Returning a vector by value or by reference

[roddomi]

Hi,

I am designing a class that has a vector as a private member. My class also has a member function that returns the vector. I am trying to decide if this function should return a copy of the private vector or a reference to it:

#include <vector>

using namespace std;

class A {
    public:
        vector<int> numbers1() {
            return _numbers;
        }

        vector<int>& numbers2() {
            return _numbers;
        }

    private:
        vector<int> _numbers;
};

I would like to allow users to iterate thru the vector using numbers2().begin() and numbers2().end() directly (Note that this wouldn't work using number1 since both expressions return a different copy of the vector). But I've heard that I should avoid returning handles to object internals because of possible dangling handlers. I would like to know the thoughts of this group.

Thank you.