#ifndef TCG_AUTO_H

#define TCG_AUTO_H

#include "base.h"

#include "traits.h"

/* \file    auto.h

  \brief    This file contains template classes able to perform special operations upon

            instance destruction.

  \details  These classes can be useful to enforce block-scoped operations at a block's

            entry point, considering that a block end can be far away, or the function

            could return abruptly at several different points.

*/

namespace tcg

{

//*******************************************************************************

//    tcg::auto_type  definition

//*******************************************************************************

struct _auto_type {

	mutable bool m_destruct;

public:

	_auto_type(bool destruct) : m_destruct(destruct) {}

	_auto_type(const _auto_type &other) : m_destruct(other.m_destruct)

	{

		other.m_destruct = false;

	}

	_auto_type &operator=(const _auto_type &other)

	{

		m_destruct = other.m_destruct, other.m_destruct = false;

		return *this;

	}

};

typedef const _auto_type &auto_type;

//*******************************************************************************

//    tcg::auto_func  definition

//*******************************************************************************

template <typename op=""></typename>

struct auto_zerary : public _auto_type {

	Op m_op;

public:

	auto_zerary(bool destruct = true) : _auto_type(destruct) {}

	~auto_zerary()

	{

		if (this->m_destruct)

			m_op();

	}

};

//--------------------------------------------------------------------

template <typename function_traits<op="" op,="" t="typename" typename="">::arg1_type></typename>

struct auto_unary : public _auto_type {

	T m_arg1;

	Op m_op;

public:

	auto_unary(bool destruct = true) : _auto_type(destruct) {}

	auto_unary(Op op, T arg, bool destruct = true)

		: _auto_type(destruct), m_arg1(arg), m_op(op) {}

	~auto_unary()

	{

		if (this->m_destruct)

			m_op(m_arg1);

	}

};

//--------------------------------------------------------------------

template <typename function_traits<op="" op,="" t1="typename" typename="">::arg1_type,</typename>

		  typename T2 = typename function_traits<op>::arg2_type></op>

struct auto_binary : public _auto_type {

	T1 m_arg1;

	T2 m_arg2;

	Op m_op;

public:

	auto_binary(bool destruct = true) : _auto_type(destruct) {}

	auto_binary(Op op, T1 arg1, T2 arg2, bool destruct = true)

		: _auto_type(destruct), m_arg1(arg1), m_arg2(arg2), m_op(op) {}

	~auto_binary()

	{

		if (this->m_destruct)

			m_op(m_arg1, m_arg2);

	}

};

//*******************************************************************************

//    Helper functions

//*******************************************************************************

template <typename op=""></typename>

auto_zerary<op> make_auto(Op op, bool destruct = true)</op>

{

	return auto_zerary<op>(op, destruct);</op>

}

template <typename op,="" t="" typename=""></typename>

auto_unary<op> make_auto(Op op, T &arg1, bool destruct = true)</op>

{

	return auto_unary<op>(op, arg1, destruct);</op>

}

template <typename op,="" t="" typename=""></typename>

auto_unary<op> make_auto(Op op, const T &arg1, bool destruct = true)</op>

{

	return auto_unary<op>(op, arg1, destruct);</op>

}

template <typename op,="" t1,="" t2="" typename=""></typename>

auto_binary<op> make_auto(Op op, T1 &arg1, T2 &arg2, bool destruct = true)</op>

{

	return auto_binary<op>(op, arg1, arg2, destruct);</op>

}

template <typename op,="" t1,="" t2="" typename=""></typename>

auto_binary<op> make_auto(Op op, const T1 &arg1, T2 &arg2, bool destruct = true)</op>

{

	return auto_binary<op>(op, arg1, arg2, destruct);</op>

}

template <typename op,="" t1,="" t2="" typename=""></typename>

auto_binary<op> make_auto(Op op, T1 &arg1, const T2 &arg2, bool destruct = true)</op>

{

	return auto_binary<op>(op, arg1, arg2, destruct);</op>

}

template <typename op,="" t1,="" t2="" typename=""></typename>

auto_binary<op> make_auto(Op op, const T1 &arg1, const T2 &arg2, bool destruct = true)</op>

{

	return auto_binary<op>(op, arg1, arg2, destruct);</op>

}

//*******************************************************************************

//    tcg::auto_reset  definition

//*******************************************************************************

template <typename t="" t,="" val=""></typename>

class auto_reset

{

	typedef T var_type;

public:

	var_type &m_var;

public:

	auto_reset(var_type &var) : m_var(var) {}

	~auto_reset() { m_var = val; }

private:

	auto_reset(const auto_reset &);

	auto_reset &operator=(const auto_reset &);

};

//*******************************************************************************

//    tcg::auto_backup  definition

//*******************************************************************************

template <typename t=""></typename>

struct auto_backup {

	typedef T var_type;

public:

	var_type m_backup;

	var_type *m_original;

public:

	auto_backup() : m_original() {}

	auto_backup(var_type &original) : m_original(&original), m_backup(original) {}

	auto_backup(var_type *original) : m_original(original)

	{

		if (m_original)

			m_backup = *m_original;

	}

	~auto_backup()

	{

		if (m_original)

			*m_original = m_backup;

	}

	void reset(T &original)

	{

		m_original = &original;

		m_backup = original;

	}

	void reset(T *original)

	{

		m_original = original;

		if (m_original)

			m_backup = *original;

	}

	T *release()

	{

		T *original = m_original;

		m_original = 0;

		return original;

	}

private:

	auto_backup(const auto_backup &);

	auto_backup &operator=(const auto_backup &);

};

} // namespace tcg

#endif //TCG_AUTO_H