Question

I have MyClass that hide the container inside it, I want to control when new item is added to the container and when an item is to be deleted from container, but i don’t need to control read-only operation such as getter function

class MyClass {
    protected: 
        std::vector<MySubClass> subclasses;
    public:
}

for interfacing with the user of MyClass, should I implement interface function such as :

addSubClass(), getSubClassAt(int ), getSubClassIndex(MySubclass ), delSubClass().

or its better just return const iterator, for readonly operation :

std::vector<MySubClass>::const_iterator getSubclassIterator();

and provide special write-operation function such as

addSubClass(), delSubClass().

or is there is a better way than these?

Answer 1

If you invent your own member functions for manipulating the internal list of objects, then I will have to learn your interface when I want to use your class.

I much rather you use the conventions of the standard library, which I already know, so I can use your class immediately:

class MyClass {
    protected: 
        std::vector<MySubClass> subclasses;
    public:
        typedef std::vector<MySubClass>::const_iterator const_iterator;

        const_iterator begin() const {return subClasses.begin();}
        const_iterator end  () const {return subClasses.end  ();}

        void insert(const_iterator where, const MySubClass& obj);
        iterator erase(iterator pos);
        iterator erase(iterator begin, iterator end);

        // ...
}