The article does mention this, but only very briefly and only gives one of the two solutions without much explanation behind and it isn't exactly easy to find it in the article even if you know what you are looking for. Search for deleter in part 2 of the article to find it.
Re: Modern C++ for C Programmers: part 5
#81That SmartFP class is not safe to use, it doesn't implement or block the copy constructor so you might get two objects pointing to the same FILE*. (rule of five vs rule of zero)