checking for empty in trivial system removes

Author: zaucy

ecsact/entt/trivial_system_impl.hh

@@ -92,11 +92,13 @@ void trivial_system_impl(
 			if constexpr(!C::transient) {
 				info.registry.template emplace<component_removed<C>>(entity);
 
-				auto& temp = info.registry.template storage<temp_storage<C>>();
-				if(temp.contains(entity)) {
-					temp.get(entity).value = info.registry.template get<C>(entity);
-				} else {
-					temp.emplace(entity, info.registry.template get<C>(entity));
+				if constexpr(!std::is_empty_v<C>) {
+					auto& temp = info.registry.template storage<temp_storage<C>>();
+					if(temp.contains(entity)) {
+						temp.get(entity).value = info.registry.template get<C>(entity);
+					} else {
+						temp.emplace(entity, info.registry.template get<C>(entity));
+					}
 				}
 			}
 		});

runtime/test/runtime_test.cc

@@ -37,6 +37,14 @@ void runtime_test::TrivialRemove::impl(context& ctx) {
 	std::abort();
 }
 
+void runtime_test::AlwaysRemove::impl(context& ctx) {
+	// This trivial remove should not even be required:
+	// SEE: https://github.com/ecsact-dev/ecsact_lang_cpp/issues/80
+	std::cerr << "AlwaysRemove impl called (SHOULD NOT HAPPEN)\n";
+	std::cerr.flush();
+	std::abort();
+}
+
 TEST(Core, CreateRegistry) {
 	auto reg_id = ecsact_create_registry("CreateRegistry");
 	EXPECT_NE(reg_id, ecsact_invalid_registry_id);

runtime/test/runtime_test.ecsact

@@ -11,6 +11,8 @@ component OtherEntityComponent {
 
 component EmptyComponent;
 
+component AlwaysRemoveMe;
+
 system SimpleSystem {
 	readwrite ComponentA;
 }
@@ -28,6 +30,10 @@ system OtherEntitySystem {
 	}
 }
 
+system AlwaysRemove {
+	removes AlwaysRemoveMe;
+}
+
 action MakeAnother {
 	readwrite ComponentA;
 	generates {