minor changes

README.md

@@ -620,7 +620,7 @@ Because of how the registry works internally, it stores a couple of signal
 handlers for each pool in order to notify some of its data structures on the
 construction and destruction of components.<br/>
 These signal handlers are also exposed and made available to users. This is the
-basic brick to build fancy things like blueprints and reactive systems.
+basic brick to build fancy things like dependencies and reactive systems.
 
 To get a sink to be used to connect and disconnect listeners so as to be
 notified on the creation of a component, use the `construction` member function:

TODO

@@ -8,8 +8,8 @@
 * create dedicated flat map based on types implementation (sort of "type map") for types to use within the registry and so on...
 * does it worth it to add an optional functor to the member functions of snapshot so as to filter out instances and entities?
 * ease the assignment of tags as string (use a template class with a non-type template parameter behind the scene)
-* is it possible to reduce the storage used to manage empty components?
-* reintroduce meaningful copy/clone functionalities into the registry
+* reintroduce meaningful clone functionalities into the registry
+* improve CMake interface, see mail from Malte
 * is registry/utility.hpp really required?
 * "singleton mode" for tags (see #66)
 * AOB

src/entt/entity/helper.hpp

@@ -25,7 +25,7 @@ namespace entt {
  * @param entity A valid entity identifier.
  */
 template<typename Entity, typename... Component>
-void dependency(Registry<Entity> &registry, Entity entity) {
+void dependency(Registry<Entity> &registry, const Entity entity) {
     using accumulator_type = int[];
     accumulator_type accumulator = { ((registry.template has<Component>(entity) ? void() : (registry.template assign<Component>(entity), void())), 0)... };
     (void)accumulator;
@@ -50,7 +50,7 @@ void dependency(Registry<Entity> &registry, Entity entity) {
  * @param sink A sink object properly initialized.
  */
 template<typename... Dependency, typename Entity>
-void dependency(Sink<void(Registry<Entity> &, Entity)> sink) {
+void dependency(Sink<void(Registry<Entity> &, const Entity)> sink) {
     sink.template connect<dependency<Entity, Dependency...>>();
 }
 
@@ -73,7 +73,7 @@ void dependency(Sink<void(Registry<Entity> &, Entity)> sink) {
  * @param sink A sink object properly initialized.
  */
 template<typename... Dependency, typename Entity>
-void dependency(break_t, Sink<void(Registry<Entity> &, Entity)> sink) {
+void dependency(break_t, Sink<void(Registry<Entity> &, const Entity)> sink) {
     sink.template disconnect<dependency<Entity, Dependency...>>();
 }
 

src/entt/entity/prototype.hpp

@@ -31,18 +31,18 @@ namespace entt {
 template<typename Entity>
 class Prototype {
     using component_type = typename Registry<Entity>::component_type;
-    using fn_type = void(*)(const void *, Registry<Entity> &, Entity);
+    using fn_type = void(*)(Registry<Entity> &, const Entity, const void *);
     using deleter_type = void(*)(void *);
     using ptr_type = std::unique_ptr<void, deleter_type>;
 
     template<typename Component>
-    static void accommodate(const void *component, Registry<Entity> &registry, Entity entity) {
+    static void accommodate(Registry<Entity> &registry, const Entity entity, const void *component) {
         const auto &ref = *static_cast<const Component *>(component);
         registry.template accommodate<Component>(entity, ref);
     }
 
     template<typename Component>
-    static void assign(const void *component, Registry<Entity> &registry, Entity entity) {
+    static void assign(Registry<Entity> &registry, const Entity entity, const void *component) {
         if(!registry.template has<Component>(entity)) {
             const auto &ref = *static_cast<const Component *>(component);
             registry.template assign<Component>(entity, ref);
@@ -50,7 +50,7 @@ class Prototype {
     }
 
     struct Handler final {
-        Handler(ptr_type component, fn_type accommodate, fn_type assign, component_type type)
+        Handler(ptr_type component, const fn_type accommodate, const fn_type assign, const component_type type)
             : component{std::move(component)},
               accommodate{accommodate},
               assign{assign},
@@ -245,9 +245,9 @@ public:
      * @param registry A valid reference to a registry.
      * @param entity A valid entity identifier.
      */
-    void assign(registry_type &registry, entity_type entity) {
+    void assign(registry_type &registry, const entity_type entity) {
         std::for_each(handlers.begin(), handlers.end(), [&registry, entity](auto &&handler) {
-            handler.assign(handler.component.get(), registry, entity);
+            handler.assign(registry, entity, handler.component.get());
         });
     }
 
@@ -265,9 +265,9 @@ public:
      * @param registry A valid reference to a registry.
      * @param entity A valid entity identifier.
      */
-    void accommodate(registry_type &registry, entity_type entity) {
+    void accommodate(registry_type &registry, const entity_type entity) {
         std::for_each(handlers.begin(), handlers.end(), [&registry, entity](auto &&handler) {
-            handler.accommodate(handler.component.get(), registry, entity);
+            handler.accommodate(registry, entity, handler.component.get());
         });
     }
 
