///////////////////////////////////////////////////////////////////////////////

// foreach.hpp header file

//

// Copyright 2004 Eric Niebler.

// 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)

//

// Credits:

//  Anson Tsao        - for the initial inspiration and several good suggestions.

//  Thorsten Ottosen  - for Boost.Range, and for suggesting a way to detect

//                      const-qualified rvalues at compile time on VC7.1+

//  Russell Hind      - For help porting to Borland

//  Alisdair Meredith - For help porting to Borland

//  Stefan Slapeta    - For help porting to Intel

#ifndef BOOST_FOREACH

// MS compatible compilers support #pragma once

#if defined(_MSC_VER) && (_MSC_VER >= 1020)

# pragma once

#endif

#include <cstddef>

#include <utility>  // for std::pair

#include <boost/config.hpp>

#include <boost/detail/workaround.hpp>

// Some compilers let us detect even const-qualified rvalues at compile-time

#if BOOST_WORKAROUND(BOOST_MSVC, >= 1310)                                                       \

 || (BOOST_WORKAROUND(__GNUC__, >= 4) && !defined(BOOST_INTEL))                                 \

 || (BOOST_WORKAROUND(__GNUC__, == 3) && (__GNUC_MINOR__ >= 4) && !defined(BOOST_INTEL))

# define BOOST_FOREACH_COMPILE_TIME_CONST_RVALUE_DETECTION

#else

// Some compilers allow temporaries to be bound to non-const references.

// These compilers make it impossible to for BOOST_FOREACH to detect

// temporaries and avoid reevaluation of the collection expression.

# if BOOST_WORKAROUND(BOOST_MSVC, <= 1300)                                                      \

  || BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))                                     \

  || (BOOST_WORKAROUND(BOOST_INTEL_CXX_VERSION, <= 700) && defined(_MSC_VER))                   \

  || BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x570))                                      \

  || BOOST_WORKAROUND(__DECCXX_VER, BOOST_TESTED_AT(60590042))

#  define BOOST_FOREACH_NO_RVALUE_DETECTION

# endif

// Some compilers do not correctly implement the lvalue/rvalue conversion

// rules of the ternary conditional operator.

# if defined(BOOST_FOREACH_NO_RVALUE_DETECTION)                                                 \

  || defined(BOOST_NO_SFINAE)                                                                   \

  || BOOST_WORKAROUND(BOOST_MSVC, BOOST_TESTED_AT(1400))                                        \

  || BOOST_WORKAROUND(BOOST_INTEL_WIN, <= 810)                                                  \

  || BOOST_WORKAROUND(__GNUC__, < 3)                                                            \

  || (BOOST_WORKAROUND(__GNUC__, == 3) && (__GNUC_MINOR__ <= 2))                                \

  || (BOOST_WORKAROUND(__GNUC__, == 3) && (__GNUC_MINOR__ <= 3) && defined(__APPLE_CC__))       \

  || BOOST_WORKAROUND(__IBMCPP__, BOOST_TESTED_AT(600))                                         \

  || BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3206))

#  define BOOST_FOREACH_NO_CONST_RVALUE_DETECTION

# else

#  define BOOST_FOREACH_RUN_TIME_CONST_RVALUE_DETECTION

# endif

#endif

#include <boost/mpl/if.hpp>

#include <boost/mpl/logical.hpp>

#include <boost/mpl/eval_if.hpp>

#include <boost/noncopyable.hpp>

#include <boost/range/end.hpp>

#include <boost/range/begin.hpp>

#include <boost/range/result_iterator.hpp>

#include <boost/type_traits/is_array.hpp>

#include <boost/type_traits/is_const.hpp>

#include <boost/type_traits/is_abstract.hpp>

#include <boost/type_traits/is_base_and_derived.hpp>

#include <boost/iterator/iterator_traits.hpp>

#include <boost/utility/addressof.hpp>

#ifdef BOOST_FOREACH_RUN_TIME_CONST_RVALUE_DETECTION

# include <new>

# include <boost/aligned_storage.hpp>

# include <boost/utility/enable_if.hpp>

# include <boost/type_traits/remove_const.hpp>

#endif

// This must be at global scope, hence the uglified name

enum boost_foreach_argument_dependent_lookup_hack

{

    boost_foreach_argument_dependent_lookup_hack_value

};

namespace boost

{

// forward declarations for iterator_range

template<typename T>

class iterator_range;

// forward declarations for sub_range

template<typename T>

class sub_range;

namespace foreach

{

    ///////////////////////////////////////////////////////////////////////////////

    // in_range

    //

    template<typename T>

    inline std::pair<T, T> in_range(T begin, T end)

    {

        return std::make_pair(begin, end);

    }

    ///////////////////////////////////////////////////////////////////////////////

    // boost::foreach::tag

    //

    typedef boost_foreach_argument_dependent_lookup_hack tag;

    ///////////////////////////////////////////////////////////////////////////////

    // boost::foreach::is_lightweight_proxy

    //   Specialize this for user-defined collection types if they are inexpensive to copy.

