gistfile1.cpp

// 環境
// gcc version 4.5.1 (Gentoo 4.5.1 p1.1, pie-0.4.5)
// boost 1.44.0


#include <boost/iterator/iterator_facade.hpp>
#include <boost/utility.hpp>
#include <boost/range/sub_range.hpp>


template <class Range>
struct slide_range_iterator
    : public boost::iterator_facade<
        slide_range_iterator<Range>,
        boost::sub_range<Range> const,
        boost::forward_traversal_tag
    >
{
    slide_range_iterator()
        : cur_rng_(), end_it_()
    {}

    slide_range_iterator(Range rng, int length)
        : cur_rng_(boost::begin(rng), boost::next(boost::begin(rng), length)),
          end_it_(boost::end(rng))
    {}

private:
    friend class boost::iterator_core_access;

    typedef typename boost::range_iterator<Range>::type inner_iterator;

    boost::sub_range<Range> const& dereference() const {
        return cur_rng_;
    }
    bool equal(slide_range_iterator const& other) const {
        return this->cur_rng_ == other.cur_rng_;
    }
    void increment() {
        if (cur_rng_.end() == end_it_) {
            cur_rng_ = boost::sub_range<Range>();
            end_it_ = inner_iterator();
        }
        else {
            cur_rng_.advance_begin(1);
            cur_rng_.advance_end(1);
        }
    }

private:
    boost::sub_range<Range> cur_rng_;
    inner_iterator end_it_;
};


#include <iostream>
#include <vector>
#include <string>
#include <boost/range/algorithm/equal.hpp>
#include <boost/assign.hpp>
#include <boost/foreach.hpp>


using namespace std;
using namespace boost::assign;


int main(int argc, char *argv[]) {
    vector<int> const rng = {9, 8, 7, 6, 5, 4, 3, 2, 1, 0};
    //string const rng = "abcdefghij";
    auto answer = rng;

    typedef slide_range_iterator<decltype(rng)> sri;

    sri it(rng, 10);
    // なぜか false になる。
    cout << std::boolalpha << boost::equal(*it, answer) << endl;

   // なぜか 0076543210 と表示される。（正解は 9876543210）
   // vector<short> だと 0000543210 になります。
   for (; it != sri(); ++it) {
        BOOST_FOREACH (auto x, *it) {
            cout << x;
        }
        cout << endl;
    }

    return 0;
}