1、Iterator——提供一种方法访问一个容器对象中各个元素，而又无需暴露该对象的内部细节
#include <iostream>
#include <vector>
#include <numeric>
using namespace std;
int main ()
{
vector<int> vInt(5);
iota (vInt.begin(),vInt.end(),1);
vector<int>::iterator It = vInt.begin();
while ( It != vInt.end() )
cout << It++ << " ";
cout << ;
// or
for ( It = vInt.begin(); It != vInt.end(); It++ )
cout << It << " ";
cout << ;
return 0;
}
运行结果:
// 1 2 3 4 5
// 1 2 3 4 5
2、istream_iterator——专门针对标准输入流的迭代器
#include <iostream>
#include <algorithm>
#include <vector>
#include <string>
using namespace std;
int main ()
{
//第一种运用方法：定义一个int类型的迭代器
istream_iterator<int> start_cin(cin);
istream_iterator<int> end_of_cin;
vector<int> v;
cout << "Enter sequance of integers "
<< "(d - quit) : ";
copy(start_cin,end_of_cin,back_inserter(v));
for ( vector<int>::iterator It = v.begin();
It != v.end(); It++ )
cout << *It << " - ";
cout << endl;
//第二种方法：定义一种string类型的迭代器
vector<string> vS;
cout << "Enter three strings : ";
for ( int i = 0; i < 3; i++ )
vS.push_back(*istream_iterator<string>(cin));
ostream_iterator<string> sIt(cout,", ");
copy(vS.begin(),vS.end(),sIt);
cout << endl;
return 0;
}
运行结果:
// Enter sequance of integers (d - quit) : 2 3 4
// 2 - 3 - 4 -
// Enter three strings : one two three
// one, two, three,
3、ostream_iterator——专门针对标准输出流的迭代器
#include <iostream>
#include <vector>
#include <algorithm>
#include <fstream>
using namespace std;
int main ()
{
int ary[] = {2,5,7,2,8,9};
//以输出方式打开或新建文件
ofstream ofile("TEST.DAT");
// 写入标准输出
copy(ary,ary+6,ostream_iterator<int>(cout," - "));
// 写入 "TEST.DAT" 文件中
copy(ary,ary+6,ostream_iterator<int>(ofile,"\n"));
ofile.close();
cout << endl;
//以输入方式打开或新建文件
ifstream ifile("TEST.DAT");
istream_iterator<int> start_file(ifile);
istream_iterator<int> end_file;
// 从文件读取内容写入到标准输出
copy(start_file,end_file,
ostream_iterator<int>(cout," * "));
ifile.close();
cout << endl;
return 0;
}
运行结果:
// 2 - 5 - 7 - 2 - 8 - 9 -
// 2 * 5 * 7 * 2 * 8 * 9 *
4、insert_iterator——用于定义一个可自增减并赋值的迭代器对象
#include <iostream>
#include <list>
#include <algorithm>
using namespace std;
int main ()
{
list<int> L;
L.push_front(3);
insert_iterator<list<int> > ii(L, L.begin());
*ii++ = 0;
*ii++ = 1;
*ii++ = 2;
copy(L.begin(), L.end(),
ostream_iterator<int>(cout, " "));
}
运行结果:
// 0 1 2 3.
5、inserter——向指定的容器中迭代插入元素，使用insert实现插入操作，需指定第二参数指向插入起始位置的迭代器
#include <iostream>
#include <set>
#include <algorithm>
using namespace std;
int main()
{
int a[] = {1, 3, 5, 7, 9, 10};
int b[] = {1, 2, 3, 4, 5, 6};
set<int> result;
//merge合并两个有序的sequence，默认为<比较，可自定义比较函数comp，
结果保存在[result, result + (last1 - first1) + (last2 - first2)) 中。
merge(a, a+6, b, b+6,
inserter(result, result.begin()));
copy(result.begin(), result.end(),
ostream_iterator<int>(cout, " "));
cout << endl;
return 0;
}
运行结果:
// 1 2 3 4 5 6 7 9 10
6、front_inserter——向指定的容器中迭代插入元素，使用push_front 实现插入
#include <iostream>
#include <deque>
#include <algorithm>
using namespace std;
int main()
{
deque<int> d;
front_inserter(d) = 100;
front_inserter(d) = 200;
copy(d.begin(),d.end(),
ostream_iterator<int>(cout," "));
cout << endl;
// 用 front_inserter 再次插入所有元素
copy (d.begin(), d.end(),
front_inserter(d));
copy(d.begin(),d.end(),
ostream_iterator<int>(cout," "));
cout << endl;
return 0;
}
运行结果:
// 200 100
// 200 100 200 100
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