entity:

* small changes to the entt_traits class
* natvis snippets for basic_sparse_set and basic_storage (with tombstone detection)

natvis/entt/entity.natvis

@@ -1,3 +1,27 @@
 <?xml version="1.0" encoding="utf-8"?>
 <AutoVisualizer xmlns="http://schemas.microsoft.com/vstudio/debugger/natvis/2010">
+	<Type Name="entt::basic_sparse_set&lt;*&gt;">
+		<DisplayString>{{ size={ packed.size() } }}</DisplayString>
+		<Expand>
+			<Item Name="[capacity]">packed.capacity()</Item>
+			<IndexListItems Optional="true" Condition="packed.size() != 0">
+				<Size>packed.size()</Size>
+				<ValueNode Condition="packed[$i] &lt; (entity_traits::reserved &amp; ~entity_traits::entity_mask)">packed[$i]</ValueNode>
+				<ValueNode>tombstone</ValueNode>
+			</IndexListItems>
+		</Expand>
+	</Type>
+	<Type Name="entt::basic_storage&lt;*&gt;">
+		<DisplayString>{{ size={ base_type::packed.size() } }}</DisplayString>
+		<Expand>
+			<Item Name="[capacity]" Optional="true">packed.first_base::value.capacity() * packed_page_v</Item>
+			<Item Name="[page size]" Optional="true">packed_page_v</Item>
+			<Item Name="[entities]">(base_type*)this,nd</Item>
+			<IndexListItems Optional="true" Condition="base_type::packed.size() != 0">
+				<Size>base_type::packed.size()</Size>
+				<ValueNode Condition="base_type::packed[$i] &lt; (entity_traits::reserved &amp; ~entity_traits::entity_mask)">packed.first_base::value[$i / packed_page_v][$i &amp; (packed_page_v - 1)]</ValueNode>
+				<ValueNode>tombstone</ValueNode>
+			</IndexListItems>
+		</Expand>
+	</Type>
 </AutoVisualizer>

src/entt/entity/entity.hpp

@@ -59,18 +59,18 @@ struct entt_traits<std::uint64_t> {
  * @tparam Type Type of identifier.
  */
 template<typename Type>
-class entt_traits {
-    using entity_traits = internal::entt_traits<Type>;
+class entt_traits: private internal::entt_traits<Type> {
+    using base_type = internal::entt_traits<Type>;
 
 public:
     /*! @brief Value type. */
     using value_type = Type;
     /*! @brief Underlying entity type. */
-    using entity_type = typename entity_traits::entity_type;
+    using entity_type = typename base_type::entity_type;
     /*! @brief Underlying version type. */
-    using version_type = typename entity_traits::version_type;
+    using version_type = typename base_type::version_type;
     /*! @brief Reserved identifier. */
-    static constexpr entity_type reserved = entity_traits::entity_mask | (entity_traits::version_mask << entity_traits::entity_shift);
+    static constexpr entity_type reserved = base_type::entity_mask | (base_type::version_mask << base_type::entity_shift);
 
     /**
      * @brief Converts an entity to its underlying type.
@@ -87,7 +87,7 @@ public:
      * @return The integral representation of the entity part.
      */
     [[nodiscard]] static constexpr entity_type to_entity(const value_type value) ENTT_NOEXCEPT {
-        return (to_integral(value) & entity_traits::entity_mask);
+        return (to_integral(value) & base_type::entity_mask);
     }
 
     /**
@@ -96,8 +96,8 @@ public:
      * @return The integral representation of the version part.
      */
     [[nodiscard]] static constexpr version_type to_version(const value_type value) ENTT_NOEXCEPT {
-        constexpr auto version_mask = (entity_traits::version_mask << entity_traits::entity_shift);
-        return ((to_integral(value) & version_mask) >> entity_traits::entity_shift);
+        constexpr auto version_mask = (base_type::version_mask << base_type::entity_shift);
+        return ((to_integral(value) & version_mask) >> base_type::entity_shift);
     }
 
     /**
@@ -111,7 +111,7 @@ public:
      * @return A properly constructed identifier.
      */
     [[nodiscard]] static constexpr value_type construct(const entity_type entity, const version_type version) ENTT_NOEXCEPT {
-        return value_type{(entity & entity_traits::entity_mask) | (static_cast<entity_type>(version) << entity_traits::entity_shift)};
+        return value_type{(entity & base_type::entity_mask) | (static_cast<entity_type>(version) << base_type::entity_shift)};
     }
 
     /**
@@ -125,8 +125,8 @@ public:
      * @return A properly constructed identifier.
      */
     [[nodiscard]] static constexpr value_type combine(const entity_type lhs, const entity_type rhs) ENTT_NOEXCEPT {
-        constexpr auto version_mask = (entity_traits::version_mask << entity_traits::entity_shift);
-        return value_type{(lhs & entity_traits::entity_mask) | (rhs & version_mask)};
+        constexpr auto version_mask = (base_type::version_mask << base_type::entity_shift);
+        return value_type{(lhs & base_type::entity_mask) | (rhs & version_mask)};
     }
 };