registry: ::remove requires at least a component now (close #623)

src/entt/entity/registry.hpp

@@ -716,6 +716,7 @@ public:
     template<typename... Component>
     void remove(const entity_type entity) {
         ENTT_ASSERT(valid(entity));
+        static_assert(sizeof...(Component) > 0);
         (assure<Component>()->remove(*this, entity), ...);
     }
 
@@ -732,6 +733,7 @@ public:
     template<typename... Component, typename It>
     void remove(It first, It last) {
         ENTT_ASSERT(std::all_of(first, last, [this](const auto entity) { return valid(entity); }));
+        static_assert(sizeof...(Component) > 0);
         (assure<Component>()->remove(*this, first, last), ...);
     }