使用boost :: indirect_iterator

Question

当尝试使用 boost :: indirect_iterator 时，我得到“int不是类，结构或联合类型”。 谁能看到我哪里出错？

#include <iostream>
#include <set>

#include <boost/iterator/indirect_iterator.hpp>

// Expose the itererator if the container stores pointers.
class MyCollection
{
public:
  // Iterator interface
  typedef boost::indirect_iterator<int*> iterator;

  iterator begin() { return objects.begin(); }

  iterator end() { return objects.end(); }

private:

  std::set<int*> objects;
};

int main()
{
  MyCollection myCollection;

  for(MyCollection::iterator iterator = myCollection.begin(); iterator != myCollection.end(); iterator++)
  {
    std::cout << " " << *iterator;
  }
  return 0;
}

Answer 1

事实证明你必须使用：

typedef boost::indirect_iterator<std::set<int*>::iterator> iterator;