[Boost-users] iterator_range error

From: abir basak (abirbasak_at_[hidden])
Date: 2007-02-23 02:35:56

I am facing problem related to iterator_range.
It's type is not propagating  properly, when I return such thing from a 
function. (compiler VS 7.1 ,Windows )
The code below shows it.

This is an extension of a vector, which returns range.
typedef std::pair<std::size_t,std::size_t> pair_t;
typedef std::vector<std::size_t> index_t;
template<typename T>
class vector_e : private std::vector<T>{
public:	
        typedef vector_e<T> self_type;
        typedef typename std::vector<T>::iterator iterator;
        typedef typename std::vector<T>::const_iterator const_iterator;
        typedef typename std::vector<T>::pointer pointer;
        typedef typename std::vector<T>::const_pointer const_pointer;
        typedef typename std::vector<T>::reference reference;
        typedef typename std::vector<T>::const_reference const_reference;
        typedef typename std::vector<T>::difference_type difference_type;
        typedef typename std::vector<T>::size_type size_type;
        //typedef sub_range_t<self_type> range;
        //typedef sub_range_t<const self_type> const_range;
        typedef typename std::vector<T>::size_type size_type;	
        typedef typename boost::permutation_iterator<typename iterator,typename 
index_t::const_iterator> index_iterator;
        typedef typename boost::permutation_iterator<typename 
const_iterator,typename index_t::const_iterator> const_index_iterator;
        //typedef sub_range_t<self_type,index_iterator,const_index_iterator> 
index_range;
        //typedef 
sub_range_t<self_type,const_index_iterator,const_index_iterator> 
const_index_range;
        typedef boost::iterator_range<index_iterator> index_range;
        typedef boost::iterator_range<const_index_iterator> const_index_range;

        typedef boost::sub_range<self_type> range;
        typedef boost::sub_range<const self_type> const_range;

        vector_e() : std::vector<T>(){}
        using std::vector<T>::begin;
        using std::vector<T>::end;
        using std::vector<T>::operator [];
        using std::vector<T>::insert;
        const_iterator const_begin()const{
                return begin();
        }
        const_iterator const_end()const{
                return end();
        }
        index_iterator begin_i(const index_t& i){
                return boost::make_permutation_iterator(begin(),i.begin());
        }
        const_index_iterator begin_i(const index_t& i)const{
     return boost::make_permutation_iterator(begin(),i.begin());
        }
        
        index_iterator end_i(const index_t& i){
         return boost::make_permutation_iterator(begin(),i.end());
        }
        const_index_iterator end_i(const index_t& i)const{
                return boost::make_permutation_iterator(begin(),i.end());
        }
        range get_range(const pair_t& r){
                return boost::make_iterator_range(begin()+r.first,begin()+r.second);		
        }
        const_range get_range(const pair_t& r)const{		
                return boost::make_iterator_range(begin()+r.first,begin()+r.second);
        }	
        index_range get_range(const index_t& i){
                index_iterator b = boost::make_permutation_iterator(begin(),i.begin());
                index_iterator e = boost::make_permutation_iterator(begin(),i.end());		
                return boost::make_iterator_range(b,e);
        }
        const_index_range get_range(const index_t& i)const{
                const_index_iterator b = 
boost::make_permutation_iterator(begin(),i.begin());
                const_index_iterator e = 
boost::make_permutation_iterator(begin(),i.end());
                return boost::make_iterator_range(b,e);
        }	
};

Now, to use it like this,
typedef vector_e<trace> trace_buffer;
typedef 
boost::permutation_iterator<trace_buffer::iterator,index_t::iterator> 
index_iterator;
typedef boost::sub_range<trace_buffer> trace_range;
typedef boost::iterator_range<index_iterator> trace_index_range;
trace_buffer traces;

struct character{
        index_t index;
        trace_index_range get_traces(){
                index_iterator b = 
boost::make_permutation_iterator(traces.begin(),index.begin());
                index_iterator e = 
boost::make_permutation_iterator(traces.begin(),index.end());
                //return boost::make_iterator_range(b,e);
                return traces.get_range(index);///This doesn't work, while previous 
commented line works !
        }
};	
Thus to say, I am unable to forward a call to iterator_range from one 
function to another preserving the type.
(Previously the same problem was there with sub_range with 1.33.1 
download. Now that one is solved with a later cvs version ) .

Any help is appreciated ....

thanks'
abir
-- 
Abir Basak, Member IEEE
Software Engineer, Read Ink Technologies
B. Tech, IIT Kharagpur
email: abir_at_[hidden]
homepage: www.abirbasak.com