base class 'class std::vector<...>' has a non-virtual destructor

Question

One of my C++ classes derives from std::vector so that it can act as a container that also perform custom actions on its content. Unfortunately, the compiler complains about the destructor not to be virtual, which I cannot change, since its in the standard library.

Am I doing the whole thing wrong (thou shall not derive from STL) or is there something I could do to keep the compiler happy ? (appart from stop using -Weffc++ :)

edit: the derived class do not touch the vector-manipulation algorithms, but merely add some information such as "element width/height" for a vector of images. As an example, you could think of

class PhotoAlbum: public std::vector<Photo> {
    String title;
    Date from_time, to_time;
    // accessors for title and dates
    void renderCover(Drawable &surface);
};

where you think of a photo album primarily as a collection of pictures with some meta-data (title and time) and album-specific features such as rendering a thumbnail of some Photo onto a surface to make the album cover. So imho, the photo album IS-A collection of Photo, more than it HAS-A such collection.

I fail to see any benefit I'd gain of having getPhotoVector() method in a PhotoAlbum that would have an extra "collection" field.

Answer 1

Why not use composition? Simply make std::vector a member of your custom container, then implement the custom actions as member functions of said class that act upon the std::vector member. That way, you have complete control over it. Besides, you should prefer composition over inheritance if inheritance is not required.