    //   This tells BOOST_FOREACH it can avoid the rvalue/lvalue detection stuff.

    template<typename T>

    struct is_lightweight_proxy

      : boost::mpl::false_

    {

    };

    ///////////////////////////////////////////////////////////////////////////////

    // boost::foreach::is_noncopyable

    //   Specialize this for user-defined collection types if they cannot be copied.

    //   This also tells BOOST_FOREACH to avoid the rvalue/lvalue detection stuff.

    template<typename T>

    struct is_noncopyable

    #if !defined(BOOST_BROKEN_IS_BASE_AND_DERIVED) && !defined(BOOST_NO_IS_ABSTRACT)

      : boost::mpl::or_<

            boost::is_abstract<T>

          , boost::is_base_and_derived<boost::noncopyable, T>

        >

    #elif !defined(BOOST_BROKEN_IS_BASE_AND_DERIVED)

      : boost::is_base_and_derived<boost::noncopyable, T>

    #elif !defined(BOOST_NO_IS_ABSTRACT)

      : boost::is_abstract<T>

    #else

      : boost::mpl::false_

    #endif

    {

    };

} // namespace foreach

} // namespace boost

// vc6/7 needs help ordering the following overloads

#ifdef BOOST_NO_FUNCTION_TEMPLATE_ORDERING

# define BOOST_FOREACH_TAG_DEFAULT ...

#else

# define BOOST_FOREACH_TAG_DEFAULT boost::foreach::tag

#endif

///////////////////////////////////////////////////////////////////////////////

// boost_foreach_is_lightweight_proxy

//   Another customization point for the is_lightweight_proxy optimization,

//   this one works on legacy compilers. Overload boost_foreach_is_lightweight_proxy

//   at the global namespace for your type.

template<typename T>

inline boost::foreach::is_lightweight_proxy<T> *

boost_foreach_is_lightweight_proxy(T *&, BOOST_FOREACH_TAG_DEFAULT) { return 0; }

template<typename T>

inline boost::mpl::true_ *

boost_foreach_is_lightweight_proxy(std::pair<T, T> *&, boost::foreach::tag) { return 0; }

template<typename T>

inline boost::mpl::true_ *

boost_foreach_is_lightweight_proxy(boost::iterator_range<T> *&, boost::foreach::tag) { return 0; }

template<typename T>

inline boost::mpl::true_ *

boost_foreach_is_lightweight_proxy(boost::sub_range<T> *&, boost::foreach::tag) { return 0; }

template<typename T>

inline boost::mpl::true_ *

boost_foreach_is_lightweight_proxy(T **&, boost::foreach::tag) { return 0; }

///////////////////////////////////////////////////////////////////////////////

// boost_foreach_is_noncopyable

//   Another customization point for the is_noncopyable trait,

//   this one works on legacy compilers. Overload boost_foreach_is_noncopyable

//   at the global namespace for your type.

template<typename T>

inline boost::foreach::is_noncopyable<T> *

boost_foreach_is_noncopyable(T *&, BOOST_FOREACH_TAG_DEFAULT) { return 0; }

namespace boost

{

namespace foreach_detail_

{

///////////////////////////////////////////////////////////////////////////////

// Define some utilities for assessing the properties of expressions

//

typedef char yes_type;

typedef char (&no_type)[2];

yes_type is_true(boost::mpl::true_ *);

no_type is_true(boost::mpl::false_ *);

// Extracts the desired property from the expression without evaluating it

#define BOOST_FOREACH_PROTECT(expr)                                                             \

