// Boost.Range library
//
//  Copyright Thorsten Ottosen, Neil Groves 2006 - 2008. Use, modification and
//  distribution is subject to the Boost Software License, Version
//  1.0. (See accompanying file LICENSE_1_0.txt or copy at
//  http://www.boost.org/LICENSE_1_0.txt)
//
// For more information, see http://www.boost.org/libs/range/
//

#ifndef BOOST_RANGE_ADAPTOR_TRANSFORMED_HPP
#define BOOST_RANGE_ADAPTOR_TRANSFORMED_HPP

#include <boost/range/adaptor/argument_fwd.hpp>
#include <boost/range/iterator_range.hpp>
#include <boost/iterator/transform_iterator.hpp>

namespace boost
{
    namespace range_detail
    {

        template< class F, class R >
        struct transform_range : 
            public boost::iterator_range< 
                      boost::transform_iterator< F,
                          BOOST_DEDUCED_TYPENAME range_iterator<R>::type 
                                              >
                                         >
        {
        private:
            typedef boost::iterator_range< 
                      boost::transform_iterator< F,
                        BOOST_DEDUCED_TYPENAME range_iterator<R>::type 
                                              >
                                         >
                base;

        public:
            typedef F transform_fn_type;
            typedef R source_range_type;
            
            transform_range( F f, R& r )
                : base( make_transform_iterator( boost::begin(r), f ),
                        make_transform_iterator( boost::end(r), f ) ) 
            
            { }
        };

        template< class T >
        struct transform_holder : holder<T>
        {
            transform_holder( T r ) : holder<T>(r)
            { }
        };
        
        template< class InputRng, class UnaryFunction >
        inline transform_range<UnaryFunction,InputRng> 
        operator|( InputRng& r, 
                   const transform_holder<UnaryFunction>& f )
        {
            return transform_range<UnaryFunction,InputRng>( f.val, r );   
        }
    
        template< class InputRng, class UnaryFunction >
        inline transform_range<UnaryFunction, const InputRng> 
        operator|( const InputRng& r, 
                   const transform_holder<UnaryFunction>& f )
        {
           return transform_range<UnaryFunction, const InputRng>( f.val, r );   
        }
        
    } // 'range_detail'

    using range_detail::transform_range;
        
    namespace adaptors
    { 
        namespace
        {
            const range_detail::forwarder<range_detail::transform_holder> 
                    transformed = 
                      range_detail::forwarder<range_detail::transform_holder>();
        }
        
        template<class UnaryFunction, class InputRange>
        inline transform_range<UnaryFunction, InputRange>
        transform(InputRange& rng, UnaryFunction fn)
        {
            return transform_range<UnaryFunction, InputRange>(fn, rng);
        }
        
        template<class UnaryFunction, class InputRange>
        inline transform_range<UnaryFunction, const InputRange>
        transform(const InputRange& rng, UnaryFunction fn)
        {
            return transform_range<UnaryFunction, const InputRange>(fn, rng);
        }
    } // 'adaptors'
    
}

#endif