// 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_BEGIN_HPP
#define BOOST_RANGE_BEGIN_HPP

#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif

#include <boost/range/config.hpp>

#ifndef BOOST_NO_RANGE_BASED_FOR
#include <boost/mpl/bool.hpp>
#include <boost/utility/enable_if.hpp>
#include <boost/range/iterator.hpp>

namespace boost
{

using std::begin;

namespace range_detail
{
    template <typename T>
    struct has_begin_impl
    {
        typedef char true_type;
        typedef char false_type[2];

        template <typename S>
        static true_type& check(S* s_ptr, decltype(s_ptr->begin())* = 0);

        template <typename S>
        static false_type& check(...);

        static const bool value = sizeof(check<T>(0)) == sizeof(true_type);
    };

    template <typename T>
    struct has_begin : boost::mpl::bool_<has_begin_impl<T>::value> {};
}

template <typename Range>
inline typename boost::range_iterator<Range>::type
begin(Range& rng, typename disable_if<range_detail::has_begin<Range>>::type* = 0)
{
    return range_begin(rng);
}

template <typename Range>
inline typename boost::range_iterator<Range const>::type
begin(Range const& rng, typename disable_if<range_detail::has_begin<Range>>::type* = 0)
{
    return range_begin(rng);
}

}
#else

#ifdef BOOST_NO_FUNCTION_TEMPLATE_ORDERING
#include <boost/range/detail/begin.hpp>
#else

#include <boost/range/iterator.hpp>

namespace boost
{

#if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564)) && \
    !BOOST_WORKAROUND(__GNUC__, < 3) \
    /**/
namespace range_detail
{
#endif

    //////////////////////////////////////////////////////////////////////
    // primary template
    //////////////////////////////////////////////////////////////////////

    template< typename C >
    inline BOOST_DEDUCED_TYPENAME range_iterator<C>::type
    range_begin( C& c )
    {
        //
        // If you get a compile-error here, it is most likely because
        // you have not implemented range_begin() properly in
        // the namespace of C
        //
        return c.begin();
    }

    //////////////////////////////////////////////////////////////////////
    // pair
    //////////////////////////////////////////////////////////////////////

    template< typename Iterator >
    inline Iterator range_begin( const std::pair<Iterator,Iterator>& p )
    {
        return p.first;
    }

    template< typename Iterator >
    inline Iterator range_begin( std::pair<Iterator,Iterator>& p )
    {
        return p.first;
    }

    //////////////////////////////////////////////////////////////////////
    // array
    //////////////////////////////////////////////////////////////////////

    //
    // May this be discarded? Or is it needed for bad compilers?
    //
    template< typename T, std::size_t sz >
    inline const T* range_begin( const T (&a)[sz] )
    {
        return a;
    }

    template< typename T, std::size_t sz >
    inline T* range_begin( T (&a)[sz] )
    {
        return a;
    }


#if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564)) && \
    !BOOST_WORKAROUND(__GNUC__, < 3) \
    /**/
} // namespace 'range_detail'
#endif


template< class T >
inline BOOST_DEDUCED_TYPENAME range_iterator<T>::type begin( T& r )
{
#if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564)) && \
    !BOOST_WORKAROUND(__GNUC__, < 3) \
    /**/
    using namespace range_detail;
#endif
    return range_begin( r );
}

template< class T >
inline BOOST_DEDUCED_TYPENAME range_iterator<const T>::type begin( const T& r )
{
#if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564)) && \
    !BOOST_WORKAROUND(__GNUC__, < 3) \
    /**/
    using namespace range_detail;
#endif
    return range_begin( r );
}

} // namespace boost

#endif // BOOST_NO_FUNCTION_TEMPLATE_ORDERING

namespace boost
{
    template< class T >
    inline BOOST_DEDUCED_TYPENAME range_iterator<const T>::type
    const_begin( const T& r )
    {
        return boost::begin( r );
    }
}

#endif // BOOST_NO_RANGE_BASED_FOR

#endif