meta_range: iterator review

src/entt/meta/range.hpp

@@ -7,60 +7,80 @@
 
 namespace entt {
 
+/**
+ * @cond TURN_OFF_DOXYGEN
+ * Internal details not to be documented.
+ */
+
+namespace internal {
+
+template<typename Type, typename Node>
+struct meta_range_iterator {
+    using difference_type = std::ptrdiff_t;
+    using value_type = Type;
+    using pointer = input_iterator_pointer<value_type>;
+    using reference = value_type;
+    using iterator_category = std::input_iterator_tag;
+    using node_type = Node;
+
+    meta_range_iterator() ENTT_NOEXCEPT = default;
+
+    meta_range_iterator(node_type *head) ENTT_NOEXCEPT
+        : it{head} {}
+
+    meta_range_iterator &operator++() ENTT_NOEXCEPT {
+        return (it = it->next), *this;
+    }
+
+    meta_range_iterator operator++(int) ENTT_NOEXCEPT {
+        meta_range_iterator orig = *this;
+        return ++(*this), orig;
+    }
+
+    [[nodiscard]] reference operator*() const ENTT_NOEXCEPT {
+        return it;
+    }
+
+    [[nodiscard]] pointer operator->() const ENTT_NOEXCEPT {
+        return operator*();
+    }
+
+    [[nodiscard]] const node_type *base() const ENTT_NOEXCEPT {
+        return it;
+    }
+
+private:
+    node_type *it{};
+};
+
+template<typename Type, typename Node>
+[[nodiscard]] bool operator==(const meta_range_iterator<Type, Node> &lhs, const meta_range_iterator<Type, Node> &rhs) ENTT_NOEXCEPT {
+    return lhs.base() == rhs.base();
+}
+
+template<typename Type, typename Node>
+[[nodiscard]] bool operator!=(const meta_range_iterator<Type, Node> &lhs, const meta_range_iterator<Type, Node> &rhs) ENTT_NOEXCEPT {
+    return !(lhs == rhs);
+}
+
+} // namespace internal
+
+/**
+ * Internal details not to be documented.
+ * @endcond
+ */
+
 /**
  * @brief Iterable range to use to iterate all types of meta objects.
  * @tparam Type Type of meta objects returned.
  * @tparam Node Type of meta nodes iterated.
  */
 template<typename Type, typename Node = typename Type::node_type>
-class meta_range {
-    struct range_iterator {
-        using difference_type = std::ptrdiff_t;
-        using value_type = Type;
-        using pointer = input_iterator_pointer<value_type>;
-        using reference = value_type;
-        using iterator_category = std::input_iterator_tag;
-        using node_type = Node;
-
-        range_iterator() ENTT_NOEXCEPT = default;
-
-        range_iterator(node_type *head) ENTT_NOEXCEPT
-            : it{head} {}
-
-        range_iterator &operator++() ENTT_NOEXCEPT {
-            return (it = it->next), *this;
-        }
-
-        range_iterator operator++(int) ENTT_NOEXCEPT {
-            range_iterator orig = *this;
-            return ++(*this), orig;
-        }
-
-        [[nodiscard]] reference operator*() const ENTT_NOEXCEPT {
-            return it;
-        }
-
-        [[nodiscard]] pointer operator->() const ENTT_NOEXCEPT {
-            return operator*();
-        }
-
-        [[nodiscard]] bool operator==(const range_iterator &other) const ENTT_NOEXCEPT {
-            return other.it == it;
-        }
-
-        [[nodiscard]] bool operator!=(const range_iterator &other) const ENTT_NOEXCEPT {
-            return !(*this == other);
-        }
-
-    private:
-        node_type *it{};
-    };
-
-public:
+struct meta_range {
     /*! @brief Node type. */
     using node_type = Node;
     /*! @brief Input iterator type. */
-    using iterator = range_iterator;
+    using iterator = internal::meta_range_iterator<Type, Node>;
     /*! @brief Constant input iterator type. */
     using const_iterator = iterator;
 

test/entt/meta/meta_range.cpp

@@ -52,4 +52,7 @@ TEST_F(MetaRange, IteratorConversion) {
 
     ASSERT_EQ(*it, entt::resolve<double>());
     ASSERT_EQ(*it, *cit);
+
+    ASSERT_EQ(it, cit);
+    ASSERT_NE(++cit, it);
 }