PyErr_SetString的字符串参数:它被借用了吗?

PyErr_SetString如何处理传入的c字符串?例如,这样做是否安全:

{
  int age = 12;
  std::stringstream ostr; ostr << "I'm " << age << " years old and what is this?";
  PyErr_SetString(PyExc_RuntimeError, ostr.str().c_str());
}

明显地 https://docs.python.org/2/c-api/exceptions.html#PyErr_SetString 表示它“转换为字符串对象”,但这是否必然意味着内容将被复制?