Question

I was wondering if there is an iterator in the STL that dereferences the object pointed before returning it. This could be very useful when manipulating containers aggregating pointers. Here’s an example of what I would like to be able to do:

#include <vector> #include <iterator> #include <algorithm>  using namespace std;  int main() {   vector<int*> vec;    int i = 1;   int j = 2;   int k = 3;    vec.push_back(&i);   vec.push_back(&j);   vec.push_back(&k);    copy(deref_iterator(vec.begin()),         deref_iterator(vec.end()),         ostream_iterator<int>(cout, ' ')); // prints '1 2 3'    return 0; } 

Answer 1

Try Boost’s indirect_iterator.

An indirect_iterator has the same category as the iterator it is wrapping. For example, an indirect_iterator<int**> is a random access iterator.