    (static_cast<boost::mpl::bool_<1 == sizeof(boost::foreach_detail_::is_true(expr))> *>(0))

template<typename Bool1, typename Bool2>

inline boost::mpl::and_<Bool1, Bool2> *and_(Bool1 *, Bool2 *) { return 0; }

template<typename Bool1, typename Bool2, typename Bool3>

inline boost::mpl::and_<Bool1, Bool2, Bool3> *and_(Bool1 *, Bool2 *, Bool3 *) { return 0; }

template<typename Bool1, typename Bool2>

inline boost::mpl::or_<Bool1, Bool2> *or_(Bool1 *, Bool2 *) { return 0; }

template<typename Bool1, typename Bool2, typename Bool3>

inline boost::mpl::or_<Bool1, Bool2, Bool3> *or_(Bool1 *, Bool2 *, Bool3 *) { return 0; }

template<typename Bool>

inline boost::mpl::not_<Bool> *not_(Bool *) { return 0; }

template<typename T>

inline boost::mpl::false_ *is_rvalue_(T &, int) { return 0; }

template<typename T>

inline boost::mpl::true_ *is_rvalue_(T const &, ...) { return 0; }

template<typename T>

inline boost::is_array<T> *is_array_(T const &) { return 0; }

template<typename T>

inline boost::is_const<T> *is_const_(T &) { return 0; }

#ifndef BOOST_FOREACH_NO_RVALUE_DETECTION

template<typename T>

inline boost::mpl::true_ *is_const_(T const &) { return 0; }

#endif

///////////////////////////////////////////////////////////////////////////////

// auto_any_t/auto_any

//  General utility for putting an object of any type into automatic storage

struct auto_any_base

{

    // auto_any_base must evaluate to false in boolean context so that

    // they can be declared in if() statements.

    operator bool() const

    {

        return false;

    }

};

template<typename T>

struct auto_any : auto_any_base

{

    auto_any(T const &t)

      : item(t)

    {

    }

    // temporaries of type auto_any will be bound to const auto_any_base

    // references, but we still want to be able to mutate the stored

    // data, so declare it as mutable.

    mutable T item;

};

typedef auto_any_base const &auto_any_t;

template<typename T, typename C>

inline BOOST_DEDUCED_TYPENAME boost::mpl::if_<C, T const, T>::type &auto_any_cast(auto_any_t a)

{

    return static_cast<auto_any<T> const &>(a).item;

}

typedef boost::mpl::true_ const_;

///////////////////////////////////////////////////////////////////////////////

// type2type

//

template<typename T, typename C = boost::mpl::false_>

struct type2type

  : boost::mpl::if_<C, T const, T>

{

};

template<typename T, typename C = boost::mpl::false_>

struct foreach_iterator

{

    typedef BOOST_DEDUCED_TYPENAME boost::mpl::eval_if<

        C

      , range_const_iterator<T>

      , range_iterator<T>

    >::type type;

};

template<typename T, typename C = boost::mpl::false_>

struct foreach_reference

  : iterator_reference<BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type>

{

};

///////////////////////////////////////////////////////////////////////////////

// encode_type

//

template<typename T>

inline type2type<T> *encode_type(T &, boost::mpl::false_ *) { return 0; }

template<typename T>

inline type2type<T, const_> *encode_type(T const &, boost::mpl::true_ *) { return 0; }

///////////////////////////////////////////////////////////////////////////////

// set_false

//

inline bool set_false(bool &b) { return b = false; }

///////////////////////////////////////////////////////////////////////////////

// to_ptr

//

template<typename T>

inline T *&to_ptr(T const &)

{

    static T *t = 0;

    return t;

}

// Borland needs a little extra help with arrays

#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))

template<typename T,std::size_t N>

inline T (*&to_ptr(T (&)[N]))[N]

{

    static T (*t)[N] = 0;

    return t;

}

#endif

///////////////////////////////////////////////////////////////////////////////

// derefof

//

template<typename T>

inline T &derefof(T *t)

{

    // This is a work-around for a compiler bug in Borland. If T* is a pointer to array type U(*)[N],

    // then dereferencing it results in a U* instead of U(&)[N]. The cast forces the issue.

    return reinterpret_cast<T &>(

        *const_cast<char *>(

            reinterpret_cast<char const volatile *>(t)

        )

    );

}

#ifdef BOOST_FOREACH_COMPILE_TIME_CONST_RVALUE_DETECTION

///////////////////////////////////////////////////////////////////////////////

// Detect at compile-time whether an expression yields an rvalue or

// an lvalue. This is rather non-standard, but some popular compilers

// accept it.

