basic_registry:

* added fast path to destroy
* added fast path to remove
* added fast path to erase
* minor changes

src/entt/entity/registry.hpp

@@ -45,13 +45,14 @@ template<typename Entity>
 class basic_registry {
     using traits_type = entt_traits<Entity>;
     using poly_storage_type = typename poly_storage_traits<Entity>::storage_type;
+    using basic_common_type = basic_sparse_set<Entity>;
 
     template<typename Component>
     using storage_type = constness_as_t<typename storage_traits<Entity, std::remove_const_t<Component>>::storage_type, Component>;
 
     struct pool_data {
         poly_storage_type poly;
-        std::unique_ptr<basic_sparse_set<Entity>> pool{};
+        std::unique_ptr<basic_common_type> pool{};
     };
 
     template<typename...>
@@ -61,7 +62,7 @@ class basic_registry {
     struct group_handler<exclude_t<Exclude...>, get_t<Get...>, Owned...> {
         static_assert(!std::disjunction_v<typename component_traits<Owned>::in_place_delete...>, "Groups do not support in-place delete");
         static_assert(std::conjunction_v<std::is_same<Owned, std::remove_const_t<Owned>>..., std::is_same<Get, std::remove_const_t<Get>>..., std::is_same<Exclude, std::remove_const_t<Exclude>>...>, "One or more component types are invalid");
-        std::conditional_t<sizeof...(Owned) == 0, basic_sparse_set<Entity>, std::size_t> current{};
+        std::conditional_t<sizeof...(Owned) == 0, basic_common_type, std::size_t> current{};
 
         template<typename Component>
         void maybe_valid_if(basic_registry &owner, const Entity entt) {
@@ -140,10 +141,10 @@ class basic_registry {
     }
 
     auto release_entity(const Entity entity, const typename traits_type::version_type version) {
-        const auto entt = traits_type::to_entity(entity);
-        entities[entt] = traits_type::construct(traits_type::to_entity(free_list), version + (version == traits_type::to_version(tombstone)));
+        const auto vers = version + (version == traits_type::to_version(tombstone));
+        entities[traits_type::to_entity(entity)] = traits_type::construct(traits_type::to_entity(free_list), vers);
         free_list = (tombstone | entity);
-        return traits_type::to_version(entities[entt]);
+        return vers;
     }
 
 public:
@@ -562,8 +563,8 @@ public:
     version_type destroy(const entity_type entity, const version_type version) {
         ENTT_ASSERT(valid(entity), "Invalid entity");
 
-        for(auto pos = pools.size(); pos; --pos) {
-            pools[pos-1].pool && pools[pos-1].pool->remove(entity, this);
+        for(auto &&pdata: pools) {
+            pdata.pool && pdata.pool->remove(entity, this);
         }
 
         return release_entity(entity, version);
@@ -580,8 +581,16 @@ public:
      */
     template<typename It>
     void destroy(It first, It last) {
-        for(; first != last; ++first) {
-            destroy(*first, version(*first) + 1u);
+        if constexpr(is_iterator_type_v<typename basic_common_type::iterator, It>) {
+            for(; first != last; ++first) {
+                destroy(*first, version(*first) + 1u);
+            }
+        } else {
+            for(auto &&pdata: pools) {
+                pdata.pool && pdata.pool->remove(first, last, this);
+            }
+
+            release(first, last);
         }
     }
 
@@ -756,10 +765,19 @@ public:
      */
     template<typename... Component, typename It>
     size_type remove(It first, It last) {
+        static_assert(sizeof...(Component) > 0, "Provide one or more component types");
+        const auto cpools = std::make_tuple(assure<Component>()...);
         size_type count{};
 
-        for(; first != last; ++first) {
-            count += remove<Component...>(*first);
+        if constexpr(is_iterator_type_v<typename basic_common_type::iterator, It>) {
+            for(; first != last; ++first) {
+                const auto entity = *first;
+                ENTT_ASSERT(valid(entity), "Invalid entity");
+                count += (std::get<storage_type<Component> *>(cpools)->remove(entity, this) + ...);
+            }
+        } else {
+            ENTT_ASSERT(std::all_of(first, last, [this](const auto entity) { return valid(entity); }), "Invalid entity");
+            count += (std::get<storage_type<Component> *>(cpools)->remove(first, last, this) + ...);
         }
 
         return count;
@@ -794,8 +812,18 @@ public:
      */
     template<typename... Component, typename It>
     void erase(It first, It last) {
-        for(; first != last; ++first) {
-            erase<Component...>(*first);
+        static_assert(sizeof...(Component) > 0, "Provide one or more component types");
+        const auto cpools = std::make_tuple(assure<Component>()...);
+
+        if constexpr(is_iterator_type_v<typename basic_common_type::iterator, It>) {
+            for(; first != last; ++first) {
+                const auto entity = *first;
+                ENTT_ASSERT(valid(entity), "Invalid entity");
+                (std::get<storage_type<Component> *>(cpools)->erase(entity, this), ...);
+            }
+        } else {
+            ENTT_ASSERT(std::all_of(first, last, [this](const auto entity) { return valid(entity); }), "Invalid entity");
+            (std::get<storage_type<Component> *>(cpools)->erase(first, last, this), ...);
         }
     }
 
