ex9_31_2.cpp

//
//  ex9_31.cpp
//  Exercise 9.31 
//
//  Created by pezy on 12/3/14.
//
//  @Brief  The program on page 354 to remove even-valued elements and 
//          duplicate odd ones will not work on a list or forward_list. Why? 
//          Revise the program so that it works on these types as well. 
//  
//  Refactored by Yue Wang Oct 2015  
//

#include <iostream>
#include <forward_list>

using std::forward_list;
using std::cout;
using std::advance;

auto remove_evens_and_double_odds(forward_list<int>& data)
{
    for(auto cur = data.begin(), prv = data.before_begin(); cur != data.end();)
        if (*cur & 0x1)
            cur = data.insert_after(prv, *cur),
            advance(cur, 2),
            advance(prv, 2);
        else
            cur = data.erase_after(prv);
}

int main()
{
    forward_list<int> data { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 };
    remove_evens_and_double_odds(data);
    for (auto i : data)
        cout << i << " ";

    return 0;
}