STL之insert_iterator

insert_iterator功能：指定要插入容器的位置,然后向插入点后插入元素。如ListA{1,2,3,4,5,6,7,8,9} 。插入点位置在5处。要插入的链表为ListB{555,666,777}
，则结果为{1,2,3,4,5,555,666,777,6,7,8,9}。
  

     见以下例子

//advance(i, n) 指定迭代器i前进n步 相当于i=i+n//http://www.cplusplus.com/reference/iterator/advance/#include <iostream>#include <iterator>#include <list>using namespace std;void TestAdvance(){  list<int> mylist;  for (int i=0; i<10; i++) mylist.push_back (i*10);  list<int>::iterator it = mylist.begin();  advance (it,5);  cout << "The sixth element in mylist is: " << *it << endl;}//http://www.cplusplus.com/reference/iterator/inserter///输出A链表到B链表中 输出的位置由B链表迭代器的位置指定//this function generates an insert iterator for a container.//template<class InputIterator, class OutputIterator> // OutputIterator copy ( InputIterator first, InputIterator last, OutputIterator result )//{//  while (first!=last) *result++ = *first++;//  return result;//}void TestCopyOutputIterator(){  list<int> firstlist, secondlist;  for (int i=1; i<=5; i++)  { firstlist.push_back(i); secondlist.push_back(i*10); }  list<int>::iterator it;  it = firstlist.begin(); advance (it,3);  copy (secondlist.begin(),secondlist.end(),inserter(firstlist,it));  for ( it = firstlist.begin(); it!= firstlist.end(); ++it )  cout << *it << " ";  cout << endl;}/*template <class Container>  class insert_iterator :    public iterator<output_iterator_tag,void,void,void,void>{protected:  Container* container;  typename Container::iterator iter;public:  typedef Container container_type;  explicit insert_iterator (Container& x, typename Container::iterator i)    : container(&x), iter(i) {}  insert_iterator<Container>& operator= (typename Container::const_reference value)    { iter=container->insert(iter,value); ++iter; return *this; }  insert_iterator<Container>& operator* ()    { return *this; }  insert_iterator<Container>& operator++ ()    { return *this; }  insert_iterator<Container> operator++ (int)    { return *this; }};*///还可以直接使用insert_iterator迭代器void TestCopy(){  list<int> firstlist, secondlist;  for (int i=1; i<=5; i++)  { firstlist.push_back(i); secondlist.push_back(i*10); }  list<int>::iterator it;  it = firstlist.begin(); advance (it,3);  insert_iterator< list<int> > insert_it (firstlist,it);  copy (secondlist.begin(),secondlist.end(),insert_it);  for ( it = firstlist.begin(); it!= firstlist.end(); ++it )  cout << *it << " ";  cout << endl;}int main () {TestAdvance();TestCopyOutputIterator();TestCopy();  return 0;}

结果

The sixth element in mylist is: 501 2 3 10 20 30 40 50 4 51 2 3 10 20 30 40 50 4 5