@@ -807,10 +835,8 @@ public:
     template<typename... Component>
     void compact() {
         if constexpr(sizeof...(Component) == 0) {
-            for(auto pos = pools.size(); pos; --pos) {
-                if(auto &pdata = pools[pos-1]; pdata.pool) {
-                    pdata.pool->compact();
-                }
+            for(auto &&pdata: pools) {
+                pdata.pool && (pdata.pool->compact(), true);
             }
         } else {
             (assure<Component>()->compact(), ...);
@@ -842,8 +868,8 @@ public:
     void remove_all(const entity_type entity) {
         ENTT_ASSERT(valid(entity), "Invalid entity");
 
-        for(auto pos = pools.size(); pos; --pos) {
-            pools[pos-1].pool && pools[pos-1].pool->remove(entity, this);
+        for(auto &&pdata: pools) {
+            pdata.pool && pdata.pool->remove(entity, this);
         }
     }
 
@@ -989,10 +1015,8 @@ public:
     template<typename... Component>
     void clear() {
         if constexpr(sizeof...(Component) == 0) {
-            for(auto pos = pools.size(); pos; --pos) {
-                if(auto &pdata = pools[pos-1]; pdata.pool) {
-                    pdata.pool->clear(this);
-                }
+            for(auto &&pdata: pools) {
+                pdata.pool && (pdata.pool->clear(this), true);
             }
 
             each([this](const auto entity) { release_entity(entity, version(entity) + 1u); });
@@ -1216,8 +1240,8 @@ public:
      */
     template<typename ItComp, typename ItExcl = id_type *>
     [[nodiscard]] basic_runtime_view<Entity> runtime_view(ItComp first, ItComp last, ItExcl from = {}, ItExcl to = {}) const {
-        std::vector<const basic_sparse_set<Entity> *> component(std::distance(first, last));
-        std::vector<const basic_sparse_set<Entity> *> filter(std::distance(from, to));
+        std::vector<const basic_common_type *> component(std::distance(first, last));
+        std::vector<const basic_common_type *> filter(std::distance(from, to));
 
         std::transform(first, last, component.begin(), [this](const auto ctype) {
             const auto it = std::find_if(pools.cbegin(), pools.cend(), [ctype](auto &&pdata) { return pdata.poly && pdata.poly->value_type().hash() == ctype; });

test/entt/entity/registry.cpp

@@ -539,29 +539,29 @@ TEST(Registry, RangeDestroy) {
     entt::registry registry;
     const auto iview = registry.view<int>();
     const auto icview = registry.view<int, char>();
+    entt::entity entities[3u];
 
-    const auto e0 = registry.create();
-    const auto e1 = registry.create();
-    const auto e2 = registry.create();
+    registry.create(std::begin(entities), std::end(entities));
 
-    registry.emplace<int>(e0);
-    registry.emplace<char>(e0);
-    registry.emplace<double>(e0);
+    registry.emplace<int>(entities[0u]);
+    registry.emplace<char>(entities[0u]);
+    registry.emplace<double>(entities[0u]);
 
-    registry.emplace<int>(e1);
-    registry.emplace<char>(e1);
+    registry.emplace<int>(entities[1u]);
+    registry.emplace<char>(entities[1u]);
 
-    registry.emplace<int>(e2);
+    registry.emplace<int>(entities[2u]);
 
-    ASSERT_TRUE(registry.valid(e0));
-    ASSERT_TRUE(registry.valid(e1));
-    ASSERT_TRUE(registry.valid(e2));
+    ASSERT_TRUE(registry.valid(entities[0u]));
+    ASSERT_TRUE(registry.valid(entities[1u]));
+    ASSERT_TRUE(registry.valid(entities[2u]));
 
     registry.destroy(icview.begin(), icview.end());
+    registry.destroy(icview.rbegin(), icview.rend());
 
-    ASSERT_FALSE(registry.valid(e0));
-    ASSERT_FALSE(registry.valid(e1));
-    ASSERT_TRUE(registry.valid(e2));
+    ASSERT_FALSE(registry.valid(entities[0u]));
+    ASSERT_FALSE(registry.valid(entities[1u]));
+    ASSERT_TRUE(registry.valid(entities[2u]));
 
     ASSERT_EQ(registry.size<int>(), 1u);
     ASSERT_EQ(registry.size<char>(), 0u);
@@ -569,43 +569,57 @@ TEST(Registry, RangeDestroy) {
 
     registry.destroy(iview.begin(), iview.end());
 
-    ASSERT_FALSE(registry.valid(e2));
-    ASSERT_NO_FATAL_FAILURE(registry.destroy(iview.begin(), iview.end()));
+    ASSERT_FALSE(registry.valid(entities[2u]));
+    ASSERT_NO_FATAL_FAILURE(registry.destroy(iview.rbegin(), iview.rend()));
     ASSERT_EQ(iview.size(), 0u);
     ASSERT_EQ(icview.size_hint(), 0u);
 
