storage: reintroduce support to args for empty types - see #1323

src/entt/entity/registry.hpp

@@ -571,21 +571,6 @@ public:
         return assure<Type>().emplace(entt, std::forward<Args>(args)...);
     }
 
-    /**
-     * @brief Assigns each entity in a range the given element.
-     *
-     * @sa emplace
-     *
-     * @tparam Type Type of element to create.
-     * @param first An iterator to the first element of the range of entities.
-     * @param last An iterator past the last element of the range of entities.
-     */
-    template<typename Type>
-    void insert(stl::input_iterator auto first, stl::input_iterator auto last) {
-        ENTT_ASSERT(std::all_of(first, last, [this](const auto entt) { return valid(entt); }), "Invalid entity");
-        assure<Type>().insert(std::move(first), std::move(last));
-    }
-
     /**
      * @brief Assigns each entity in a range the given element.
      *
@@ -597,7 +582,7 @@ public:
      * @param value An instance of the element to assign.
      */
     template<typename Type>
-    void insert(stl::input_iterator auto first, stl::input_iterator auto last, const Type &value) {
+    void insert(stl::input_iterator auto first, stl::input_iterator auto last, const Type &value = {}) {
         ENTT_ASSERT(std::all_of(first, last, [this](const auto entt) { return valid(entt); }), "Invalid entity");
         assure<Type>().insert(std::move(first), std::move(last), value);
     }

src/entt/entity/storage.hpp

@@ -890,9 +890,12 @@ public:
      * Attempting to use an entity that already belongs to the storage results
      * in undefined behavior.
      *
+     * @tparam Args Types of arguments to use to construct the object.
      * @param entt A valid identifier.
      */
-    void emplace(const entity_type entt) {
+    template<typename... Args>
+    // NOLINTNEXTLINE(cppcoreguidelines-missing-std-forward)
+    auto emplace(const entity_type entt, Args &&...) {
         base_type::try_emplace(entt, false);
     }
 
@@ -911,11 +914,13 @@ public:
     /**
      * @brief Assigns entities to a storage.
      * @tparam It Type of input iterator.
+     * @tparam Args Types of optional arguments.
      * @param first An iterator to the first element of the range of entities.
      * @param last An iterator past the last element of the range of entities.
      */
-    template<stl::input_iterator It>
-    void insert(It first, It last) {
+    template<typename It, typename... Args>
+    // NOLINTNEXTLINE(cppcoreguidelines-missing-std-forward)
+    void insert(It first, It last, Args &&...) {
         for(; first != last; ++first) {
             base_type::try_emplace(*first, true);
         }