// Copyright David Abrahams 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)

#ifndef IS_INCREMENTABLE_DWA200415_HPP

# define IS_INCREMENTABLE_DWA200415_HPP

# include <boost/type_traits/detail/template_arity_spec.hpp>

# include <boost/type_traits/remove_cv.hpp>

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

# include <boost/mpl/bool.hpp>

# include <boost/detail/workaround.hpp>

// Must be the last include

# include <boost/type_traits/detail/bool_trait_def.hpp>

namespace boost { namespace detail { 

// is_incrementable<T> metafunction

//

// Requires: Given x of type T&, if the expression ++x is well-formed

// it must have complete type; otherwise, it must neither be ambiguous

// nor violate access.

// This namespace ensures that ADL doesn't mess things up.

namespace is_incrementable_

{

  // a type returned from operator++ when no increment is found in the

  // type's own namespace

  struct tag {};

  // any soaks up implicit conversions and makes the following

  // operator++ less-preferred than any other such operator that

  // might be found via ADL.

  struct any { template <class T> any(T const&); };

  // This is a last-resort operator++ for when none other is found

# if BOOST_WORKAROUND(__GNUC__, == 4) && __GNUC_MINOR__ == 0 && __GNUC_PATCHLEVEL__ == 2

}

namespace is_incrementable_2

{

  is_incrementable_::tag operator++(is_incrementable_::any const&);

  is_incrementable_::tag operator++(is_incrementable_::any const&,int);

}

using namespace is_incrementable_2;

namespace is_incrementable_

{

# else

  tag operator++(any const&);

  tag operator++(any const&,int);

# endif 

# if BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3202)) \

    || BOOST_WORKAROUND(BOOST_MSVC, <= 1300)

#  define BOOST_comma(a,b) (a)

# else 

  // In case an operator++ is found that returns void, we'll use ++x,0

  tag operator,(tag,int);  

#  define BOOST_comma(a,b) (a,b)

# endif 

  // two check overloads help us identify which operator++ was picked

  char (& check(tag) )[2];

  template <class T>

  char check(T const&);

  template <class T>

  struct impl

  {

      static typename boost::remove_cv<T>::type& x;

      BOOST_STATIC_CONSTANT(

          bool

        , value = sizeof(is_incrementable_::check(BOOST_comma(++x,0))) == 1

      );

  };

  template <class T>

  struct postfix_impl

  {

      static typename boost::remove_cv<T>::type& x;

      BOOST_STATIC_CONSTANT(

          bool

        , value = sizeof(is_incrementable_::check(BOOST_comma(x++,0))) == 1

      );

  };

}

# undef BOOST_comma

template<typename T> 

struct is_incrementable 

BOOST_TT_AUX_BOOL_C_BASE(::boost::detail::is_incrementable_::impl<T>::value)

{ 

    BOOST_TT_AUX_BOOL_TRAIT_VALUE_DECL(::boost::detail::is_incrementable_::impl<T>::value)

    BOOST_MPL_AUX_LAMBDA_SUPPORT(1,is_incrementable,(T))

};

template<typename T> 

struct is_postfix_incrementable 

BOOST_TT_AUX_BOOL_C_BASE(::boost::detail::is_incrementable_::impl<T>::value)

{ 

    BOOST_TT_AUX_BOOL_TRAIT_VALUE_DECL(::boost::detail::is_incrementable_::postfix_impl<T>::value)

    BOOST_MPL_AUX_LAMBDA_SUPPORT(1,is_postfix_incrementable,(T))

};

} // namespace detail

BOOST_TT_AUX_TEMPLATE_ARITY_SPEC(1, ::boost::detail::is_incrementable)

BOOST_TT_AUX_TEMPLATE_ARITY_SPEC(1, ::boost::detail::is_postfix_incrementable)

} // namespace boost

# include <boost/type_traits/detail/bool_trait_undef.hpp>

#endif // IS_INCREMENTABLE_DWA200415_HPP