@@ -287,7 +287,7 @@ public:
      * @param registry A valid reference to a registry.
      * @param entity A valid entity identifier.
      */
-    inline void operator()(registry_type &registry, entity_type entity) ENTT_NOEXCEPT {
+    inline void operator()(registry_type &registry, const entity_type entity) ENTT_NOEXCEPT {
         assign(registry, entity);
     }
 

src/entt/entity/registry.hpp

@@ -40,24 +40,24 @@ class Registry {
     using tag_family = Family<struct InternalRegistryTagFamily>;
     using component_family = Family<struct InternalRegistryComponentFamily>;
     using handler_family = Family<struct InternalRegistryHandlerFamily>;
-    using signal_type = SigH<void(Registry &, Entity)>;
+    using signal_type = SigH<void(Registry &, const Entity)>;
     using traits_type = entt_traits<Entity>;
 
     template<typename... Component>
-    static void creating(Registry &registry, Entity entity) {
+    static void creating(Registry &registry, const Entity entity) {
         if(registry.has<Component...>(entity)) {
             registry.handlers[handler_family::type<Component...>()]->construct(entity);
         }
     }
 
     template<typename... Component>
-    static void destroying(Registry &registry, Entity entity) {
+    static void destroying(Registry &registry, const Entity entity) {
         auto &handler = *registry.handlers[handler_family::type<Component...>()];
         return handler.has(entity) ? handler.destroy(entity) : void();
     }
 
     struct Attachee {
-        Attachee(Entity entity): entity{entity} {}
+        Attachee(const Entity entity): entity{entity} {}
         virtual ~Attachee() = default;
         Entity entity;
     };
@@ -66,8 +66,8 @@ class Registry {
     struct Attaching: Attachee {
         // requirements for aggregates are relaxed only since C++17
         template<typename... Args>
-        Attaching(Entity entity, Tag tag)
-            : Attachee{entity}, tag{std::move(tag)}
+        Attaching(const Entity entity, Args &&... args)
+            : Attachee{entity}, tag{std::forward<Args>(args)...}
         {}
 
         Tag tag;
@@ -204,7 +204,7 @@ public:
      * @param cap Desired capacity.
      */
     template<typename Component>
-    void reserve(size_type cap) {
+    void reserve(const size_type cap) {
         assure<Component>();
         pool<Component>().reserve(cap);
     }
@@ -217,7 +217,7 @@ public:
      *
      * @param cap Desired capacity.
      */
-    void reserve(size_type cap) {
+    void reserve(const size_type cap) {
         entities.reserve(cap);
     }
 
@@ -310,7 +310,7 @@ public:
      * @param entity An entity identifier, either valid or not.
      * @return True if the identifier is valid, false otherwise.
      */
-    bool valid(entity_type entity) const ENTT_NOEXCEPT {
+    bool valid(const entity_type entity) const ENTT_NOEXCEPT {
         const auto pos = size_type(entity & traits_type::entity_mask);
         return (pos < entities.size() && entities[pos] == entity);
     }
@@ -332,7 +332,7 @@ public:
      * @param entity A valid entity identifier.
      * @return True if the identifier is valid, false otherwise.
      */
-    bool fast(entity_type entity) const ENTT_NOEXCEPT {
+    bool fast(const entity_type entity) const ENTT_NOEXCEPT {
         const auto pos = size_type(entity & traits_type::entity_mask);
         assert(pos < entities.size());
         return (entities[pos] == entity);
@@ -343,7 +343,7 @@ public:
      * @param entity An entity identifier, either valid or not.
      * @return Version stored along with the given entity identifier.
      */
-    version_type version(entity_type entity) const ENTT_NOEXCEPT {
+    version_type version(const entity_type entity) const ENTT_NOEXCEPT {
         return version_type((entity >> traits_type::entity_shift) & traits_type::version_mask);
     }
 
@@ -364,7 +364,7 @@ public:
      * @param entity A valid entity identifier.
      * @return Actual version for the given entity identifier.
      */
-    version_type current(entity_type entity) const ENTT_NOEXCEPT {
+    version_type current(const entity_type entity) const ENTT_NOEXCEPT {
         const auto pos = size_type(entity & traits_type::entity_mask);
         assert(pos < entities.size());
         return version_type((entities[pos] >> traits_type::entity_shift) & traits_type::version_mask);
@@ -422,7 +422,7 @@ public:
      *
      * @param entity A valid entity identifier
      */
-    void destroy(entity_type entity) {
+    void destroy(const entity_type entity) {
         assert(valid(entity));
 
         for(auto pos = pools.size(); pos; --pos) {
@@ -478,12 +478,12 @@ public:
      * @return A reference to the newly created tag.
      */
     template<typename Tag, typename... Args>
-    Tag & assign(tag_t, entity_type entity, Args &&... args) {
+    Tag & assign(tag_t, const entity_type entity, Args &&... args) {
         assert(valid(entity));
         assert(!has<Tag>());
         assure<Tag>(tag_t{});
         auto &tup = tags[tag_family::type<Tag>()];
-        std::get<0>(tup).reset(new Attaching<Tag>{entity, Tag{std::forward<Args>(args)...}});
+        std::get<0>(tup).reset(new Attaching<Tag>{entity, std::forward<Args>(args)...});
         std::get<1>(tup).publish(*this, entity);
         return get<Tag>();
     }
@@ -509,7 +509,7 @@ public:
      * @return A reference to the newly created component.
      */
     template<typename Component, typename... Args>
-    Component & assign(entity_type entity, Args &&... args) {
+    Component & assign(const entity_type entity, Args &&... args) {
         assert(valid(entity));
         assure<Component>();
         pool<Component>().construct(entity, std::forward<Args>(args)...);
@@ -545,7 +545,7 @@ public:
      * @param entity A valid entity identifier.
      */
     template<typename Component>
-    void remove(entity_type entity) {
+    void remove(const entity_type entity) {
         assert(valid(entity));
         assert(managed<Component>());
         const auto ctype = component_family::type<Component>();
@@ -586,7 +586,7 @@ public:
      * @return True if the entity owns the tag, false otherwise.
      */
     template<typename Tag>
-    bool has(tag_t, entity_type entity) const ENTT_NOEXCEPT {
+    bool has(tag_t, const entity_type entity) const ENTT_NOEXCEPT {
         return has<Tag>() && attachee<Tag>() == entity;
     }
 
