Question

Is there an easy way of creating a vector of pointers to the elements of a vector?

i.e. easier than the below

std::vector<T*> fn(std::vector<T> &v)
{
  std::vector<T*> r;

  for (int i = 0; i < v.size(); i++)
  {
    r.push_back(&v[i]);
  }

  return r;
}

EDIT: Incoming vector by reference

Answer 1

As @Benoit suggested, it is a bad idea to store these pointers. But if you really want to do it, you can use std::transform like this:

template<class T>
struct Address
{
    T* operator()(T& t) const
    {
        return &t;
    }
};


template<class T>
vector<T*> fn(vector<T>&  v)
{
  vector<T*> r;
  transform(v.begin(), v.end(), back_inserter(r), Address<T>());
  return r;
}


int main( void )
{
    vector<int> a;
    a.push_back(0);
    fn(a);
}