX_HOST_DEVICE constexpr decltype(auto) dereference() const
+            HPX_HOST_DEVICE constexpr typename base_type::reference
+            dereference() const
             {
                 return dereference_iterator<IteratorTuple>::call(
                     util::make_index_pack_t<
@@ -378,12 +366,6 @@ namespace hpx::util {
         private:
             IteratorTuple iterators_;
         };
-
-        template <typename... Ts>
-        struct make_const_reference<hpx::tuple<Ts...>>
-        {
-            using type = hpx::tuple<make_const_reference_t<Ts>...>;
-        };
     }    // namespace detail
 
     template <typename... Ts>
diff --git a/libs/core/program_options/include/hpx/program_options/eof_iterator.hpp b/libs/core/program_options/include/hpx/program_options/eof_iterator.hpp
index 6f3e294ae34e..c46887603ffd 100644
--- a/libs/core/program_options/include/hpx/program_options/eof_iterator.hpp
+++ b/libs/core/program_options/include/hpx/program_options/eof_iterator.hpp
@@ -80,11 +80,6 @@ namespace hpx { namespace program_options {
             return m_at_eof && other.m_at_eof;
         }
 
-        ValueType& dereference() noexcept
-        {
-            return m_value;
-        }
-
         ValueType const& dereference() const noexcept
         {
             return m_value;
diff --git a/libs/full/collectives/include/hpx/collectives/gather.hpp b/libs/full/collectives/include/hpx/collectives/gather.hpp
index 5931f2deb1d2..537dc92cc95c 100644
--- a/libs/full/collectives/include/hpx/collectives/gather.hpp
+++ b/libs/full/collectives/include/hpx/collectives/gather.hpp
@@ -470,8 +470,8 @@ namespace hpx::collectives {
         root_site_arg root_site = root_site_arg())
     {
         HPX_ASSERT(this_site != root_site);
-        gather_there(create_communicator(basename, num_sites_arg(),
-                                this_site, generation, root_site),
+        gather_there(create_communicator(basename, num_sites_arg(), this_site,
+                         generation, root_site),
             HPX_FORWARD(T, local_result), this_site)
             .get();
     }