     ASSERT_EQ(registry.size<int>(), 0u);
     ASSERT_EQ(registry.size<char>(), 0u);
     ASSERT_EQ(registry.size<double>(), 0u);
+
+    registry.create(std::begin(entities), std::end(entities));
+    registry.insert<int>(std::begin(entities), std::end(entities));
+
+    ASSERT_TRUE(registry.valid(entities[0u]));
+    ASSERT_TRUE(registry.valid(entities[1u]));
+    ASSERT_TRUE(registry.valid(entities[2u]));
+    ASSERT_EQ(registry.size<int>(), 3u);
+
+    registry.destroy(std::begin(entities), std::end(entities));
+
+    ASSERT_FALSE(registry.valid(entities[0u]));
+    ASSERT_FALSE(registry.valid(entities[1u]));
+    ASSERT_FALSE(registry.valid(entities[2u]));
+    ASSERT_EQ(registry.size<int>(), 0u);
 }
 
 TEST(Registry, StableDestroy) {
     entt::registry registry;
     const auto iview = registry.view<int>();
     const auto icview = registry.view<int, stable_type>();
+    entt::entity entities[3u];
 
-    const auto e0 = registry.create();
-    const auto e1 = registry.create();
-    const auto e2 = registry.create();
+    registry.create(std::begin(entities), std::end(entities));
 
-    registry.emplace<int>(e0);
-    registry.emplace<stable_type>(e0);
-    registry.emplace<double>(e0);
+    registry.emplace<int>(entities[0u]);
+    registry.emplace<stable_type>(entities[0u]);
+    registry.emplace<double>(entities[0u]);
 
-    registry.emplace<int>(e1);
-    registry.emplace<stable_type>(e1);
+    registry.emplace<int>(entities[1u]);
+    registry.emplace<stable_type>(entities[1u]);
 
-    registry.emplace<int>(e2);
+    registry.emplace<int>(entities[2u]);
 
-    ASSERT_TRUE(registry.valid(e0));
-    ASSERT_TRUE(registry.valid(e1));
-    ASSERT_TRUE(registry.valid(e2));
+    ASSERT_TRUE(registry.valid(entities[0u]));
+    ASSERT_TRUE(registry.valid(entities[1u]));
+    ASSERT_TRUE(registry.valid(entities[2u]));
 
     registry.destroy(icview.begin(), icview.end());
 
-    ASSERT_FALSE(registry.valid(e0));
-    ASSERT_FALSE(registry.valid(e1));
-    ASSERT_TRUE(registry.valid(e2));
+    ASSERT_FALSE(registry.valid(entities[0u]));
+    ASSERT_FALSE(registry.valid(entities[1u]));
+    ASSERT_TRUE(registry.valid(entities[2u]));
 
     ASSERT_EQ(registry.size<int>(), 1u);
     ASSERT_EQ(registry.size<stable_type>(), 2u);
@@ -613,7 +627,7 @@ TEST(Registry, StableDestroy) {
 
     registry.destroy(iview.begin(), iview.end());
 
-    ASSERT_FALSE(registry.valid(e2));
+    ASSERT_FALSE(registry.valid(entities[2u]));
     ASSERT_EQ(iview.size(), 0u);
     ASSERT_EQ(icview.size_hint(), 0u);
 
@@ -624,20 +638,20 @@ TEST(Registry, StableDestroy) {
 
 TEST(Registry, ReleaseVersion) {
     entt::registry registry;
+    entt::entity entities[2u];
 
-    const auto e0 = registry.create();
-    const auto e1 = registry.create();
+    registry.create(std::begin(entities), std::end(entities));
 
-    ASSERT_EQ(registry.current(e0), entt::registry::version_type{});
-    ASSERT_EQ(registry.current(e1), entt::registry::version_type{});
+    ASSERT_EQ(registry.current(entities[0u]), entt::registry::version_type{});
+    ASSERT_EQ(registry.current(entities[1u]), entt::registry::version_type{});
 
-    registry.release(e0);
-    registry.release(e1, 3);
+    registry.release(entities[0u]);
+    registry.release(entities[1u], 3);
 
-    ASSERT_DEATH(registry.release(e0), "");
-    ASSERT_DEATH(registry.release(e1, 3), "");
-    ASSERT_EQ(registry.current(e0), entt::registry::version_type{1});
-    ASSERT_EQ(registry.current(e1), entt::registry::version_type{3});
+    ASSERT_DEATH(registry.release(entities[0u]), "");
+    ASSERT_DEATH(registry.release(entities[1u], 3), "");
+    ASSERT_EQ(registry.current(entities[0u]), entt::registry::version_type{1});
+    ASSERT_EQ(registry.current(entities[1u]), entt::registry::version_type{3});
 }
 
 TEST(Registry, RangeRelease) {
@@ -789,17 +803,17 @@ TEST(Registry, View) {
     auto mview = registry.view<int, char>();
     auto iview = registry.view<int>();
     auto cview = registry.view<char>();
+    entt::entity entities[3u];
 
-    const auto e0 = registry.create();
-    registry.emplace<int>(e0, 0);
-    registry.emplace<char>(e0, 'c');
+    registry.create(std::begin(entities), std::end(entities));
 
