// (C) Copyright Thorsten Ottosen 2005

// (C) Copyright Howard Hinnant 2004

// (C) Copyright Jonathan Turkanis 2004

// Distributed under 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.)

//

// Contains type traits machinery for incomplete arrays. MPL compatibility

// is included for completeness, but is not necessary for the current 

// application.

// 

#ifndef BOOST_MOVE_PTR_ARRAYS_HPP_INCLUDED

#define BOOST_MOVE_PTR_ARRAYS_HPP_INCLUDED

#include <boost/config.hpp> // BOOST_STATIC_CONSTANT.

#include <boost/mpl/aux_/lambda_support.hpp>

#include <boost/mpl/and.hpp>

#include <boost/mpl/bool.hpp>

#include <boost/mpl/identity.hpp>

#include <boost/mpl/if.hpp>

#include <boost/type_traits/is_array.hpp>

#include <boost/type_traits/is_convertible.hpp>

#include <boost/type_traits/is_same.hpp>

#include <boost/type_traits/remove_bounds.hpp>

#include <boost/type_traits/remove_cv.hpp>

#include <boost/utility/enable_if.hpp>

namespace boost { namespace ptr_container_detail { namespace move_ptrs {

// From Howard Hinnant.

template<typename T, typename U>

struct is_array_convertible {

    typedef typename remove_bounds<T>::type      t_element; 

    typedef typename remove_bounds<U>::type      u_element; 

    typedef typename remove_cv<t_element>::type  t_base; 

    typedef typename remove_cv<u_element>::type  u_base; 

    typedef typename 

            mpl::and_<

                is_array<T>,

                is_array<U>,

                is_same<t_base, u_base>,

                is_convertible<t_element*, u_element*>

            >::type                                     type;

    BOOST_STATIC_CONSTANT(bool, value = type::value);

    BOOST_MPL_AUX_LAMBDA_SUPPORT(2, is_array_convertible, (T, U))

};

template<typename T, typename U>

struct is_smart_ptr_convertible 

    : mpl::if_<

          is_array<T>,

          is_array_convertible<T, U>,

          is_convertible<T*, U*> 

      >::type

    { };

#ifndef BOOST_NO_SFINAE

    template<typename Src, typename Tgt, typename T = void>

    struct enable_if_convertible 

        : enable_if< 

              is_smart_ptr_convertible<Src, Tgt>,

              T

          >

        { };

#else

    template<typename Src, typename Tgt, class T >

    struct enable_if_convertible : mpl::identity<T> { };

#endif

} } }         // End namespaces ptr_container_detail, move_ptrs, boost.

#endif      // #ifndef BOOST_MOVE_PTR_ARRAYS_HPP_INCLUDED