// Boost.Range library

//

//  Copyright Thorsten Ottosen 2003-2004. 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_SUB_RANGE_HPP

#define BOOST_RANGE_SUB_RANGE_HPP

#if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1500)) 

    #pragma warning( push )

    #pragma warning( disable : 4996 )

#endif

#include <boost/detail/workaround.hpp>

#include <boost/range/config.hpp>

#include <boost/range/iterator_range.hpp>

#include <boost/range/value_type.hpp>

#include <boost/range/size_type.hpp>

#include <boost/range/difference_type.hpp>

#include <boost/assert.hpp>

#include <boost/type_traits/is_reference.hpp>

#include <boost/type_traits/remove_reference.hpp>

namespace boost

{

    template< class ForwardRange > 

    class sub_range : public iterator_range< BOOST_DEDUCED_TYPENAME range_iterator<ForwardRange>::type > 

    {

        typedef BOOST_DEDUCED_TYPENAME range_iterator<ForwardRange>::type iterator_t;

        typedef iterator_range< iterator_t  > base;

        typedef BOOST_DEDUCED_TYPENAME base::impl impl;

    public:

        typedef BOOST_DEDUCED_TYPENAME range_value<ForwardRange>::type            value_type;

        typedef BOOST_DEDUCED_TYPENAME range_iterator<ForwardRange>::type         iterator;

        typedef BOOST_DEDUCED_TYPENAME range_iterator<const ForwardRange>::type   const_iterator;

        typedef BOOST_DEDUCED_TYPENAME range_difference<ForwardRange>::type       difference_type;

        typedef BOOST_DEDUCED_TYPENAME range_size<ForwardRange>::type             size_type;

        typedef BOOST_DEDUCED_TYPENAME base::reference                            reference;

    public: // for return value of front/back

        typedef BOOST_DEDUCED_TYPENAME 

                boost::mpl::if_< boost::is_reference<reference>,

                                 const BOOST_DEDUCED_TYPENAME boost::remove_reference<reference>::type&, 

                                 reference >::type const_reference;

    public:

        sub_range() : base() 

        { }

#if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1500) ) 

        sub_range( const sub_range& r ) 

            : base( static_cast<const base&>( r ) )  

        { }  

#endif

        template< class ForwardRange2 >

        sub_range( ForwardRange2& r ) : 

#if BOOST_WORKAROUND(BOOST_INTEL_CXX_VERSION, <= 800 )

            base( impl::adl_begin( r ), impl::adl_end( r ) )

#else

            base( r )

#endif        

        { }

        template< class ForwardRange2 >

        sub_range( const ForwardRange2& r ) : 

#if BOOST_WORKAROUND(BOOST_INTEL_CXX_VERSION, <= 800 )

            base( impl::adl_begin( r ), impl::adl_end( r ) )

#else

            base( r )

#endif                

        { }

        template< class Iter >

        sub_range( Iter first, Iter last ) :

            base( first, last )

        { }

        template< class ForwardRange2 >

        sub_range& operator=( ForwardRange2& r )

        {

            base::operator=( r );

            return *this;

        }

        template< class ForwardRange2 >

        sub_range& operator=( const ForwardRange2& r )

        {

            base::operator=( r );

            return *this;

        }   

        sub_range& operator=( const sub_range& r )

        {

            base::operator=( static_cast<const base&>(r) );

            return *this;            

        }

    public:

        iterator        begin()          { return base::begin(); }

        const_iterator  begin() const    { return base::begin(); }

        iterator        end()            { return base::end();   }

        const_iterator  end() const      { return base::end();   }

        difference_type size() const     { return base::size();  }   

    public: // convenience

        reference front()

        {

            return base::front();

        }

        const_reference front() const

        {

            return base::front();

        }

        reference back()

        {

            return base::back();

        }

        const_reference back() const

        {

            return base::back();

        }

        reference operator[]( difference_type sz )

        {

            return base::operator[](sz);

        }

        const_reference operator[]( difference_type sz ) const

        {

            return base::operator[](sz);

        }

    };

    template< class ForwardRange, class ForwardRange2 >

    inline bool operator==( const sub_range<ForwardRange>& l,

                            const sub_range<ForwardRange2>& r )

    {

        return iterator_range_detail::equal( l, r );

    }

    template< class ForwardRange, class ForwardRange2 >

    inline bool operator!=( const sub_range<ForwardRange>& l,

                            const sub_range<ForwardRange2>& r )

    {

        return !iterator_range_detail::equal( l, r );

    }

    template< class ForwardRange, class ForwardRange2 >

    inline bool operator<( const sub_range<ForwardRange>& l,

                           const sub_range<ForwardRange2>& r )

    {

        return iterator_range_detail::less_than( l, r );

    }

} // namespace 'boost'

#if BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1500)) 

    #pragma warning( pop )

#endif

#endif