-    const auto e1 = registry.create();
-    registry.emplace<int>(e1, 0);
+    registry.emplace<int>(entities[0u], 0);
+    registry.emplace<char>(entities[0u], 'c');
 
-    const auto e2 = registry.create();
-    registry.emplace<int>(e2, 0);
-    registry.emplace<char>(e2, 'c');
+    registry.emplace<int>(entities[1u], 0);
+
+    registry.emplace<int>(entities[2u], 0);
+    registry.emplace<char>(entities[2u], 'c');
 
     ASSERT_EQ(iview.size(), 3u);
     ASSERT_EQ(cview.size(), 2u);
@@ -1245,6 +1259,7 @@ TEST(Registry, ConstructWithComponents) {
 
 TEST(Registry, Signals) {
     entt::registry registry;
+    entt::entity entities[2u];
     listener listener;
 
     registry.on_construct<empty_type>().connect<&listener::incr<empty_type>>(listener);
@@ -1252,138 +1267,126 @@ TEST(Registry, Signals) {
     registry.on_construct<int>().connect<&listener::incr<int>>(listener);
     registry.on_destroy<int>().connect<&listener::decr<int>>(listener);
 
-    auto e0 = registry.create();
-    auto e1 = registry.create();
-
-    registry.emplace<empty_type>(e0);
-    registry.emplace<empty_type>(e1);
+    registry.create(std::begin(entities), std::end(entities));
+    registry.insert<empty_type>(std::begin(entities), std::end(entities));
 
     ASSERT_EQ(listener.counter, 2);
-    ASSERT_EQ(listener.last, e1);
+    ASSERT_EQ(listener.last, entities[1u]);
 
-    registry.emplace<int>(e1);
-    registry.emplace<int>(e0);
+    registry.insert<int>(std::rbegin(entities), std::rend(entities));
 
     ASSERT_EQ(listener.counter, 4);
-    ASSERT_EQ(listener.last, e0);
+    ASSERT_EQ(listener.last, entities[0u]);
 
-    registry.erase<empty_type>(e0);
-    registry.erase<int>(e0);
+    registry.erase<empty_type, int>(entities[0u]);
 
     ASSERT_EQ(listener.counter, 2);
-    ASSERT_EQ(listener.last, e0);
+    ASSERT_EQ(listener.last, entities[0u]);
 
     registry.on_destroy<empty_type>().disconnect<&listener::decr<empty_type>>(listener);
     registry.on_destroy<int>().disconnect<&listener::decr<int>>(listener);
 
-    registry.erase<empty_type>(e1);
-    registry.erase<int>(e1);
+    registry.erase<empty_type, int>(entities[1u]);
 
     ASSERT_EQ(listener.counter, 2);
-    ASSERT_EQ(listener.last, e0);
+    ASSERT_EQ(listener.last, entities[0u]);
 
     registry.on_construct<empty_type>().disconnect<&listener::incr<empty_type>>(listener);
     registry.on_construct<int>().disconnect<&listener::incr<int>>(listener);
 
-    registry.emplace<empty_type>(e1);
-    registry.emplace<int>(e1);
+    registry.emplace<empty_type>(entities[1u]);
+    registry.emplace<int>(entities[1u]);
 
     ASSERT_EQ(listener.counter, 2);
-    ASSERT_EQ(listener.last, e0);
+    ASSERT_EQ(listener.last, entities[0u]);
 
     registry.on_construct<int>().connect<&listener::incr<int>>(listener);
     registry.on_destroy<int>().connect<&listener::decr<int>>(listener);
 
-    registry.emplace<int>(e0);
-    registry.erase<int>(e1);
+    registry.emplace<int>(entities[0u]);
+    registry.erase<int>(entities[1u]);
 
     ASSERT_EQ(listener.counter, 2);
-    ASSERT_EQ(listener.last, e1);
+    ASSERT_EQ(listener.last, entities[1u]);
 
     registry.on_construct<empty_type>().connect<&listener::incr<empty_type>>(listener);
     registry.on_destroy<empty_type>().connect<&listener::decr<empty_type>>(listener);
 
-    registry.erase<empty_type>(e1);
-    registry.emplace<empty_type>(e0);
+    registry.erase<empty_type>(entities[1u]);
+    registry.emplace<empty_type>(entities[0u]);
 
     ASSERT_EQ(listener.counter, 2);
-    ASSERT_EQ(listener.last, e0);
+    ASSERT_EQ(listener.last, entities[0u]);
 
-    registry.clear<empty_type>();
-    registry.clear<int>();
+    registry.clear<empty_type, int>();
 
     ASSERT_EQ(listener.counter, 0);
-    ASSERT_EQ(listener.last, e0);
+    ASSERT_EQ(listener.last, entities[0u]);
 
-    registry.emplace<empty_type>(e0);
-    registry.emplace<empty_type>(e1);
-    registry.emplace<int>(e0);
-    registry.emplace<int>(e1);
-
-    registry.destroy(e1);
+    registry.insert<empty_type>(std::begin(entities), std::end(entities));
+    registry.insert<int>(std::begin(entities), std::end(entities));
+    registry.destroy(entities[1u]);
 