@@ -603,7 +603,7 @@ public:
      * @return True if the entity has all the components, false otherwise.
      */
     template<typename... Component>
-    bool has(entity_type entity) const ENTT_NOEXCEPT {
+    bool has(const entity_type entity) const ENTT_NOEXCEPT {
         assert(valid(entity));
         bool all = true;
         using accumulator_type = bool[];
@@ -662,7 +662,7 @@ public:
      * @return A reference to the component owned by the entity.
      */
     template<typename Component>
-    const Component & get(entity_type entity) const ENTT_NOEXCEPT {
+    const Component & get(const entity_type entity) const ENTT_NOEXCEPT {
         assert(valid(entity));
         assert(managed<Component>());
         return pool<Component>().get(entity);
@@ -683,7 +683,7 @@ public:
      * @return A reference to the component owned by the entity.
      */
     template<typename Component>
-    inline Component & get(entity_type entity) ENTT_NOEXCEPT {
+    inline Component & get(const entity_type entity) ENTT_NOEXCEPT {
         return const_cast<Component &>(const_cast<const Registry *>(this)->get<Component>(entity));
     }
 
@@ -703,7 +703,7 @@ public:
      */
     template<typename... Component>
     std::enable_if_t<(sizeof...(Component) > 1), std::tuple<const Component &...>>
-    get(entity_type entity) const ENTT_NOEXCEPT {
+    get(const entity_type entity) const ENTT_NOEXCEPT {
         return std::tuple<const Component &...>{get<Component>(entity)...};
     }
 
@@ -723,7 +723,7 @@ public:
      */
     template<typename... Component>
     std::enable_if_t<(sizeof...(Component) > 1), std::tuple<Component &...>>
-    get(entity_type entity) ENTT_NOEXCEPT {
+    get(const entity_type entity) ENTT_NOEXCEPT {
         return std::tuple<Component &...>{get<Component>(entity)...};
     }
 
@@ -771,7 +771,7 @@ public:
      * @return A reference to the newly created component.
      */
     template<typename Component, typename... Args>
-    Component & replace(entity_type entity, Args &&... args) {
+    Component & replace(const entity_type entity, Args &&... args) {
         return (get<Component>(entity) = Component{std::forward<Args>(args)...});
     }
 
@@ -792,7 +792,7 @@ public:
      * @return A valid entity identifier.
      */
     template<typename Tag>
-    entity_type move(entity_type entity) {
+    entity_type move(const entity_type entity) {
         assert(valid(entity));
         assert(has<Tag>());
         auto &tag = std::get<0>(tags[tag_family::type<Tag>()]);
@@ -846,7 +846,7 @@ public:
      * @return A reference to the newly created component.
      */
     template<typename Component, typename... Args>
-    Component & accommodate(entity_type entity, Args &&... args) {
+    Component & accommodate(const entity_type entity, Args &&... args) {
         assure<Component>();
         auto &cpool = pool<Component>();
 
@@ -1068,7 +1068,7 @@ public:
      * @param entity A valid entity identifier.
      */
     template<typename Component>
-    void reset(entity_type entity) {
+    void reset(const entity_type entity) {
         assert(valid(entity));
         assure<Component>();
         const auto ctype = component_family::type<Component>();
@@ -1110,7 +1110,7 @@ public:
      * to know if they are still valid.
      */
     void reset() {
-        each([this](auto entity) {
+        each([this](const auto entity) {
             destroy(entity);
         });
     }
@@ -1122,7 +1122,7 @@ public:
      * The signature of the function should be equivalent to the following:
      *
      * @code{.cpp}
-     * void(entity_type);
+     * void(const entity_type);
      * @endcode
      *
      * This function is fairly slow and should not be used frequently.<br/>
@@ -1163,7 +1163,7 @@ public:
      * @param entity A valid entity identifier.
      * @return True if the entity is an orphan, false otherwise.
      */
-    bool orphan(entity_type entity) const {
+    bool orphan(const entity_type entity) const {
         assert(valid(entity));
         bool orphan = true;
 
@@ -1188,7 +1188,7 @@ public:
      * The signature of the function should be equivalent to the following:
      *
      * @code{.cpp}
-     * void(entity_type);
+     * void(const entity_type);
      * @endcode
      *
      * This function can be very slow and should not be used frequently.
@@ -1198,7 +1198,7 @@ public:
      */
     template<typename Func>
     void orphans(Func func) const {
-        each([func = std::move(func), this](auto entity) {
+        each([func = std::move(func), this](const auto entity) {
             if(orphan(entity)) {
                 func(entity);
             }
@@ -1276,7 +1276,7 @@ public:
                 handler->construct(entity);
             }
 
-            auto connect = [this](auto ctype) {
+            auto connect = [this](const auto ctype) {
                 auto &cpool = pools[ctype];
                 std::get<1>(cpool).sink().template connect<&Registry::creating<Component...>>();
                 std::get<2>(cpool).sink().template connect<&Registry::destroying<Component...>>();
@@ -1308,7 +1308,7 @@ public:
         if(contains<Component...>()) {
             const auto htype = handler_family::type<Component...>();
 
-            auto disconnect = [this](auto ctype) {
+            auto disconnect = [this](const auto ctype) {
                 auto &cpool = pools[ctype];
                 std::get<1>(cpool).sink().template disconnect<&Registry::creating<Component...>>();
                 std::get<2>(cpool).sink().template disconnect<&Registry::destroying<Component...>>();
@@ -1418,10 +1418,10 @@ public:
      * @return A temporary object to use to take snasphosts.
      */
     Snapshot<Entity> snapshot() const {
-        using follow_fn_type = entity_type(*)(const Registry &, entity_type);
+        using follow_fn_type = entity_type(*)(const Registry &, const entity_type);
         const entity_type seed = available ? (next | (entities[next] & ~traits_type::entity_mask)) : next;
 
