Changed facts in DinkyECS to be a shared_ptr so that it is a singular data store instead of copied around. Closes #85.

dinkyecs.hpp

@@ -9,6 +9,7 @@
 #include <typeinfo>
 #include <unordered_map>
 #include <optional>
+#include <memory>
 
 namespace DinkyECS
 {
@@ -16,8 +17,6 @@ namespace DinkyECS
 
   const Entity NONE = 0;
 
-  using EntityMap = std::unordered_map<Entity, size_t>;
-
   template <typename T>
     struct ComponentStorage {
       std::vector<T> data;
@@ -29,17 +28,22 @@ namespace DinkyECS
     std::any data;
   };
 
-  typedef std::queue<Event> EventQueue;
+  using EntityMap = std::unordered_map<Entity, size_t>;
+  using EventQueue = std::queue<Event>;
+  using TypeMap = std::unordered_map<std::type_index, std::any>;
 
   struct World {
     unsigned long entity_count = NONE+1;
     std::unordered_map<std::type_index, EntityMap> $components;
-    std::unordered_map<std::type_index, std::any> $facts;
+    std::shared_ptr<TypeMap> $facts = nullptr;
     std::unordered_map<std::type_index, EventQueue> $events;
     std::unordered_map<std::type_index, std::any> $component_storages;
     std::unordered_map<std::type_index, std::queue<size_t>> $free_indices;
     std::unordered_map<Entity, bool> $constants;
 
+    World() : $facts(std::make_shared<TypeMap>())
+    {}
+
     Entity entity() { return ++entity_count; }
 
     void destroy(DinkyECS::Entity entity) {
@@ -135,26 +139,26 @@ namespace DinkyECS
 
     template <typename Comp>
       void set_the(Comp val) {
-        $facts.insert_or_assign(std::type_index(typeid(Comp)), val);
+        $facts->insert_or_assign(std::type_index(typeid(Comp)), val);
       }
 
     template <typename Comp>
       Comp &get_the() {
         auto comp_id = std::type_index(typeid(Comp));
-        dbc::check($facts.contains(comp_id),
+        dbc::check($facts->contains(comp_id),
             fmt::format("!!!! ATTEMPT to access world fact that hasn't "
               "been set yet: {}",
               typeid(Comp).name()));
 
         // use .at to get std::out_of_range if fact not set
-        std::any &res = $facts.at(comp_id);
+        std::any &res = $facts->at(comp_id);
         return std::any_cast<Comp &>(res);
       }
 
     template <typename Comp>
       bool has_the() {
         auto comp_id = std::type_index(typeid(Comp));
-        return $facts.contains(comp_id);
+        return $facts->contains(comp_id);
       }
 
     template <typename Comp>