variant pixel buffer to vector using boost::apply_visitor - c++

Question

I am trying to convert variablepixelbuffer.vbuffer() to a vector of double values using apply_visitor in boost.
I came with this piece of code till now :
struct GetVector : public boost::static_visitor<std::vector<double>>
{
//values will be returned in a pair. double is
// used since it can contain the value for any pixel type
typedef std::vector<double> result_type;
template<typename T
void myfunction (const T& i) { // function:
result_type.push_back(static_cast<double>(*i));
}
template<typename T>
result_type
operator() (const T& v)
{
typedef typename T::element_type::value_type value_type;
std::for_each (v->data(), v->data() + v->num_elements(), myfunction);
return result_type;
}
};
/* pixel-example-start */
void
readPixelData(const FormatReader& reader,
std::ostream& stream,int x,int y,int w,int h)
{
// Change the current series to this index
reader.setSeries(0);
// Get total number of planes (for this image index)
dimension_size_type pc = reader.getImageCount();
// Pixel buffer
VariantPixelBuffer buf;
dimension_size_type xd = x;
dimension_size_type yd = y;
dimension_size_type wd = w;
dimension_size_type hd = h;
// Loop over planes (for this image index)
for (dimension_size_type p = 0 ; p < pc; p++)
{
// Read the entire plane into the pixel buffer.
reader.openBytes(p, buf,xd,yd,wd,hd);
}
GetVector visitor;
GetVector::result_type result = boost::apply_visitor(visitor, buf.vbuffer());
}
But i am getting some long errors, and some piece of it are
/usr/include/boost/variant/detail/apply_visitor_unary.hpp:60:43:
required from ‘typename Visitor::result_type
boost::apply_visitor(Visitor&, Visitable&) [with Visitor =
MinMaxVisitor; Visitable =
boost::variant >,
boost::mpl::v_item >,
boost::mpl::v_item
, boost::mpl::v_item >,
boost::mpl::v_item >,
boost::mpl::v_item >,
boost::mpl::v_item
, boost::mpl::v_item
, boost::mpl::v_item
, boost::mpl::v_item
, boost::mpl::v_item
, boost::mpl::vector0, 1>, 1>, 1>, 1>, 1>, 1>, 1>, 1>, 1>, 1>, 1> >, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_,
boost::detail::variant::void_, boost::detail::variant::void_>;
typename Visitor::result_type = std::vector >]’ read_subimage.C:82:85: required from here
/usr/include/c++/4.8/bits/stl_algo.h:4417:14: error: must use ‘.’ or
‘->’ to call pointer-to-member function in ‘__f (...)’, e.g. ‘(...
->* __f) (...)’
How can i reslove this, I need to get the pixel buffer data into vector .