-        follow_fn_type follow = [](const Registry &registry, entity_type entity) -> entity_type {
+        follow_fn_type follow = [](const Registry &registry, const entity_type entity) -> entity_type {
             const auto &entities = registry.entities;
             const auto entt = entity & traits_type::entity_mask;
             const auto next = entities[entt] & traits_type::entity_mask;
@@ -1447,9 +1447,9 @@ public:
      * @return A temporary object to use to load snasphosts.
      */
     SnapshotLoader<Entity> restore() {
-        using assure_fn_type = void(*)(Registry &, entity_type, bool);
+        using assure_fn_type = void(*)(Registry &, const entity_type, const bool);
 
-        assure_fn_type assure = [](Registry &registry, entity_type entity, bool destroyed) {
+        assure_fn_type assure = [](Registry &registry, const entity_type entity, const bool destroyed) {
             using promotion_type = std::conditional_t<sizeof(size_type) >= sizeof(entity_type), size_type, entity_type>;
             // explicit promotion to avoid warnings with std::uint16_t
             const auto entt = promotion_type{entity} & traits_type::entity_mask;

src/entt/entity/snapshot.hpp

@@ -39,7 +39,7 @@ class Snapshot final {
     /*! @brief A registry is allowed to create snapshots. */
     friend class Registry<Entity>;
 
-    using follow_fn_type = Entity(*)(const Registry<Entity> &, Entity);
+    using follow_fn_type = Entity(*)(const Registry<Entity> &, const Entity);
 
     Snapshot(const Registry<Entity> &registry, Entity seed, std::size_t size, follow_fn_type follow) ENTT_NOEXCEPT
         : registry{registry},
@@ -99,7 +99,7 @@ public:
     template<typename Archive>
     Snapshot & entities(Archive &archive) {
         archive(static_cast<Entity>(registry.size()));
-        registry.each([&archive](auto entity) { archive(entity); });
+        registry.each([&archive](const auto entity) { archive(entity); });
         return *this;
     }
 
@@ -191,7 +191,7 @@ class SnapshotLoader final {
     /*! @brief A registry is allowed to create snapshot loaders. */
     friend class Registry<Entity>;
 
-    using assure_fn_type = void(*)(Registry<Entity> &, Entity, bool);
+    using assure_fn_type = void(*)(Registry<Entity> &, const Entity, const bool);
 
     SnapshotLoader(Registry<Entity> &registry, assure_fn_type assure_fn) ENTT_NOEXCEPT
         : registry{registry},
@@ -216,7 +216,7 @@ class SnapshotLoader final {
 
     template<typename Type, typename Archive, typename... Args>
     void assign(Archive &archive, Args... args) {
-        each(archive, [&archive, this, args...](auto entity) {
+        each(archive, [&archive, this, args...](const auto entity) {
             static constexpr auto destroyed = false;
             assure_fn(registry, entity, destroyed);
             archive(registry.template assign<Type>(args..., entity));
@@ -246,7 +246,7 @@ public:
      */
     template<typename Archive>
     SnapshotLoader & entities(Archive &archive) {
-        each(archive, [this](auto entity) {
+        each(archive, [this](const auto entity) {
             static constexpr auto destroyed = false;
             assure_fn(registry, entity, destroyed);
         });
@@ -266,7 +266,7 @@ public:
      */
     template<typename Archive>
     SnapshotLoader & destroyed(Archive &archive) {
-        each(archive, [this](auto entity) {
+        each(archive, [this](const auto entity) {
             static constexpr auto destroyed = true;
             assure_fn(registry, entity, destroyed);
         });
@@ -327,7 +327,7 @@ public:
      * @return A valid loader to continue restoring data.
      */
     SnapshotLoader & orphans() {
-        registry.orphans([this](auto entity) {
+        registry.orphans([this](const auto entity) {
             registry.destroy(entity);
         });
 
@@ -360,7 +360,7 @@ template<typename Entity>
 class ContinuousLoader final {
     using traits_type = entt_traits<Entity>;
 
-    Entity destroy(Entity entity) {
+    Entity destroy(const Entity entity) {
         const auto it = remloc.find(entity);
 
         if(it == remloc.cend()) {
@@ -372,7 +372,7 @@ class ContinuousLoader final {
         return remloc[entity].first;
     }
 
-    Entity restore(Entity entity) {
+    Entity restore(const Entity entity) {
         const auto it = remloc.find(entity);
 
         if(it == remloc.cend()) {
@@ -433,9 +433,9 @@ class ContinuousLoader final {
     void assign(Archive &archive) {
         reset<Component>();
 
-        each(archive, [&archive, this](auto entity) {
-            entity = restore(entity);
-            archive(registry.template accommodate<Component>(entity));
+        each(archive, [&archive, this](const auto entity) {
+            const auto local = restore(entity);
+            archive(registry.template accommodate<Component>(local));
         });
     }
 
@@ -443,9 +443,9 @@ class ContinuousLoader final {
     void assign(Archive &archive, Type Component::*... member) {
         reset<Component>();
 
-        each(archive, [&archive, member..., this](auto entity) {
-            entity = restore(entity);
-            auto &component = registry.template accommodate<Component>(entity);
+        each(archive, [&archive, member..., this](const auto entity) {
+            const auto local = restore(entity);
+            auto &component = registry.template accommodate<Component>(local);
             archive(component);
 
             using accumulator_type = int[];
@@ -458,9 +458,9 @@ class ContinuousLoader final {
     void attach(Archive &archive) {
         registry.template remove<Tag>();
 
-        each(archive, [&archive, this](auto entity) {
-            entity = restore(entity);
-            archive(registry.template assign<Tag>(tag_t{}, entity));
+        each(archive, [&archive, this](const auto entity) {
+            const auto local = restore(entity);
+            archive(registry.template assign<Tag>(tag_t{}, local));
         });
     }
 
@@ -468,9 +468,9 @@ class ContinuousLoader final {
     void attach(Archive &archive, Type Tag::*... member) {
         registry.template remove<Tag>();
 