     ASSERT_EQ(listener.counter, 2);
-    ASSERT_EQ(listener.last, e1);
+    ASSERT_EQ(listener.last, entities[1u]);
 
-    registry.erase<int>(e0);
-    registry.erase<empty_type>(e0);
-    registry.emplace_or_replace<int>(e0);
-    registry.emplace_or_replace<empty_type>(e0);
+    registry.erase<int, empty_type>(entities[0u]);
+    registry.emplace_or_replace<int>(entities[0u]);
+    registry.emplace_or_replace<empty_type>(entities[0u]);
 
     ASSERT_EQ(listener.counter, 2);
-    ASSERT_EQ(listener.last, e0);
+    ASSERT_EQ(listener.last, entities[0u]);
 
     registry.on_destroy<empty_type>().disconnect<&listener::decr<empty_type>>(listener);
     registry.on_destroy<int>().disconnect<&listener::decr<int>>(listener);
 
-    registry.emplace_or_replace<empty_type>(e0);
-    registry.emplace_or_replace<int>(e0);
+    registry.emplace_or_replace<empty_type>(entities[0u]);
+    registry.emplace_or_replace<int>(entities[0u]);
 
     ASSERT_EQ(listener.counter, 2);
-    ASSERT_EQ(listener.last, e0);
+    ASSERT_EQ(listener.last, entities[0u]);
 
     registry.on_update<empty_type>().connect<&listener::incr<empty_type>>(listener);
     registry.on_update<int>().connect<&listener::incr<int>>(listener);
 
-    registry.emplace_or_replace<empty_type>(e0);
-    registry.emplace_or_replace<int>(e0);
+    registry.emplace_or_replace<empty_type>(entities[0u]);
+    registry.emplace_or_replace<int>(entities[0u]);
 
     ASSERT_EQ(listener.counter, 4);
-    ASSERT_EQ(listener.last, e0);
+    ASSERT_EQ(listener.last, entities[0u]);
 
-    registry.replace<empty_type>(e0);
-    registry.replace<int>(e0);
+    registry.replace<empty_type>(entities[0u]);
+    registry.replace<int>(entities[0u]);
 
     ASSERT_EQ(listener.counter, 6);
-    ASSERT_EQ(listener.last, e0);
+    ASSERT_EQ(listener.last, entities[0u]);
 }
 
 TEST(Registry, Insert) {
     entt::registry registry;
+    entt::entity entities[3u];
 
-    const auto e0 = registry.create();
-    const auto e1 = registry.create();
-    const auto e2 = registry.create();
+    registry.create(std::begin(entities), std::end(entities));
 
-    registry.emplace<int>(e0);
-    registry.emplace<char>(e0);
-    registry.emplace<double>(e0);
+    registry.emplace<int>(entities[0u]);
+    registry.emplace<char>(entities[0u]);
+    registry.emplace<double>(entities[0u]);
 
-    registry.emplace<int>(e1);
-    registry.emplace<char>(e1);
+    registry.emplace<int>(entities[1u]);
+    registry.emplace<char>(entities[1u]);
 
-    registry.emplace<int>(e2);
+    registry.emplace<int>(entities[2u]);
 
-    ASSERT_FALSE(registry.all_of<float>(e0));
-    ASSERT_FALSE(registry.all_of<float>(e1));
-    ASSERT_FALSE(registry.all_of<float>(e2));
+    ASSERT_FALSE(registry.all_of<float>(entities[0u]));
+    ASSERT_FALSE(registry.all_of<float>(entities[1u]));
+    ASSERT_FALSE(registry.all_of<float>(entities[2u]));
 
     const auto icview = registry.view<int, char>();
     registry.insert(icview.begin(), icview.end(), 3.f);
 
-    ASSERT_EQ(registry.get<float>(e0), 3.f);
-    ASSERT_EQ(registry.get<float>(e1), 3.f);
-    ASSERT_FALSE(registry.all_of<float>(e2));
+    ASSERT_EQ(registry.get<float>(entities[0u]), 3.f);
+    ASSERT_EQ(registry.get<float>(entities[1u]), 3.f);
+    ASSERT_FALSE(registry.all_of<float>(entities[2u]));
 
     registry.clear<float>();
     float value[3]{0.f, 1.f, 2.f};
@@ -1391,40 +1394,39 @@ TEST(Registry, Insert) {
     const auto iview = registry.view<int>();
     registry.insert<float>(iview.data(), iview.data() + iview.size(), value);
 
-    ASSERT_EQ(registry.get<float>(e0), 0.f);
-    ASSERT_EQ(registry.get<float>(e1), 1.f);
-    ASSERT_EQ(registry.get<float>(e2), 2.f);
+    ASSERT_EQ(registry.get<float>(entities[0u]), 0.f);
+    ASSERT_EQ(registry.get<float>(entities[1u]), 1.f);
+    ASSERT_EQ(registry.get<float>(entities[2u]), 2.f);
 }
 
 TEST(Registry, Erase) {
     entt::registry registry;
     const auto iview = registry.view<int>();
     const auto icview = registry.view<int, char>();
+    entt::entity entities[3u];
 