///////////////////////////////////////////////////////////////////////////////

///////////////////////////////////////////////////////////////////////////////

// rvalue_probe

//

template<typename T>

struct rvalue_probe

{

    struct private_type_ {};

    // can't ever return an array by value

    typedef BOOST_DEDUCED_TYPENAME boost::mpl::if_<

        boost::mpl::or_<boost::is_abstract<T>, boost::is_array<T> >, private_type_, T

    >::type value_type;

    operator value_type();

    operator T &() const;

};

template<typename T>

rvalue_probe<T> const make_probe(T const &t);

# define BOOST_FOREACH_IS_RVALUE(COL)                                                           \

    boost::foreach_detail_::and_(                                                               \

        boost::foreach_detail_::not_(boost::foreach_detail_::is_array_(COL))                    \

      , BOOST_FOREACH_PROTECT(boost::foreach_detail_::is_rvalue_(                               \

            (true ? boost::foreach_detail_::make_probe(COL) : (COL)), 0)))

#elif defined(BOOST_FOREACH_RUN_TIME_CONST_RVALUE_DETECTION)

///////////////////////////////////////////////////////////////////////////////

// Detect at run-time whether an expression yields an rvalue

// or an lvalue. This is 100% standard C++, but not all compilers

// accept it. Also, it causes FOREACH to break when used with non-

// copyable collection types.

///////////////////////////////////////////////////////////////////////////////

///////////////////////////////////////////////////////////////////////////////

// rvalue_probe

//

template<typename T>

struct rvalue_probe

{

    rvalue_probe(T &t, bool &b)

      : value(t)

      , is_rvalue(b)

    {

    }

    struct private_type_ {};

    // can't ever return an array or an abstract type by value

    #ifdef BOOST_NO_IS_ABSTRACT

    typedef BOOST_DEDUCED_TYPENAME boost::mpl::if_<

        boost::is_array<T>, private_type_, T

    >::type value_type;

    #else

    typedef BOOST_DEDUCED_TYPENAME boost::mpl::if_<

        boost::mpl::or_<boost::is_abstract<T>, boost::is_array<T> >, private_type_, T

    >::type value_type;

    #endif

    operator value_type()

    {

        this->is_rvalue = true;

        return this->value;

    }

    operator T &() const

    {

        return this->value;

    }

private:

    T &value;

    bool &is_rvalue;

};

template<typename T>

rvalue_probe<T> make_probe(T &t, bool &b) { return rvalue_probe<T>(t, b); }

template<typename T>

rvalue_probe<T const> make_probe(T const &t, bool &b)  { return rvalue_probe<T const>(t, b); }

///////////////////////////////////////////////////////////////////////////////

// simple_variant

//  holds either a T or a T const*

template<typename T>

struct simple_variant

{

    simple_variant(T const *t)

      : is_rvalue(false)

    {

        *static_cast<T const **>(this->data.address()) = t;

    }

    simple_variant(T const &t)

      : is_rvalue(true)

    {

        ::new(this->data.address()) T(t);

    }

    simple_variant(simple_variant const &that)

      : is_rvalue(that.is_rvalue)

    {

        if(this->is_rvalue)

            ::new(this->data.address()) T(*that.get());

        else

            *static_cast<T const **>(this->data.address()) = that.get();

    }

    ~simple_variant()

    {

        if(this->is_rvalue)

            this->get()->~T();

    }

    T const *get() const

    {

        if(this->is_rvalue)

            return static_cast<T const *>(this->data.address());

        else

            return *static_cast<T const * const *>(this->data.address());

    }

private:

    enum size_type { size = sizeof(T) > sizeof(T*) ? sizeof(T) : sizeof(T*) };

    simple_variant &operator =(simple_variant const &); 

    bool const is_rvalue;

    aligned_storage<size> data;

};

// If the collection is an array or is noncopyable, it must be an lvalue.

// If the collection is a lightweight proxy, treat it as an rvalue

// BUGBUG what about a noncopyable proxy?

template<typename LValue, typename IsProxy>

inline BOOST_DEDUCED_TYPENAME boost::enable_if<boost::mpl::or_<LValue, IsProxy>, IsProxy>::type *

should_copy_impl(LValue *, IsProxy *, bool *)

{

    return 0;

}

// Otherwise, we must determine at runtime whether it's an lvalue or rvalue

inline bool *

should_copy_impl(boost::mpl::false_ *, boost::mpl::false_ *, bool *is_rvalue)

{

    return is_rvalue;

}

#endif

///////////////////////////////////////////////////////////////////////////////

// contain

//

template<typename T>

inline auto_any<T> contain(T const &t, boost::mpl::true_ *) // rvalue

{

    return t;

}

template<typename T>

inline auto_any<T *> contain(T &t, boost::mpl::false_ *) // lvalue

{

    // Cannot seem to get sunpro to handle addressof() with array types.