-        each(archive, [&archive, member..., this](auto entity) {
-            entity = restore(entity);
-            auto &tag = registry.template assign<Tag>(tag_t{}, entity);
+        each(archive, [&archive, member..., this](const auto entity) {
+            const auto local = restore(entity);
+            auto &tag = registry.template assign<Tag>(tag_t{}, local);
             archive(tag);
 
             using accumulator_type = int[];
@@ -513,7 +513,7 @@ public:
      */
     template<typename Archive>
     ContinuousLoader & entities(Archive &archive) {
-        each(archive, [this](auto entity) { restore(entity); });
+        each(archive, [this](const auto entity) { restore(entity); });
         return *this;
     }
 
@@ -529,7 +529,7 @@ public:
      */
     template<typename Archive>
     ContinuousLoader & destroyed(Archive &archive) {
-        each(archive, [this](auto entity) { destroy(entity); });
+        each(archive, [this](const auto entity) { destroy(entity); });
         return *this;
     }
 
@@ -664,7 +664,7 @@ public:
      * @return A non-const reference to this loader.
      */
     ContinuousLoader & orphans() {
-        registry.orphans([this](auto entity) {
+        registry.orphans([this](const auto entity) {
             registry.destroy(entity);
         });
 

src/entt/entity/sparse_set.hpp

@@ -79,12 +79,12 @@ class SparseSet<Entity> {
             return ++(*this), orig;
         }
 
-        Iterator & operator+=(difference_type value) ENTT_NOEXCEPT {
+        Iterator & operator+=(const difference_type value) ENTT_NOEXCEPT {
             pos -= value;
             return *this;
         }
 
-        Iterator operator+(difference_type value) const ENTT_NOEXCEPT {
+        Iterator operator+(const difference_type value) const ENTT_NOEXCEPT {
             return Iterator{direct, pos-value};
         }
 
@@ -143,7 +143,7 @@ public:
      *
      * @param cap Desired capacity.
      */
-    void reserve(size_type cap) {
+    void reserve(const size_type cap) {
         direct.reserve(cap);
     }
 
@@ -264,7 +264,7 @@ public:
      * internal packed array.
      */
     const_iterator_type cend() const ENTT_NOEXCEPT {
-        return const_iterator_type{direct.data(), 0};
+        return const_iterator_type{direct.data(), {}};
     }
 
     /**
@@ -306,7 +306,7 @@ public:
      * @param entity A valid entity identifier.
      * @return True if the sparse set contains the entity, false otherwise.
      */
-    bool has(entity_type entity) const ENTT_NOEXCEPT {
+    bool has(const entity_type entity) const ENTT_NOEXCEPT {
         const auto pos = size_type(entity & traits_type::entity_mask);
         // testing against pending permits to avoid accessing the direct vector
         return (pos < reverse.size()) && (reverse[pos] != pending);
@@ -329,7 +329,7 @@ public:
      * @param entity A valid entity identifier.
      * @return True if the sparse set contains the entity, false otherwise.
      */
-    bool fast(entity_type entity) const ENTT_NOEXCEPT {
+    bool fast(const entity_type entity) const ENTT_NOEXCEPT {
         const auto pos = size_type(entity & traits_type::entity_mask);
         assert(pos < reverse.size());
         // testing against pending permits to avoid accessing the direct vector
@@ -348,7 +348,7 @@ public:
      * @param entity A valid entity identifier.
      * @return The position of the entity in the sparse set.
      */
-    pos_type get(entity_type entity) const ENTT_NOEXCEPT {
+    pos_type get(const entity_type entity) const ENTT_NOEXCEPT {
         assert(has(entity));
         return reverse[entity & traits_type::entity_mask];
     }
@@ -364,7 +364,7 @@ public:
      *
      * @param entity A valid entity identifier.
      */
-    void construct(entity_type entity) {
+    void construct(const entity_type entity) {
         assert(!has(entity));
         const auto pos = size_type(entity & traits_type::entity_mask);
 
@@ -388,7 +388,7 @@ public:
      *
      * @param entity A valid entity identifier.
      */
-    virtual void destroy(entity_type entity) {
+    virtual void destroy(const entity_type entity) {
         assert(has(entity));
         const auto back = direct.back();
         auto &candidate = reverse[entity & traits_type::entity_mask];
@@ -414,7 +414,7 @@ public:
      * @param lhs A valid position within the sparse set.
      * @param rhs A valid position within the sparse set.
      */
-    void swap(pos_type lhs, pos_type rhs) ENTT_NOEXCEPT {
+    void swap(const pos_type lhs, const pos_type rhs) ENTT_NOEXCEPT {
         assert(lhs < direct.size());
         assert(rhs < direct.size());
         auto &src = direct[lhs];
@@ -522,12 +522,12 @@ class SparseSet<Entity, Type>: public SparseSet<Entity> {
             return ++(*this), orig;
         }
 
-        Iterator & operator+=(difference_type value) ENTT_NOEXCEPT {
+        Iterator & operator+=(const difference_type value) ENTT_NOEXCEPT {
             pos -= value;
             return *this;
         }
 
-        Iterator operator+(difference_type value) const ENTT_NOEXCEPT {
+        Iterator operator+(const difference_type value) const ENTT_NOEXCEPT {
             return Iterator{instances, pos-value};
         }
 
@@ -587,7 +587,7 @@ public:
      *
      * @param cap Desired capacity.
      */
-    void reserve(size_type cap) {
+    void reserve(const size_type cap) {
         underlying_type::reserve(cap);
         instances.reserve(cap);
     }
@@ -693,7 +693,7 @@ public:
      * given type.
      */
     const_iterator_type cend() const ENTT_NOEXCEPT {
-        return const_iterator_type{instances.data(), 0};
+        return const_iterator_type{instances.data(), {}};
     }
 
     /**
@@ -729,7 +729,7 @@ public:
      * given type.
      */
     iterator_type end() ENTT_NOEXCEPT {
-        return iterator_type{instances.data(), 0};
+        return iterator_type{instances.data(), {}};
     }
 
