Function default_traceback_error_handler

Libs/sol/sol.hpp:24949–24968

	}

	inline int default_traceback_error_handler(lua_State* L) {
		std::string msg = "An unknown error has triggered the default error handler";
		optional<string_view> maybetopmsg = stack::unqualified_check_get<string_view>(L, 1, no_panic);
		if (maybetopmsg) {
			const string_view& topmsg = maybetopmsg.value();
			msg.assign(topmsg.data(), topmsg.size());
		}
		luaL_traceback(L, L, msg.c_str(), 1);
		optional<string_view> maybetraceback = stack::unqualified_check_get<string_view>(L, -1, no_panic);
		if (maybetraceback) {
			const string_view& traceback = maybetraceback.value();
			msg.assign(traceback.data(), traceback.size());
		}
#if SOL_IS_ON(SOL_PRINT_ERRORS_I_)
		// std::cerr << "[sol3] An error occurred and was caught in traceback: ";
		// std::cerr << msg;
		// std::cerr << std::endl;
#endif // Printing
		return stack::push(L, msg);
	}

	inline void set_default_state(lua_State* L, lua_CFunction panic_function = &default_at_panic,
	     lua_CFunction traceback_function = c_call<decltype(&default_traceback_error_handler), &default_traceback_error_handler>,