    #if BOOST_WORKAROUND(__SUNPRO_CC, BOOST_TESTED_AT(0x570))

    return &t;

    #else

    return boost::addressof(t);

    #endif

}

#ifdef BOOST_FOREACH_RUN_TIME_CONST_RVALUE_DETECTION

template<typename T>

auto_any<simple_variant<T> >

contain(T const &t, bool *rvalue)

{

    return *rvalue ? simple_variant<T>(t) : simple_variant<T>(&t);

}

#endif

/////////////////////////////////////////////////////////////////////////////

// begin

//

template<typename T, typename C>

inline auto_any<BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type>

begin(auto_any_t col, type2type<T, C> *, boost::mpl::true_ *) // rvalue

{

    return boost::begin(auto_any_cast<T, C>(col));

}

template<typename T, typename C>

inline auto_any<BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type>

begin(auto_any_t col, type2type<T, C> *, boost::mpl::false_ *) // lvalue

{

    typedef BOOST_DEDUCED_TYPENAME type2type<T, C>::type type;

    typedef BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type iterator;

    return iterator(boost::begin(derefof(auto_any_cast<type *, boost::mpl::false_>(col))));

}

#ifdef BOOST_FOREACH_RUN_TIME_CONST_RVALUE_DETECTION

template<typename T>

auto_any<BOOST_DEDUCED_TYPENAME foreach_iterator<T, const_>::type>

begin(auto_any_t col, type2type<T, const_> *, bool *)

{

    return boost::begin(*auto_any_cast<simple_variant<T>, boost::mpl::false_>(col).get());

}

#endif

///////////////////////////////////////////////////////////////////////////////

// end

//

template<typename T, typename C>

inline auto_any<BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type>

end(auto_any_t col, type2type<T, C> *, boost::mpl::true_ *) // rvalue

{

    return boost::end(auto_any_cast<T, C>(col));

}

template<typename T, typename C>

inline auto_any<BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type>

end(auto_any_t col, type2type<T, C> *, boost::mpl::false_ *) // lvalue

{

    typedef BOOST_DEDUCED_TYPENAME type2type<T, C>::type type;

    typedef BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type iterator;

    return iterator(boost::end(derefof(auto_any_cast<type *, boost::mpl::false_>(col))));

}

#ifdef BOOST_FOREACH_RUN_TIME_CONST_RVALUE_DETECTION

template<typename T>

auto_any<BOOST_DEDUCED_TYPENAME foreach_iterator<T, const_>::type>

end(auto_any_t col, type2type<T, const_> *, bool *)

{

    return boost::end(*auto_any_cast<simple_variant<T>, boost::mpl::false_>(col).get());

}

#endif

#ifndef BOOST_NO_FUNCTION_TEMPLATE_ORDERING

template<typename T, typename C>

inline auto_any<int>

end(auto_any_t col, type2type<T *, C> *, boost::mpl::true_ *) // null-terminated C-style strings

{

    return 0; // not used

}

#endif

///////////////////////////////////////////////////////////////////////////////

// done

//

template<typename T, typename C>

inline bool done(auto_any_t cur, auto_any_t end, type2type<T, C> *)

{

    typedef BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type iter_t;

    return auto_any_cast<iter_t, boost::mpl::false_>(cur) == auto_any_cast<iter_t, boost::mpl::false_>(end);

}

#ifndef BOOST_NO_FUNCTION_TEMPLATE_ORDERING

template<typename T, typename C>

inline bool done(auto_any_t cur, auto_any_t, type2type<T *, C> *) // null-terminated C-style strings

{

    return ! *auto_any_cast<T *, boost::mpl::false_>(cur);

}

#endif

///////////////////////////////////////////////////////////////////////////////

// next

//

template<typename T, typename C>

inline void next(auto_any_t cur, type2type<T, C> *)

{

    typedef BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type iter_t;

    ++auto_any_cast<iter_t, boost::mpl::false_>(cur);