     /**
@@ -744,7 +744,7 @@ public:
      * @param entity A valid entity identifier.
      * @return The object associated to the entity.
      */
-    const object_type & get(entity_type entity) const ENTT_NOEXCEPT {
+    const object_type & get(const entity_type entity) const ENTT_NOEXCEPT {
         return instances[underlying_type::get(entity)];
     }
 
@@ -760,7 +760,7 @@ public:
      * @param entity A valid entity identifier.
      * @return The object associated to the entity.
      */
-    inline object_type & get(entity_type entity) ENTT_NOEXCEPT {
+    inline object_type & get(const entity_type entity) ENTT_NOEXCEPT {
         return const_cast<object_type &>(const_cast<const SparseSet *>(this)->get(entity));
     }
 
@@ -786,7 +786,7 @@ public:
      */
     template<typename... Args>
     std::enable_if_t<std::is_constructible<Type, Args...>::value, object_type &>
-    construct(entity_type entity, Args &&... args) {
+    construct(const entity_type entity, Args &&... args) {
         underlying_type::construct(entity);
         instances.emplace_back(std::forward<Args>(args)...);
         return instances.back();
@@ -814,7 +814,7 @@ public:
      */
     template<typename... Args>
     std::enable_if_t<!std::is_constructible<Type, Args...>::value, object_type &>
-    construct(entity_type entity, Args &&... args) {
+    construct(const entity_type entity, Args &&... args) {
         underlying_type::construct(entity);
         instances.emplace_back(Type{std::forward<Args>(args)...});
         return instances.back();
@@ -831,7 +831,7 @@ public:
      *
      * @param entity A valid entity identifier.
      */
-    void destroy(entity_type entity) override {
+    void destroy(const entity_type entity) override {
         // swapping isn't required here, we are getting rid of the last element
         // however, we must protect ourselves from self assignments (see #37)
         auto tmp = std::move(instances.back());
@@ -884,7 +884,7 @@ public:
         std::vector<pos_type> copy(instances.size());
         std::iota(copy.begin(), copy.end(), 0);
 
-        sort(copy.begin(), copy.end(), [this, compare = std::move(compare)](auto lhs, auto rhs) {
+        sort(copy.begin(), copy.end(), [this, compare = std::move(compare)](const auto lhs, const auto rhs) {
             return compare(const_cast<const object_type &>(instances[rhs]), const_cast<const object_type &>(instances[lhs]));
         });
 

src/entt/entity/view.hpp

@@ -239,7 +239,7 @@ public:
      * @param entity A valid entity identifier.
      * @return True if the view contains the given entity, false otherwise.
      */
-    bool contains(entity_type entity) const ENTT_NOEXCEPT {
+    bool contains(const entity_type entity) const ENTT_NOEXCEPT {
         return view.has(entity) && (view.data()[view.get(entity)] == entity);
     }
 
@@ -261,7 +261,7 @@ public:
      * @return The component assigned to the entity.
      */
     template<typename Comp>
-    const Comp & get(entity_type entity) const ENTT_NOEXCEPT {
+    const Comp & get(const entity_type entity) const ENTT_NOEXCEPT {
         assert(contains(entity));
         return std::get<pool_type<Comp> &>(pools).get(entity);
     }
@@ -284,7 +284,7 @@ public:
      * @return The component assigned to the entity.
      */
     template<typename Comp>
-    inline Comp & get(entity_type entity) ENTT_NOEXCEPT {
+    inline Comp & get(const entity_type entity) ENTT_NOEXCEPT {
         return const_cast<Comp &>(const_cast<const PersistentView *>(this)->get<Comp>(entity));
     }
 
@@ -307,7 +307,7 @@ public:
      */
     template<typename... Comp>
     std::enable_if_t<(sizeof...(Comp) > 1), std::tuple<const Comp &...>>
-    get(entity_type entity) const ENTT_NOEXCEPT {
+    get(const entity_type entity) const ENTT_NOEXCEPT {
         assert(contains(entity));
         return std::tuple<const Comp &...>{get<Comp>(entity)...};
     }
@@ -331,7 +331,7 @@ public:
      */
     template<typename... Comp>
     std::enable_if_t<(sizeof...(Comp) > 1), std::tuple<Comp &...>>
-    get(entity_type entity) ENTT_NOEXCEPT {
+    get(const entity_type entity) ENTT_NOEXCEPT {
         assert(contains(entity));
         return std::tuple<Comp &...>{get<Comp>(entity)...};
     }
@@ -346,7 +346,7 @@ public:
      * The signature of the function should be equivalent to the following:
      *
      * @code{.cpp}
-     * void(entity_type, const Component &...);
+     * void(const entity_type, const Component &...);
      * @endcode
      *
      * @tparam Func Type of the function object to invoke.
@@ -369,7 +369,7 @@ public:
      * The signature of the function should be equivalent to the following:
      *
      * @code{.cpp}
-     * void(entity_type, Component &...);
+     * void(const entity_type, Component &...);
      * @endcode
      *
      * @tparam Func Type of the function object to invoke.
@@ -377,7 +377,7 @@ public:
      */
     template<typename Func>
     inline void each(Func func) {
-        const_cast<const PersistentView *>(this)->each([&func](entity_type entity, const Component &... component) {
+        const_cast<const PersistentView *>(this)->each([&func](const entity_type entity, const Component &... component) {
             func(entity, const_cast<Component &>(component)...);
         });
     }
@@ -507,11 +507,11 @@ class View final {
             return ++(*this), orig;
         }
 
-        Iterator & operator+=(difference_type value) ENTT_NOEXCEPT {
+        Iterator & operator+=(const difference_type value) ENTT_NOEXCEPT {
             return ((begin += value) != end && !valid()) ? ++(*this) : *this;
         }
 