-    const auto e0 = registry.create();
-    const auto e1 = registry.create();
-    const auto e2 = registry.create();
+    registry.create(std::begin(entities), std::end(entities));
 
-    registry.emplace<int>(e0);
-    registry.emplace<char>(e0);
-    registry.emplace<double>(e0);
+    registry.emplace<int>(entities[0u]);
+    registry.emplace<char>(entities[0u]);
+    registry.emplace<double>(entities[0u]);
 
-    registry.emplace<int>(e1);
-    registry.emplace<char>(e1);
+    registry.emplace<int>(entities[1u]);
+    registry.emplace<char>(entities[1u]);
 
-    registry.emplace<int>(e2);
+    registry.emplace<int>(entities[2u]);
 
-    ASSERT_TRUE(registry.any_of<int>(e0));
-    ASSERT_TRUE(registry.all_of<int>(e1));
-    ASSERT_TRUE(registry.any_of<int>(e2));
+    ASSERT_TRUE(registry.any_of<int>(entities[0u]));
+    ASSERT_TRUE(registry.all_of<int>(entities[1u]));
+    ASSERT_TRUE(registry.any_of<int>(entities[2u]));
 
-    registry.erase<int, char>(e0);
-    registry.erase<int, char>(icview.begin(), icview.end());
+    registry.erase<int, char>(entities[0u]);
     registry.erase<int, char>(icview.begin(), icview.end());
+    registry.erase<int, char>(icview.rbegin(), icview.rend());
 
-    ASSERT_FALSE(registry.any_of<int>(e0));
-    ASSERT_FALSE(registry.all_of<int>(e1));
-    ASSERT_TRUE(registry.any_of<int>(e2));
+    ASSERT_FALSE(registry.any_of<int>(entities[0u]));
+    ASSERT_FALSE(registry.all_of<int>(entities[1u]));
+    ASSERT_TRUE(registry.any_of<int>(entities[2u]));
 
     ASSERT_EQ(registry.size<int>(), 1u);
     ASSERT_EQ(registry.size<char>(), 0u);
@@ -1432,46 +1434,61 @@ TEST(Registry, Erase) {
 
     registry.erase<int>(iview.begin(), iview.end());
 
-    ASSERT_DEATH(registry.erase<int>(e0), "");
-    ASSERT_DEATH(registry.erase<int>(e1), "");
+    ASSERT_DEATH(registry.erase<int>(entities[0u]), "");
+    ASSERT_DEATH(registry.erase<int>(entities[1u]), "");
 
-    ASSERT_FALSE(registry.any_of<int>(e2));
-    ASSERT_NO_FATAL_FAILURE(registry.erase<int>(iview.begin(), iview.end()));
+    ASSERT_FALSE(registry.any_of<int>(entities[2u]));
+    ASSERT_NO_FATAL_FAILURE(registry.erase<int>(iview.rbegin(), iview.rend()));
 
     ASSERT_EQ(registry.size<int>(), 0u);
     ASSERT_EQ(registry.size<char>(), 0u);
     ASSERT_EQ(registry.size<double>(), 1u);
+
+    registry.insert<int>(std::begin(entities), std::end(entities));
+    registry.insert<char>(std::begin(entities), std::end(entities));
+
+    ASSERT_EQ(registry.size<int>(), 3u);
+    ASSERT_EQ(registry.size<char>(), 3u);
+
+    registry.erase<int, char>(std::begin(entities), std::end(entities));
+
+    ASSERT_DEATH((registry.erase<int, char>(std::begin(entities), std::end(entities))), "");
+    ASSERT_EQ(registry.size<int>(), 0u);
+    ASSERT_EQ(registry.size<char>(), 0u);
+
+    ASSERT_FALSE(registry.orphan(entities[0u]));
+    ASSERT_TRUE(registry.orphan(entities[1u]));
+    ASSERT_TRUE(registry.orphan(entities[2u]));
 }
 
 TEST(Registry, StableErase) {
     entt::registry registry;
     const auto iview = registry.view<int>();
     const auto icview = registry.view<int, stable_type>();
+    entt::entity entities[3u];
 
-    const auto e0 = registry.create();
-    const auto e1 = registry.create();
-    const auto e2 = registry.create();
+    registry.create(std::begin(entities), std::end(entities));
 
-    registry.emplace<int>(e0);
-    registry.emplace<stable_type>(e0);
-    registry.emplace<double>(e0);
+    registry.emplace<int>(entities[0u]);
+    registry.emplace<stable_type>(entities[0u]);
+    registry.emplace<double>(entities[0u]);
 
-    registry.emplace<int>(e1);
-    registry.emplace<stable_type>(e1);
+    registry.emplace<int>(entities[1u]);
+    registry.emplace<stable_type>(entities[1u]);
 
-    registry.emplace<int>(e2);
+    registry.emplace<int>(entities[2u]);
 
-    ASSERT_TRUE(registry.any_of<int>(e0));
-    ASSERT_TRUE(registry.all_of<int>(e1));
-    ASSERT_TRUE(registry.any_of<int>(e2));
+    ASSERT_TRUE(registry.any_of<int>(entities[0u]));
+    ASSERT_TRUE(registry.all_of<int>(entities[1u]));
+    ASSERT_TRUE(registry.any_of<int>(entities[2u]));
 