}

///////////////////////////////////////////////////////////////////////////////

// deref

//

template<typename T, typename C>

inline BOOST_DEDUCED_TYPENAME foreach_reference<T, C>::type

deref(auto_any_t cur, type2type<T, C> *)

{

    typedef BOOST_DEDUCED_TYPENAME foreach_iterator<T, C>::type iter_t;

    return *auto_any_cast<iter_t, boost::mpl::false_>(cur);

}

} // namespace foreach_detail_

} // namespace boost

// A sneaky way to get the type of the collection without evaluating the expression

#define BOOST_FOREACH_TYPEOF(COL)                                                               \

    (true ? 0 : boost::foreach_detail_::encode_type(COL, boost::foreach_detail_::is_const_(COL)))

// returns true_* if the type is noncopyable

#define BOOST_FOREACH_IS_NONCOPYABLE(COL)                                                       \

    boost_foreach_is_noncopyable(                                                               \

        boost::foreach_detail_::to_ptr(COL)                                                     \

      , boost_foreach_argument_dependent_lookup_hack_value)

// returns true_* if the type is a lightweight proxy (and is not noncopyable)

#define BOOST_FOREACH_IS_LIGHTWEIGHT_PROXY(COL)                                                 \

    boost::foreach_detail_::and_(                                                               \

        boost::foreach_detail_::not_(BOOST_FOREACH_IS_NONCOPYABLE(COL))                         \

      , boost_foreach_is_lightweight_proxy(                                                     \

            boost::foreach_detail_::to_ptr(COL)                                                 \

          , boost_foreach_argument_dependent_lookup_hack_value))

#ifdef BOOST_FOREACH_COMPILE_TIME_CONST_RVALUE_DETECTION

///////////////////////////////////////////////////////////////////////////////

// R-values and const R-values supported here with zero runtime overhead

///////////////////////////////////////////////////////////////////////////////

// No variable is needed to track the rvalue-ness of the collection expression

# define BOOST_FOREACH_PREAMBLE()                                                               \

    /**/

// Evaluate the collection expression

# define BOOST_FOREACH_EVALUATE(COL)                                                            \

    (COL)

# define BOOST_FOREACH_SHOULD_COPY(COL)                                                         \

    (true ? 0 : boost::foreach_detail_::or_(                                                    \

        BOOST_FOREACH_IS_RVALUE(COL)                                                            \

      , BOOST_FOREACH_IS_LIGHTWEIGHT_PROXY(COL)))

#elif defined(BOOST_FOREACH_RUN_TIME_CONST_RVALUE_DETECTION)

///////////////////////////////////////////////////////////////////////////////

// R-values and const R-values supported here

///////////////////////////////////////////////////////////////////////////////

// Declare a variable to track the rvalue-ness of the collection expression

# define BOOST_FOREACH_PREAMBLE()                                                               \

    if (bool _foreach_is_rvalue = false) {} else

// Evaluate the collection expression, and detect if it is an lvalue or and rvalue

# define BOOST_FOREACH_EVALUATE(COL)                                                            \

    (true ? boost::foreach_detail_::make_probe((COL), _foreach_is_rvalue) : (COL))

// The rvalue/lvalue-ness of the collection expression is determined dynamically, unless

// type type is an array or is noncopyable or is non-const, in which case we know it's an lvalue.

// If the type happens to be a lightweight proxy, always make a copy.

# define BOOST_FOREACH_SHOULD_COPY(COL)                                                         \

    (boost::foreach_detail_::should_copy_impl(                                                  \

        true ? 0 : boost::foreach_detail_::or_(                                                 \

            boost::foreach_detail_::is_array_(COL)                                              \

          , BOOST_FOREACH_IS_NONCOPYABLE(COL)                                                   \

          , boost::foreach_detail_::not_(boost::foreach_detail_::is_const_(COL)))               \

      , true ? 0 : BOOST_FOREACH_IS_LIGHTWEIGHT_PROXY(COL)                                      \

      , &_foreach_is_rvalue))

#elif !defined(BOOST_FOREACH_NO_RVALUE_DETECTION)

///////////////////////////////////////////////////////////////////////////////

// R-values supported here, const R-values NOT supported here

///////////////////////////////////////////////////////////////////////////////

// No variable is needed to track the rvalue-ness of the collection expression

# define BOOST_FOREACH_PREAMBLE()                                                               \

    /**/

// Evaluate the collection expression

# define BOOST_FOREACH_EVALUATE(COL)                                                            \

    (COL)

// Determine whether the collection expression is an lvalue or an rvalue.

