Is it possible the commented below condition. With regular ranges i make as many 'base()' calls as may adaptors i had applied. Obviously it's impossible with any_range. So what should i do ?

#include <map>

#define BOOST_RANGE_ENABLE_CONCEPT_ASSERT 0

#include <boost/range/adaptors.hpp>

#include <boost/range/algorithm.hpp>

#include <boost/range/numeric.hpp>

#include <boost/bind.hpp>

#include <boost/range/any_range.hpp>

struct foo{

int x, y;

};

inline bool is_valid(int x){ return x > 0;}

int main()

{

using namespace boost::adaptors; using boost::bind;

typedef std::map<char, foo> map_t;

typedef const int type;

typedef boost::any_range<

type, boost::forward_traversal_tag,

typename boost::add_reference<type>::type,

std::ptrdiff_t

    > forward_range_t;

map_t m;

forward_range_t rng = m | map_values | transformed(bind(&foo::x, _1)); // note: don't compile without BOOST_RANGE_ENABLE_CONCEPT_ASSERT defined as 0

forward_range_t::const_iterator found = boost::find_if(rng, is_valid);

// found == boost::end(m); how to do it right ?

}