-        Iterator operator+(difference_type value) const ENTT_NOEXCEPT {
+        Iterator operator+(const difference_type value) const ENTT_NOEXCEPT {
             return Iterator{unchecked, extent, begin+value, end};
         }
 
@@ -569,11 +569,11 @@ class View final {
 
     template<typename Comp, typename Other>
     inline std::enable_if_t<std::is_same<Comp, Other>::value, const Other &>
-    get(const component_iterator_type<Comp> &it, Entity) const ENTT_NOEXCEPT { return *it; }
+    get(const component_iterator_type<Comp> &it, const Entity) const ENTT_NOEXCEPT { return *it; }
 
     template<typename Comp, typename Other>
     inline std::enable_if_t<!std::is_same<Comp, Other>::value, const Other &>
-    get(const component_iterator_type<Comp> &, Entity entity) const ENTT_NOEXCEPT { return pool<Other>().get(entity); }
+    get(const component_iterator_type<Comp> &, const Entity entity) const ENTT_NOEXCEPT { return pool<Other>().get(entity); }
 
     template<typename Comp, typename Func, std::size_t... Indexes>
     void each(const pool_type<Comp> &cpool, Func func, std::index_sequence<Indexes...>) const {
@@ -751,7 +751,7 @@ public:
      * @param entity A valid entity identifier.
      * @return True if the view contains the given entity, false otherwise.
      */
-    bool contains(entity_type entity) const ENTT_NOEXCEPT {
+    bool contains(const entity_type entity) const ENTT_NOEXCEPT {
         const auto sz = size_type(entity & traits_type::entity_mask);
         return sz < extent() && std::min({ (pool<Component>().has(entity) && (pool<Component>().data()[pool<Component>().view_type::get(entity)] == entity))... });
     }
@@ -774,7 +774,7 @@ public:
      * @return The component assigned to the entity.
      */
     template<typename Comp>
-    const Comp & get(entity_type entity) const ENTT_NOEXCEPT {
+    const Comp & get(const entity_type entity) const ENTT_NOEXCEPT {
         assert(contains(entity));
         return pool<Comp>().get(entity);
     }
@@ -797,7 +797,7 @@ public:
      * @return The component assigned to the entity.
      */
     template<typename Comp>
-    inline Comp & get(entity_type entity) ENTT_NOEXCEPT {
+    inline Comp & get(const entity_type entity) ENTT_NOEXCEPT {
         return const_cast<Comp &>(const_cast<const View *>(this)->get<Comp>(entity));
     }
 
@@ -820,7 +820,7 @@ public:
      */
     template<typename... Comp>
     std::enable_if_t<(sizeof...(Comp) > 1), std::tuple<const Comp &...>>
-    get(entity_type entity) const ENTT_NOEXCEPT {
+    get(const entity_type entity) const ENTT_NOEXCEPT {
         assert(contains(entity));
         return std::tuple<const Comp &...>{get<Comp>(entity)...};
     }
@@ -844,7 +844,7 @@ public:
      */
     template<typename... Comp>
     std::enable_if_t<(sizeof...(Comp) > 1), std::tuple<Comp &...>>
-    get(entity_type entity) ENTT_NOEXCEPT {
+    get(const entity_type entity) ENTT_NOEXCEPT {
         assert(contains(entity));
         return std::tuple<Comp &...>{get<Comp>(entity)...};
     }
@@ -859,7 +859,7 @@ public:
      * The signature of the function should be equivalent to the following:
      *
      * @code{.cpp}
-     * void(entity_type, const Component &...);
+     * void(const entity_type, const Component &...);
      * @endcode
      *
      * @tparam Func Type of the function object to invoke.
@@ -883,7 +883,7 @@ public:
      * The signature of the function should be equivalent to the following:
      *
      * @code{.cpp}
-     * void(entity_type, Component &...);
+     * void(const entity_type, Component &...);
      * @endcode
      *
      * @tparam Func Type of the function object to invoke.
@@ -891,7 +891,7 @@ public:
      */
     template<typename Func>
     inline void each(Func func) {
-        const_cast<const View *>(this)->each([&func](entity_type entity, const Component &... component) {
+        const_cast<const View *>(this)->each([&func](const entity_type entity, const Component &... component) {
             func(entity, const_cast<Component &>(component)...);
         });
     }
@@ -1142,7 +1142,7 @@ public:
      * @param entity A valid entity identifier.
      * @return True if the view contains the given entity, false otherwise.
      */
-    bool contains(entity_type entity) const ENTT_NOEXCEPT {
+    bool contains(const entity_type entity) const ENTT_NOEXCEPT {
         return pool.has(entity) && (pool.data()[pool.view_type::get(entity)] == entity);
     }
 
@@ -1161,7 +1161,7 @@ public:
      * @param entity A valid entity identifier.
      * @return The component assigned to the entity.
      */
-    const Component & get(entity_type entity) const ENTT_NOEXCEPT {
+    const Component & get(const entity_type entity) const ENTT_NOEXCEPT {
         assert(contains(entity));
         return pool.get(entity);
     }
@@ -1181,7 +1181,7 @@ public:
      * @param entity A valid entity identifier.
      * @return The component assigned to the entity.
      */
-    inline Component & get(entity_type entity) ENTT_NOEXCEPT {
+    inline Component & get(const entity_type entity) ENTT_NOEXCEPT {
         return const_cast<Component &>(const_cast<const View *>(this)->get(entity));
     }
 