-    registry.erase<int, stable_type>(e0);
+    registry.erase<int, stable_type>(entities[0u]);
     registry.erase<int, stable_type>(icview.begin(), icview.end());
     registry.erase<int, stable_type>(icview.begin(), icview.end());
 
-    ASSERT_FALSE(registry.any_of<int>(e0));
-    ASSERT_FALSE(registry.all_of<int>(e1));
-    ASSERT_TRUE(registry.any_of<int>(e2));
+    ASSERT_FALSE(registry.any_of<int>(entities[0u]));
+    ASSERT_FALSE(registry.all_of<int>(entities[1u]));
+    ASSERT_TRUE(registry.any_of<int>(entities[2u]));
 
     ASSERT_EQ(registry.size<int>(), 1u);
     ASSERT_EQ(registry.size<stable_type>(), 2u);
@@ -1479,10 +1496,10 @@ TEST(Registry, StableErase) {
 
     registry.erase<int>(iview.begin(), iview.end());
 
-    ASSERT_DEATH(registry.erase<int>(e0), "");
-    ASSERT_DEATH(registry.erase<int>(e1), "");
+    ASSERT_DEATH(registry.erase<int>(entities[0u]), "");
+    ASSERT_DEATH(registry.erase<int>(entities[1u]), "");
 
-    ASSERT_FALSE(registry.any_of<int>(e2));
+    ASSERT_FALSE(registry.any_of<int>(entities[2u]));
 
     ASSERT_EQ(registry.size<int>(), 0u);
     ASSERT_EQ(registry.size<stable_type>(), 2u);
@@ -1493,32 +1510,31 @@ TEST(Registry, Remove) {
     entt::registry registry;
     const auto iview = registry.view<int>();
     const auto icview = registry.view<int, char>();
+    entt::entity entities[3u];
 
-    const auto e0 = registry.create();
-    const auto e1 = registry.create();
-    const auto e2 = registry.create();
+    registry.create(std::begin(entities), std::end(entities));
 
-    registry.emplace<int>(e0);
-    registry.emplace<char>(e0);
-    registry.emplace<double>(e0);
+    registry.emplace<int>(entities[0u]);
+    registry.emplace<char>(entities[0u]);
+    registry.emplace<double>(entities[0u]);
 
-    registry.emplace<int>(e1);
-    registry.emplace<char>(e1);
+    registry.emplace<int>(entities[1u]);
+    registry.emplace<char>(entities[1u]);
 
-    registry.emplace<int>(e2);
+    registry.emplace<int>(entities[2u]);
 
-    ASSERT_TRUE(registry.any_of<int>(e0));
-    ASSERT_TRUE(registry.all_of<int>(e1));
-    ASSERT_TRUE(registry.any_of<int>(e2));
+    ASSERT_TRUE(registry.any_of<int>(entities[0u]));
+    ASSERT_TRUE(registry.all_of<int>(entities[1u]));
+    ASSERT_TRUE(registry.any_of<int>(entities[2u]));
 
-    registry.remove<int, char>(e0);
+    registry.remove<int, char>(entities[0u]);
 
     ASSERT_EQ((registry.remove<int, char>(icview.begin(), icview.end())), 2u);
-    ASSERT_EQ((registry.remove<int, char>(icview.begin(), icview.end())), 0u);
+    ASSERT_EQ((registry.remove<int, char>(icview.rbegin(), icview.rend())), 0u);
 
-    ASSERT_FALSE(registry.any_of<int>(e0));
-    ASSERT_FALSE(registry.all_of<int>(e1));
-    ASSERT_TRUE(registry.any_of<int>(e2));
+    ASSERT_FALSE(registry.any_of<int>(entities[0u]));
+    ASSERT_FALSE(registry.all_of<int>(entities[1u]));
+    ASSERT_TRUE(registry.any_of<int>(entities[2u]));
 
     ASSERT_EQ(registry.size<int>(), 1u);
     ASSERT_EQ(registry.size<char>(), 0u);
@@ -1526,47 +1542,62 @@ TEST(Registry, Remove) {
 
     ASSERT_EQ((registry.remove<int>(iview.begin(), iview.end())), 1u);
 
-    ASSERT_EQ(registry.remove<int>(e0), 0u);
-    ASSERT_EQ(registry.remove<int>(e1), 0u);
+    ASSERT_EQ(registry.remove<int>(entities[0u]), 0u);
+    ASSERT_EQ(registry.remove<int>(entities[1u]), 0u);
 
-    ASSERT_FALSE(registry.any_of<int>(e2));
+    ASSERT_FALSE(registry.any_of<int>(entities[2u]));
     ASSERT_EQ(registry.remove<int>(iview.begin(), iview.end()), 0u);
 
