registry: better, faster range-remove + refine range-erase

Author: skypjack

src/entt/entity/registry.hpp

@@ -956,17 +956,28 @@ class basic_registry {
      */
     template<typename Type, typename... Other, typename It>
     size_type remove(It first, It last) {
+        size_type count{};
+
         if constexpr(sizeof...(Other) == 0u) {
-            return assure<Type>().remove(std::move(first), std::move(last));
-        } else {
-            size_type count{};
+            count += assure<Type>().remove(std::move(first), std::move(last));
+        } else if constexpr(std::is_same_v<It, typename basic_common_type::iterator>) {
+            constexpr size_type len = sizeof...(Other) + 1u;
+            basic_common_type *cpools[len]{&assure<Type>(), &assure<Other>()...};
+
+            for(size_type pos{}; pos < len; ++pos) {
+                if(cpools[pos]->data() == first.data()) {
+                    std::swap(cpools[pos], cpools[len - 1u]);
+                }
 
+                count += cpools[pos]->remove(first, last);
+            }
+        } else {
             for(auto cpools = std::forward_as_tuple(assure<Type>(), assure<Other>()...); first != last; ++first) {
                 count += std::apply([entt = *first](auto &...curr) { return (curr.remove(entt) + ... + 0u); }, cpools);
             }
-
-            return count;
         }
+
+        return count;
     }
 
     /**
@@ -998,10 +1009,12 @@ class basic_registry {
      */
     template<typename Type, typename... Other, typename It>
     void erase(It first, It last) {
-        constexpr size_type len = sizeof...(Other) + 1u;
-        basic_common_type *cpools[len]{&assure<Type>(), &assure<Other>()...};
+        if constexpr(sizeof...(Other) == 0u) {
+            assure<Type>().erase(std::move(first), std::move(last));
+        } else if constexpr(std::is_same_v<It, typename basic_common_type::iterator>) {
+            constexpr size_type len = sizeof...(Other) + 1u;
+            basic_common_type *cpools[len]{&assure<Type>(), &assure<Other>()...};
 
-        if constexpr(std::is_same_v<It, typename basic_common_type::iterator>) {
             for(size_type pos{}; pos < len; ++pos) {
                 if(cpools[pos]->data() == first.data()) {
                     std::swap(cpools[pos], cpools[len - 1u]);
@@ -1010,12 +1023,8 @@ class basic_registry {
                 cpools[pos]->erase(first, last);
             }
         } else {
-            for(; first != last; ++first) {
-                const auto entt = *first;
-
-                for(size_type pos{}; pos < len; ++pos) {
-                    cpools[pos]->erase(entt);
-                }
+            for(auto cpools = std::forward_as_tuple(assure<Type>(), assure<Other>()...); first != last; ++first) {
+                std::apply([entt = *first](auto &...curr) { (curr.erase(entt), ...); }, cpools);
             }
         }
     }