在STL中是否有dereference_iterator？ [英] Is there a dereference_iterator in the STL?

问题描述

我想知道如果在STL中有一个迭代器，在返回之前取消引用指向的对象。当操作容器聚合指针时，这可能非常有用。这里是我想要做的一个例子：

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;
}

推荐答案

尝试Boost的 indirect_iterator 。

Try Boost's indirect_iterator.

indirect_iterator 与包装的迭代器具有相同的类别。例如， indirect_iterator< int **> 是一个随机访问迭代器。

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

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