diff --git a/include/xo/arena/DArenaHashMap.hpp b/include/xo/arena/DArenaHashMap.hpp
index 75b2f95..63741e6 100644
--- a/include/xo/arena/DArenaHashMap.hpp
+++ b/include/xo/arena/DArenaHashMap.hpp
@@ -8,6 +8,7 @@
 #include "DArenaVector.hpp"
 #include "hashmap/verify_policy.hpp"
 #include "hashmap/HashMapStore.hpp"
+#include "hashmap/DArenaHashMapIterator.hpp"
 #include <xo/indentlog/scope.hpp>
 #include <algorithm>
 #include <array>
@@ -25,74 +26,6 @@ namespace xo {
         };
 #endif
 
-        namespace detail {
-
-            template <typename Key,
-                      typename Value>
-            struct DArenaHashMapIterator : public DArenaHashMapUtil {
-                using value_type = std::pair<const Key, Value>;
-
-            public:
-                DArenaHashMapIterator(uint8_t * c, value_type * p)
-                    : ctrl_{c}, pos_{p} {}
-
-                value_type & operator*() const { return *pos_; }
-                value_type * operator->() const { return pos_; }
-
-                /** true iff iterator at sentinel position (not dereferencable state !) **/
-                bool _at_slot_sentinel() const { return is_sentinel(*ctrl_) && (*ctrl_ != c_iterator_bookend); }
-
-                bool operator==(const DArenaHashMapIterator & x) const {
-                    return this->pos_ == x.pos_;
-                }
-
-                bool operator!=(const DArenaHashMapIterator & x) const {
-                    return this->pos_ != x.pos_;
-                }
-
-                DArenaHashMapIterator & operator++() {
-                    do {
-                        ++ctrl_;
-                        ++pos_;
-
-                        /** end condition: iterator ends at last non-wrapped position.
-                         *  relyin on bookend sentinel values at known offset from 'wrap' section
-                         *
-                         *                                        ctrl_       ctrl_ + c_group_size
-                         *                                            |       |
-                         *                                            v       v
-                         *   <----------------- control_size(n_slot) ---------------->
-                         *   <-stub-> <----------- n_slot ----------> <group> <-stub->
-                         *  +--------+-------------------------------+-------+--------+
-                         *  | 0xF0   | empty / data / tombstone      | wrap  | 0xF0   |
-                         *  +--------+-------------------------------+-------+--------+
-                         **/
-                    } while (is_sentinel(*ctrl_)
-                             && (*(ctrl_ + c_group_size) != c_iterator_bookend));
-
-                    return *this;
-                }
-
-                DArenaHashMapIterator & operator--() {
-                    /* simpler than forward iteration, since bookend immediately
-                     * precedes control byte for first slot
-                     */
-                    do {
-                        --ctrl_;
-                        --pos_;
-                    } while (is_sentinel(*ctrl_)
-                             && (*ctrl_ != c_iterator_bookend));
-
-                    return *this;
-                }
-
-            private:
-                uint8_t * ctrl_ = nullptr;
-                value_type * pos_ = nullptr;
-            };
-
-        }
-
         /** @brief flat hash map of key-value pairs using dedicated DArenas for storage
          *
          *  Replicates (to the extent feasible) std::unordered_map<K,V>
diff --git a/include/xo/arena/hashmap/DArenaHashMapIterator.hpp b/include/xo/arena/hashmap/DArenaHashMapIterator.hpp
new file mode 100644
index 0000000..285e449
--- /dev/null
+++ b/include/xo/arena/hashmap/DArenaHashMapIterator.hpp
@@ -0,0 +1,82 @@
+/** @file DArenaHashMapIterator.hpp
+*
+ *  @author Roland Conybeare, Jan 2026
+ **/
+
+#pragma once
+
+#include "hashmap/DArenaHashMapUtil.hpp"
+
+namespace xo {
+    namespace mm {
+        namespace detail {
+
+            template <typename Key,
+                      typename Value>
+            struct DArenaHashMapIterator : public DArenaHashMapUtil {
+                using value_type = std::pair<const Key, Value>;
+
+            public:
+                DArenaHashMapIterator(uint8_t * c, value_type * p)
+                    : ctrl_{c}, pos_{p} {}
+
+                value_type & operator*() const { return *pos_; }
+                value_type * operator->() const { return pos_; }
+
+                /** true iff iterator at sentinel position (not dereferencable state !) **/
+                bool _at_slot_sentinel() const { return is_sentinel(*ctrl_) && (*ctrl_ != c_iterator_bookend); }
+
+                bool operator==(const DArenaHashMapIterator & x) const {
+                    return this->pos_ == x.pos_;
+                }
+
+                bool operator!=(const DArenaHashMapIterator & x) const {
+                    return this->pos_ != x.pos_;
+                }
+
+                DArenaHashMapIterator & operator++() {
+                    do {
+                        ++ctrl_;
+                        ++pos_;
+
+                        /** end condition: iterator ends at last non-wrapped position.
+                         *  relyin on bookend sentinel values at known offset from 'wrap' section
+                         *
+                         *                                        ctrl_       ctrl_ + c_group_size
+                         *                                            |       |
+                         *                                            v       v
+                         *   <----------------- control_size(n_slot) ---------------->
+                         *   <-stub-> <----------- n_slot ----------> <group> <-stub->
+                         *  +--------+-------------------------------+-------+--------+
+                         *  | 0xF0   | empty / data / tombstone      | wrap  | 0xF0   |
+                         *  +--------+-------------------------------+-------+--------+
+                         **/
+                    } while (is_sentinel(*ctrl_)
+                             && (*(ctrl_ + c_group_size) != c_iterator_bookend));
+
+                    return *this;
+                }
+
+                DArenaHashMapIterator & operator--() {
+                    /* simpler than forward iteration, since bookend immediately
+                     * precedes control byte for first slot
+                     */
+                    do {
+                        --ctrl_;
+                        --pos_;
+                    } while (is_sentinel(*ctrl_)
+                             && (*ctrl_ != c_iterator_bookend));
+
+                    return *this;
+                }
+
+            private:
+                uint8_t * ctrl_ = nullptr;
+                value_type * pos_ = nullptr;
+            };
+
+        }
+    } /*namespace mm*/
+} /*namespace xo*/
+
+/* end DArenaHashMapIterator.hpp */