mloskot@xenial:~/tmp$ cat gil_ticket_8896.cpp
#include <iostream>
#include <boost/gil/gil_all.hpp>
using namespace boost;
namespace bg = boost::gil;
int main(int argc, char **argv)
{
    bg::gray8_image_t img(2,2);
    bg::gray8_view_t vw(bg::view(img));
    bg::gray8_view_t::point_t p(0,0);
    bg::gray8_view_t::axis<0>::iterator iter = vw.template axis_iterator<0>(p);

    std::cout << (*iter)[0] << std::endl;
    return 0;
}

mloskot@xenial:~/tmp$ g++ -std=c++11 -I/mnt/d/boost.wsl  gil_ticket_8896.cpp
In file included from /mnt/d/boost.wsl/boost/gil/algorithm.hpp:32:0,
                 from /mnt/d/boost.wsl/boost/gil/gil_all.hpp:27,
                 from gil_ticket_8896.cpp:2:
/mnt/d/boost.wsl/boost/gil/image_view.hpp: In instantiation of ‘typename boost::gil::image_view<L>::axis<D>::iterator boost::gil::image_view<L>::axis_iterator(const point_t&) const [with long unsigned int D = 0; Loc = boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::pixel<unsigned char, boost::gil::layout<boost::mpl::vector1<boost::gil::gray_color_t> > >*> >; typename boost::gil::image_view<L>::axis<D>::iterator = boost::gil::pixel<unsigned char, boost::gil::layout<boost::mpl::vector1<boost::gil::gray_color_t> > >*; boost::gil::image_view<L>::point_t = boost::gil::point2<long int>]’:
gil_ticket_8896.cpp:10:69:   required from here
/mnt/d/boost.wsl/boost/gil/image_view.hpp:139:125: error: invalid operands of types ‘<unresolved overloaded function type>’ and ‘long unsigned int’ to binary ‘operator<’
     template <std::size_t D> typename axis<D>::iterator axis_iterator(const point_t& p) const { return _pixels.axis_iterator<D>(p); }
                                                                                                        ~~~~~~~~~~~~~~~~~~~~~^~

mloskot@xenial:~/tmp$ clang++ -std=c++11 -I/mnt/d/boost.wsl  gil_ticket_8896.cpp
In file included from gil_ticket_8896.cpp:2:
In file included from /mnt/d/boost.wsl/boost/gil/gil_all.hpp:27:
In file included from /mnt/d/boost.wsl/boost/gil/algorithm.hpp:32:
/mnt/d/boost.wsl/boost/gil/image_view.hpp:139:112: error: missing 'template' keyword prior to dependent template name 'axis_iterator'
    template <std::size_t D> typename axis<D>::iterator axis_iterator(const point_t& p) const { return _pixels.axis_iterator<D>(p); }
                                                                                                               ^
gil_ticket_8896.cpp:10:51: note: in instantiation of function template specialization 'boost::gil::image_view<boost::gil::memory_based_2d_locator<boost::gil::memory_based_step_iterator<boost::gil::pixel<unsigned char,
      boost::gil::layout<boost::mpl::vector1<boost::gil::gray_color_t>, boost::mpl::range_c<int, 0, 1> > > *> > >::axis_iterator<0>' requested here
    bg::gray8_view_t::axis<0>::iterator iter = vw.axis_iterator<0>(p);
                                                  ^
1 error generated.