     ASSERT_EQ(registry.size<int>(), 0u);
     ASSERT_EQ(registry.size<char>(), 0u);
     ASSERT_EQ(registry.size<double>(), 1u);
+
+    registry.insert<int>(std::begin(entities), std::end(entities));
+    registry.insert<char>(std::begin(entities), std::end(entities));
+
+    ASSERT_EQ(registry.size<int>(), 3u);
+    ASSERT_EQ(registry.size<char>(), 3u);
+
+    registry.remove<int, char>(std::begin(entities), std::end(entities));
+    registry.remove<int, char>(std::begin(entities), std::end(entities));
+
+    ASSERT_EQ(registry.size<int>(), 0u);
+    ASSERT_EQ(registry.size<char>(), 0u);
+
+    ASSERT_FALSE(registry.orphan(entities[0u]));
+    ASSERT_TRUE(registry.orphan(entities[1u]));
+    ASSERT_TRUE(registry.orphan(entities[2u]));
 }
 
 TEST(Registry, StableRemove) {
     entt::registry registry;
     const auto iview = registry.view<int>();
     const auto icview = registry.view<int, stable_type>();
+    entt::entity entities[3u];
 
-    const auto e0 = registry.create();
-    const auto e1 = registry.create();
-    const auto e2 = registry.create();
+    registry.create(std::begin(entities), std::end(entities));
 
-    registry.emplace<int>(e0);
-    registry.emplace<stable_type>(e0);
-    registry.emplace<double>(e0);
+    registry.emplace<int>(entities[0u]);
+    registry.emplace<stable_type>(entities[0u]);
+    registry.emplace<double>(entities[0u]);
 
-    registry.emplace<int>(e1);
-    registry.emplace<stable_type>(e1);
+    registry.emplace<int>(entities[1u]);
+    registry.emplace<stable_type>(entities[1u]);
 
-    registry.emplace<int>(e2);
+    registry.emplace<int>(entities[2u]);
 
-    ASSERT_TRUE(registry.any_of<int>(e0));
-    ASSERT_TRUE(registry.all_of<int>(e1));
-    ASSERT_TRUE(registry.any_of<int>(e2));
+    ASSERT_TRUE(registry.any_of<int>(entities[0u]));
+    ASSERT_TRUE(registry.all_of<int>(entities[1u]));
+    ASSERT_TRUE(registry.any_of<int>(entities[2u]));
 
-    registry.remove<int, stable_type>(e0);
+    registry.remove<int, stable_type>(entities[0u]);
 
     ASSERT_EQ((registry.remove<int, stable_type>(icview.begin(), icview.end())), 2u);
-    ASSERT_EQ((registry.remove<int, stable_type>(icview.begin(), icview.end())), 0u);
+    ASSERT_EQ((registry.remove<int, stable_type>(icview.rbegin(), icview.rend())), 0u);
 
-    ASSERT_FALSE(registry.any_of<int>(e0));
-    ASSERT_FALSE(registry.all_of<int>(e1));
-    ASSERT_TRUE(registry.any_of<int>(e2));
+    ASSERT_FALSE(registry.any_of<int>(entities[0u]));
+    ASSERT_FALSE(registry.all_of<int>(entities[1u]));
+    ASSERT_TRUE(registry.any_of<int>(entities[2u]));
 
     ASSERT_EQ(registry.size<int>(), 1u);
     ASSERT_EQ(registry.size<stable_type>(), 2u);
@@ -1574,10 +1605,10 @@ TEST(Registry, StableRemove) {
 
     ASSERT_EQ((registry.remove<int>(iview.begin(), iview.end())), 1u);
 
-    ASSERT_EQ(registry.remove<int>(e0), 0u);
-    ASSERT_EQ(registry.remove<int>(e1), 0u);
+    ASSERT_EQ(registry.remove<int>(entities[0u]), 0u);
+    ASSERT_EQ(registry.remove<int>(entities[1u]), 0u);
 
-    ASSERT_FALSE(registry.any_of<int>(e2));
+    ASSERT_FALSE(registry.any_of<int>(entities[2u]));
 
     ASSERT_EQ(registry.size<int>(), 0u);
     ASSERT_EQ(registry.size<stable_type>(), 2u);
@@ -1586,21 +1617,20 @@ TEST(Registry, StableRemove) {
 
 TEST(Registry, Compact) {
     entt::registry registry;
+    entt::entity entities[2u];
 
-    const auto e0 = registry.create();
-    const auto e1 = registry.create();
+    registry.create(std::begin(entities), std::end(entities));
 
-    registry.emplace<int>(e0);
-    registry.emplace<stable_type>(e0);
+    registry.emplace<int>(entities[0u]);
+    registry.emplace<stable_type>(entities[0u]);
 
-    registry.emplace<int>(e1);
-    registry.emplace<stable_type>(e1);
+    registry.emplace<int>(entities[1u]);
+    registry.emplace<stable_type>(entities[1u]);
 
     ASSERT_EQ(registry.size<int>(), 2u);
     ASSERT_EQ(registry.size<stable_type>(), 2u);
 
-    registry.destroy(e0);
-    registry.destroy(e1);
+    registry.destroy(std::begin(entities), std::end(entities));
 
     ASSERT_EQ(registry.size<int>(), 0u);
     ASSERT_EQ(registry.size<stable_type>(), 2u);