Re: remove_if with a mask

[..]
I threw together something similar to what you have and it *doesn't*
appear to be working.

    16:15:35 Paul Bibbings@JIJOU
    /cygdrive/d/CPPProjects/CLCPP $cat vector_mask.cpp
    // file: vector_mask.cpp

    #include<vector>
    #include<algorithm>
    #include<iostream>

    template<typename T>
    class MaskFunctor {
    public:
       explicit MaskFunctor(std::vector<bool>& mask)
          : mask_(mask)
          , mask_iter_(mask_.begin())
       { }
       bool operator()(const T&)
       {
          if (mask_iter_ == mask_.end())
            return false;
          else
            return *mask_iter_++;
       }
    private:
       std::vector<bool>& mask_;
       std::vector<bool>::const_iterator mask_iter_;
    };

    int main()
    {
       std::vector<bool> mask;
       for (int i = 0; i< 4; ++i)
       {
          mask.push_back(true);
          mask.push_back(false);
       }

       std::vector<int> i_vec;
       for (int i = 0; i< 8; ++i)
            i_vec.push_back(i);

       std::vector<int>::iterator end =
          std::remove_if(i_vec.begin(), i_vec.end(), MaskFunctor<int>(mask));

       i_vec.erase(end, i_vec.end());

       for (std::vector<int>::const_iterator ci = i_vec.begin();
              ci != i_vec.end();
              ++ci)
       {
          std::cout<< *ci<< ' ';
       }
       std::cout<< '\n';
    }

    16:15:41 Paul Bibbings@JIJOU
    /cygdrive/d/CPPProjects/CLCPP $./vector_mask
    2 4 6