Method operator()

extlibs/sol3/include/sol/sol.hpp:21230–21238

		change_indexing_mem_func change_indexing;

		void operator()(lua_State* L, submetatable_type smt, reference& fast_index_table) {
			int fast_index_table_push = fast_index_table.push();
			stack_reference t(L, -fast_index_table_push);
			stack::set_field(L, detail::base_class_check_key(), reinterpret_cast<void*>(base_class_check_func), t.stack_index());
			stack::set_field(L, detail::base_class_cast_key(), reinterpret_cast<void*>(base_class_cast_func), t.stack_index());
			// change indexing, forcefully
			(p_usb->*change_indexing)(L, smt, p_derived_usb, t, idx_call, new_idx_call, meta_idx_call, meta_new_idx_call);
			t.pop();
		}
	};

	struct binding_data_equals {