meta: reduce cost of meta base

src/entt/meta/factory.hpp

@@ -62,15 +62,16 @@ protected:
     void insert_or_assign(Type node) {
         reset_bucket(parent);
 
+        std::size_t pos{};
+
         if constexpr(std::is_same_v<Type, meta_base_node>) {
-            details->base.insert_or_assign(node.id, node);
+            for(const std::size_t last = details->base.size(); (pos != last) && (details->base[pos].id != node.id); ++pos) {}
+            (pos == details->base.size()) ? details->base.emplace_back(node) : (details->base[pos] = node);
         } else if constexpr(std::is_same_v<Type, meta_conv_node>) {
-            std::size_t pos{};
             for(const std::size_t last = details->conv.size(); (pos != last) && (details->conv[pos].type != node.type); ++pos) {}
             (pos == details->conv.size()) ? details->conv.emplace_back(node) : (details->conv[pos] = node);
         } else {
             static_assert(std::is_same_v<Type, meta_ctor_node>, "Unexpected type");
-            std::size_t pos{};
             for(const std::size_t last = details->ctor.size(); (pos != last) && (details->ctor[pos].id != node.id); ++pos) {}
             (pos == details->ctor.size()) ? details->ctor.emplace_back(node) : (details->ctor[pos] = node);
         }

src/entt/meta/meta.hpp

@@ -1179,7 +1179,9 @@ class meta_type {
                         bool can_continue = type.node.conversion_helper && other.node.conversion_helper;
 
                         if(!can_continue && type.node.details) {
-                            can_continue = type.node.details->base.contains(info.hash());
+                            for(std::size_t idx{}, last = type.node.details->base.size(); !can_continue && idx != last; ++idx) {
+                                can_continue = (type.node.details->base[idx].id == info.hash());
+                            }
 
                             for(std::size_t idx{}, last = type.node.details->conv.size(); !can_continue && idx != last; ++idx) {
                                 can_continue = (type.node.details->conv[idx].type == info.hash());

src/entt/meta/node.hpp

@@ -7,7 +7,6 @@
 #include <utility>
 #include <vector>
 #include "../config/config.h"
-#include "../container/dense_map.hpp"
 #include "../core/attribute.h"
 #include "../core/bit.hpp"
 #include "../core/enum.hpp"
@@ -136,7 +135,7 @@ struct meta_template_node {
 
 struct meta_type_descriptor {
     std::vector<meta_ctor_node> ctor{};
-    dense_map<id_type, meta_base_node, identity> base{};
+    std::vector<meta_base_node> base{};
     std::vector<meta_conv_node> conv{};
     std::vector<meta_data_node> data{};
     std::vector<meta_func_node> func{};
@@ -171,7 +170,7 @@ auto *look_for(const meta_context &context, const meta_type_node &node, const id
         }
 
         for(auto &&curr: node.details->base) {
-            if(auto *elem = look_for<Member>(context, curr.second.type(context), id); elem) {
+            if(auto *elem = look_for<Member>(context, curr.type(context), id); elem) {
                 return elem;
             }
         }
@@ -199,7 +198,7 @@ template<typename... Args>
 
     if(from.details) {
         for(auto &&curr: from.details->base) {
-            if(const void *elem = try_cast(context, curr.second.type(context), to, curr.second.cast(instance)); elem) {
+            if(const void *elem = try_cast(context, curr.type(context), to, curr.cast(instance)); elem) {
                 return elem;
             }
         }
@@ -222,7 +221,7 @@ template<typename Func>
         }
 
         for(auto &&curr: from.details->base) {
-            if(auto other = try_convert(context, curr.second.type(context), to, arithmetic_or_enum, curr.second.cast(instance), func); other) {
+            if(auto other = try_convert(context, curr.type(context), to, arithmetic_or_enum, curr.cast(instance), func); other) {
                 return other;
             }
         }