// NOTE: this gets the answer wrong for const rvalues.

# define BOOST_FOREACH_SHOULD_COPY(COL)                                                         \

    (true ? 0 : boost::foreach_detail_::or_(                                                    \

        boost::foreach_detail_::is_rvalue_((COL), 0)                                            \

      , BOOST_FOREACH_IS_LIGHTWEIGHT_PROXY(COL)))

#else

///////////////////////////////////////////////////////////////////////////////

// R-values NOT supported here

///////////////////////////////////////////////////////////////////////////////

// No variable is needed to track the rvalue-ness of the collection expression

# define BOOST_FOREACH_PREAMBLE()                                                               \

    /**/

// Evaluate the collection expression

# define BOOST_FOREACH_EVALUATE(COL)                                                            \

    (COL)

// Can't use rvalues with BOOST_FOREACH (unless they are lightweight proxies)

# define BOOST_FOREACH_SHOULD_COPY(COL)                                                         \

    (true ? 0 : BOOST_FOREACH_IS_LIGHTWEIGHT_PROXY(COL))

#endif

#define BOOST_FOREACH_CONTAIN(COL)                                                              \

    boost::foreach_detail_::contain(                                                            \

        BOOST_FOREACH_EVALUATE(COL)                                                             \

      , BOOST_FOREACH_SHOULD_COPY(COL))

#define BOOST_FOREACH_BEGIN(COL)                                                                \

    boost::foreach_detail_::begin(                                                              \

        _foreach_col                                                                            \

      , BOOST_FOREACH_TYPEOF(COL)                                                               \

      , BOOST_FOREACH_SHOULD_COPY(COL))

#define BOOST_FOREACH_END(COL)                                                                  \

    boost::foreach_detail_::end(                                                                \

        _foreach_col                                                                            \

      , BOOST_FOREACH_TYPEOF(COL)                                                               \

      , BOOST_FOREACH_SHOULD_COPY(COL))

#define BOOST_FOREACH_DONE(COL)                                                                 \

    boost::foreach_detail_::done(                                                               \

        _foreach_cur                                                                            \

      , _foreach_end                                                                            \

      , BOOST_FOREACH_TYPEOF(COL))

#define BOOST_FOREACH_NEXT(COL)                                                                 \

    boost::foreach_detail_::next(                                                               \

        _foreach_cur                                                                            \

      , BOOST_FOREACH_TYPEOF(COL))

#define BOOST_FOREACH_DEREF(COL)                                                                \

    boost::foreach_detail_::deref(                                                              \

        _foreach_cur                                                                            \

      , BOOST_FOREACH_TYPEOF(COL))

///////////////////////////////////////////////////////////////////////////////

// BOOST_FOREACH

//

//   For iterating over collections. Collections can be

//   arrays, null-terminated strings, or STL containers.

//   The loop variable can be a value or reference. For

//   example:

//

//   std::list<int> int_list(/*stuff*/);

//   BOOST_FOREACH(int &i, int_list)

//   {

//       /* 

//        * loop body goes here.

//        * i is a reference to the int in int_list.

//        */

//   }

//

//   Alternately, you can declare the loop variable first,

//   so you can access it after the loop finishes. Obviously,

//   if you do it this way, then the loop variable cannot be

//   a reference.

//

//   int i;

//   BOOST_FOREACH(i, int_list)

//       { ... }

//

#define BOOST_FOREACH(VAR, COL)                                                                 \

    BOOST_FOREACH_PREAMBLE()                                                                    \

    if (boost::foreach_detail_::auto_any_t _foreach_col = BOOST_FOREACH_CONTAIN(COL)) {} else   \

    if (boost::foreach_detail_::auto_any_t _foreach_cur = BOOST_FOREACH_BEGIN(COL)) {} else     \

    if (boost::foreach_detail_::auto_any_t _foreach_end = BOOST_FOREACH_END(COL)) {} else       \

    for (bool _foreach_continue = true;                                                         \

              _foreach_continue && !BOOST_FOREACH_DONE(COL);                                    \

              _foreach_continue ? BOOST_FOREACH_NEXT(COL) : (void)0)                            \

        if  (boost::foreach_detail_::set_false(_foreach_continue)) {} else                      \

        for (VAR = BOOST_FOREACH_DEREF(COL); !_foreach_continue; _foreach_continue = true)

#endif