#pragma once

#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,</op>

                          bool destruct = true) {

  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,</op>

                          bool destruct = true) {

  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,</op>

                          bool destruct = true) {

  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