// A stripped down version of FOREACH for
// illustration purposes. NOT FOR GENERAL USE.
// For a complete implementation, see BOOST_FOREACH at
// http://boost-sandbox.sourceforge.net/vault/index.php?directory=eric_niebler
//
// 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)

#include <vector>
#include <iostream>

///////////////////////////////////////////////////////////////////////////////
// auto_any

struct auto_any_base
{
    operator bool() const { return false; }
};

template<typename T>
struct auto_any : auto_any_base
{
    auto_any(T const& t) : item(t) {}
    mutable T item;
};

template<typename T>
T& auto_any_cast(auto_any_base const& any)
{
    return static_cast<auto_any<T> const&>(any).item;
}

///////////////////////////////////////////////////////////////////////////////
// FOREACH helper function

template<typename T>
auto_any<typename T::const_iterator> begin(T const& t)
{
    return t.begin();
}

template<typename T>
auto_any<typename T::const_iterator> end(T const& t)
{
    return t.end();
}

template<typename T>
bool done(auto_any_base const& cur, auto_any_base const& end, T const&)
{
    typedef typename T::const_iterator iter_type;
    return auto_any_cast<iter_type>(cur) == auto_any_cast<iter_type>(end);
}

template<typename T>
void next(auto_any_base const& cur, T const&)
{
    typedef typename T::const_iterator iter_type;
    ++auto_any_cast<iter_type>(cur);
}

template<typename T>
typename T::const_reference deref(auto_any_base const& cur, T const&)
{
    typedef typename T::const_iterator iter_type;
    return *auto_any_cast<iter_type>(cur);
}

///////////////////////////////////////////////////////////////////////////////
// FOREACH

#define FOREACH(item, container)                            \
    if(auto_any_base const& b = begin(container)) {} else   \
    if(auto_any_base const& e = end(container)) {} else     \
    for(bool more = true;                                   \
        more && !done(b,e,container);                       \
        more ? next(b,container) : (void)0)                 \
        if (more = false) {} else                           \
        for(item = deref(b,container); !more; more = true)


std::vector<double> const container(3,1.0);

std::vector<double> const& get_cont()
{
    std::cout << "here\n";
    return container;
}

int main()
{
    FOREACH(double d, get_cont())
    {
        std::cout << d << '\n';
    }

    return 0;
}