@@ -1194,7 +1194,7 @@ public:
      * The signature of the function should be equivalent to the following:
      *
      * @code{.cpp}
-     * void(entity_type, const Component &);
+     * void(const entity_type, const Component &);
      * @endcode
      *
      * @tparam Func Type of the function object to invoke.
@@ -1216,7 +1216,7 @@ public:
      * The signature of the function should be equivalent to the following:
      *
      * @code{.cpp}
-     * void(entity_type, Component &);
+     * void(const entity_type, Component &);
      * @endcode
      *
      * @tparam Func Type of the function object to invoke.
@@ -1224,7 +1224,7 @@ public:
      */
     template<typename Func>
     inline void each(Func func) {
-        const_cast<const View *>(this)->each([&func](entity_type entity, const Component &component) {
+        const_cast<const View *>(this)->each([&func](const entity_type entity, const Component &component) {
             func(entity, const_cast<Component &>(component));
         });
     }

src/entt/process/process.hpp

@@ -183,7 +183,7 @@ public:
      *
      * @param immediately Requests an immediate operation.
      */
-    void abort(bool immediately = false) ENTT_NOEXCEPT {
+    void abort(const bool immediately = false) ENTT_NOEXCEPT {
         if(alive()) {
             current = State::ABORTED;
 
@@ -230,7 +230,7 @@ public:
      * @param delta Elapsed time.
      * @param data Optional data.
      */
-    void tick(Delta delta, void *data = nullptr) {
+    void tick(const Delta delta, void *data = nullptr) {
         switch (current) {
         case State::UNINITIALIZED:
             tick(0, tag<State::UNINITIALIZED>{}, data);
@@ -327,7 +327,7 @@ struct ProcessAdaptor: Process<ProcessAdaptor<Func, Delta>, Delta>, private Func
      * @param delta Elapsed time.
      * @param data Optional data.
      */
-    void update(Delta delta, void *data) {
+    void update(const Delta delta, void *data) {
         Func::operator()(delta, data, [this]() { this->succeed(); }, [this]() { this->fail(); });
     }
 };

src/entt/process/scheduler.hpp

@@ -82,7 +82,7 @@ class Scheduler final {
     };
 
     template<typename Proc>
-    static bool update(ProcessHandler &handler, Delta delta, void *data) {
+    static bool update(ProcessHandler &handler, const Delta delta, void *data) {
         auto *process = static_cast<Proc *>(handler.instance.get());
         process->tick(delta, data);
 
@@ -101,7 +101,7 @@ class Scheduler final {
     }
 
     template<typename Proc>
-    static void abort(ProcessHandler &handler, bool immediately) {
+    static void abort(ProcessHandler &handler, const bool immediately) {
         static_cast<Proc *>(handler.instance.get())->abort(immediately);
     }
 
@@ -272,7 +272,7 @@ public:
      * @param delta Elapsed time.
      * @param data Optional data.
      */
-    void update(Delta delta, void *data = nullptr) {
+    void update(const Delta delta, void *data = nullptr) {
         bool clean = false;
 
         for(auto pos = handlers.size(); pos; --pos) {
@@ -298,7 +298,7 @@ public:
      *
      * @param immediately Requests an immediate operation.
      */
-    void abort(bool immediately = false) {
+    void abort(const bool immediately = false) {
         decltype(handlers) exec;
         exec.swap(handlers);
 

src/entt/resource/cache.hpp

@@ -93,7 +93,7 @@ public:
      * @return True if the resource is ready to use, false otherwise.
      */
     template<typename Loader, typename... Args>
-    bool load(resource_type id, Args &&... args) {
+    bool load(const resource_type id, Args &&... args) {
         static_assert(std::is_base_of<ResourceLoader<Loader, Resource>, Loader>::value, "!");
 
         bool loaded = true;
@@ -126,7 +126,7 @@ public:
      * @return True if the resource is ready to use, false otherwise.
      */
     template<typename Loader, typename... Args>
-    bool reload(resource_type id, Args &&... args) {
+    bool reload(const resource_type id, Args &&... args) {
         return (discard(id), load<Loader>(id, std::forward<Args>(args)...));
     }
 
@@ -160,7 +160,7 @@ public:
      * @param id Unique resource identifier.
      * @return A handle for the given resource.
      */
-    ResourceHandle<Resource> handle(resource_type id) const {
+    ResourceHandle<Resource> handle(const resource_type id) const {
         auto it = resources.find(id);
         return { it == resources.end() ? nullptr : it->second };
     }
@@ -170,7 +170,7 @@ public:
      * @param id Unique resource identifier.
      * @return True if the cache contains the resource, false otherwise.
      */
-    bool contains(resource_type id) const ENTT_NOEXCEPT {
+    bool contains(const resource_type id) const ENTT_NOEXCEPT {
         return (resources.find(id) != resources.cend());
     }
 
@@ -182,7 +182,7 @@ public:
      *
      * @param id Unique resource identifier.
      */
-    void discard(resource_type id) ENTT_NOEXCEPT {
+    void discard(const resource_type id) ENTT_NOEXCEPT {
         auto it = resources.find(id);
 
         if(it != resources.end()) {

src/entt/resource/handle.hpp

@@ -70,7 +70,7 @@ public:
      * An assertion will abort the execution at runtime in debug mode if the
      * handle is empty.
      */
-    inline operator const Resource & () const ENTT_NOEXCEPT { return get(); }
+    inline operator const Resource &() const ENTT_NOEXCEPT { return get(); }
 
     /**
      * @brief Dereferences a handle to obtain the managed resource.

test/entt/entity/sparse_set.cpp

@@ -271,7 +271,6 @@ TEST(SparseSetWithType, Functionalities) {
 
     set.construct(42, 3);
 
-    ASSERT_EQ(set.get(42), 3);
     ASSERT_FALSE(set.empty());
     ASSERT_EQ(set.size(), 1u);
     ASSERT_NE(cset.begin(), cset.end());

test/mod/mod.cpp

@@ -135,7 +135,6 @@ duk_ret_t get<DuktapeRuntime>(duk_context *ctx, entt::DefaultRegistry &registry)
     duk_push_string(ctx, runtime.components[type].c_str());
     duk_json_decode(ctx, -1);
 
-
     return 1;
 }