#pragma once
#include <map>
#include <boost/noncopyable.hpp>
#include <boost/thread/thread.hpp>
#include <boost/thread/mutex.hpp>


namespace boost_ext {


namespace detail {
/** Emulation of "thread_local" storage keyword.
    Copyright (c) 2013, Fredrik Orderud. */
template <class T>
class thread_local_impl : boost::noncopyable {
public:
	thread_local_impl (T default) : m_default(default) {
	}

	operator T () const {
        using namespace boost;
		unique_lock<mutex> lock(m_mutex);

        std::map<thread::id,T>::const_iterator it = m_map.find(this_thread::get_id());
		if (it == m_map.end())
			return m_default;
        
        return it->second;
	}

    thread_local_impl<T> & operator = (const T & val) {
        using namespace boost;
		unique_lock<mutex> lock(m_mutex);

		m_map[this_thread::get_id()] = val;
        return *this;
	}

private:
	const T                       m_default;
	std::map<boost::thread::id,T> m_map;
	mutable boost::mutex          m_mutex;
};

} // namespace detail


/** Work-around for missing "thread_local" keyword support in non-C++11 compilers.
    The macro translates into either "thread_local", "__declspec(thread)", "__thread" or
    a thread_local emulation, depending on platform and compiler.
    Copyright (c) 2013, Fredrik Orderud. */ 
#ifndef BOOST_THREAD_LOCAL_RESTRICTED
#  if __cplusplus >= 201103L // C++11 conformant compiler
#    define BOOST_THREAD_LOCAL_RESTRICTED(T) thread_local T
#  elif defined _WIN32       // Windows platform
#    if (defined _MSC_VER) && (_MSC_VER >= 1700) && (!defined _USING_V110_SDK71_) // MSVC >=11 in non-WinXP compatible mode
#      define BOOST_THREAD_LOCAL_RESTRICTED(T) __declspec(thread) T
#    else
#      define BOOST_THREAD_LOCAL_RESTRICTED(T) detail::thread_local_impl<T>
#    endif
#  else // non-Windows platform
#    define BOOST_THREAD_LOCAL_RESTRICTED(T) __thread T
#  endif
#endif

} // namespace boost_ext