c++ - Cast vector<T> to vector<const T>

Question

I have a member variable of type vector<T> (where is T is a custom class, but it could be int as well.) I have a function from which I want to return a pointer to this vector, but I don't want the caller to be able to change the vector or it's items. So I want the return type to be const vector<const T>*

None of the casting methods I tried worked. The compiler keeps complaining that T is not compatible with const T.

Here's some code that demonstrates the gist of what I'm trying to do;

vector<int> a;
const vector<const int>* b = (const vector<const int>* ) (&a);

This code doesn't compile for me.

Thanks in advance!

Answer 1

If you have a const vector<int> you cannot modify the container, nor can you modify any of the elements in the container. You don't need a const vector<const int> to achieve those semantics.