C++Iterator Categories(迭代器种类)

迭代器支持操作：
Input iterators : ==, !=, ++, *, ->                    eg:istream_iterator
Output iterators : ++, *                                  eg:ostream_iterator
Forward iterators : ==, !=, ++, *, ->               eg:forward_list
Bidirectional iterators : ==, !=, ++, --, *, ->    Aside from forward_list,the library container supply iterators. eg:vector
Random-access iterators : ==, !=, <, <=, >, >=, ++, --, +, +=, -, -=, -(two iterators), *, ->, iter[n] == * (iter + n)   provide constant-time access to any position in the sequence. eg:vector

上面截图来自：http://en.cppreference.com/w/cpp/iterator