/*

 * Copyright (c) 2005,2006 INRIA

 * All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 as

 * published by the Free Software Foundation;

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

 */

#ifndef CALLBACK_H

#define CALLBACK_H

#include "reference-list.h"

namespace ns3 {

/***

 * \internal

 * This code was originally written based on the techniques 

 * described in http://www.codeproject.com/cpp/TTLFunction.asp

 * It was subsequently rewritten to follow the architecture

 * outlined in "Modern C++ Design" by Andrei Alexandrescu in 

 * chapter 5, "Generalized Functors".

 *

 * This code uses:

 *   - default template parameters to saves users from having to

 *     specify empty parameters when the number of parameters

 *     is smaller than the maximum supported number

 *   - the pimpl idiom: the Callback class is passed around by 

 *     value and delegates the crux of the work to its pimpl

 *     pointer.

 *   - two pimpl implementations which derive from CallbackImpl

 *     FunctorCallbackImpl can be used with any functor-type

 *     while MemPtrCallbackImpl can be used with pointers to

 *     member functions.

 *   - a reference list implementation to implement the Callback's

 *     value semantics.

 *

 * This code most notably departs from the alexandrescu 

 * implementation in that it does not use type lists to specify

 * and pass around the types of the callback arguments.

 * Of course, it also does not use copy-destruction semantics

 * and relies on a reference list rather than autoPtr to hold

 * the pointer.

 */

class empty {};

// declare the CallbackImpl class

template <typename R, typename T1, typename T2, typename T3, typename T4, typename T5>

class CallbackImpl;

// define CallbackImpl for 0 params

template <typename R>

class CallbackImpl<R,empty,empty,empty,empty,empty> {

public:

};

// define CallbackImpl for 1 params

template <typename R, typename T1>

class CallbackImpl<R,T1,empty,empty,empty,empty> {

public:

};

// define CallbackImpl for 2 params

template <typename R, typename T1, typename T2>

class CallbackImpl<R,T1,T2,empty,empty,empty> {

public:

};

// define CallbackImpl for 3 params

template <typename R, typename T1, typename T2, typename T3>

class CallbackImpl<R,T1,T2,T3,empty,empty> {

public:

};

// define CallbackImpl for 4 params

template <typename R, typename T1, typename T2, typename T3, typename T4>

class CallbackImpl<R,T1,T2,T3,T4,empty> {

public:

};

// define CallbackImpl for 5 params

template <typename R, typename T1, typename T2, typename T3, typename T4, typename T5>

class CallbackImpl {

public:

};

// an impl for Functors:

template <typename T, typename R, typename T1, typename T2, typename T3, typename T4,typename T5>

class FunctorCallbackImpl : public CallbackImpl<R,T1,T2,T3,T4,T5> {

public:

private:

};

// an impl for pointer to member functions

template <typename OBJ_PTR, typename MEM_PTR, typename R, typename T1, typename T2, typename T3, typename T4, typename T5>

class MemPtrCallbackImpl : public CallbackImpl<R,T1,T2,T3,T4,T5> {

public:

private:

};

/**

 * \brief Callback template class

 *

 * This class template implements the Functor Design Pattern.

 * It is used to declare the type of a Callback:

 *  - the first non-optional template argument represents

 *    the return type of the callback.

 *  - the second optional template argument represents

 *    the type of the first argument to the callback.

 *  - the third optional template argument represents

 *    the type of the second argument to the callback.

 *  - the fourth optional template argument represents

 *    the type of the third argument to the callback.

 *  - the fifth optional template argument represents

 *    the type of the fourth argument to the callback.

 *  - the sixth optional template argument represents

 *    the type of the fifth argument to the callback.

 *

 * Callback instances are built with the \ref MakeCallback

 * template functions. Callback instances have POD semantics:

 * the memory they allocate is managed automatically, without

 * user intervention which allows you to pass around Callback

 * instances by value.

 *

 * Sample code which shows how to use this class template 

 * as well as the function templates \ref MakeCallback :

 * \include samples/main-callback.cc

 */

template<typename R, 

class Callback {

public:

private:

};

/**

 * \defgroup MakeCallback MakeCallback

 *

 */

/**

 * \ingroup MakeCallback

 * \param mem_ptr class method member pointer

 * \param objPtr class instance

 * \return a wrapper Callback

 * Build Callbacks for class method members which takes no arguments

 * and potentially return a value.

 */

template <typename OBJ, typename R>

Callback<R> MakeCallback (R (OBJ::*mem_ptr) (), OBJ *const objPtr) {

}

/**

 * \ingroup MakeCallback

 * \param mem_ptr class method member pointer

 * \param objPtr class instance

 * \return a wrapper Callback

 * Build Callbacks for class method members which takes one argument

 * and potentially return a value.

 */

template <typename OBJ, typename R, typename T1>

Callback<R,T1> MakeCallback (R (OBJ::*mem_ptr) (T1), OBJ *const objPtr) {

}

/**

 * \ingroup MakeCallback

 * \param mem_ptr class method member pointer

 * \param objPtr class instance

 * \return a wrapper Callback

 * Build Callbacks for class method members which takes two arguments

 * and potentially return a value.

 */

template <typename OBJ, typename R, typename T1, typename T2>

Callback<R,T1,T2> MakeCallback (R (OBJ::*mem_ptr) (T1,T2), OBJ *const objPtr) {

}

/**

 * \ingroup MakeCallback

 * \param mem_ptr class method member pointer

 * \param objPtr class instance

 * \return a wrapper Callback

 * Build Callbacks for class method members which takes three arguments

 * and potentially return a value.

 */

template <typename OBJ, typename R, typename T1,typename T2, typename T3>

Callback<R,T1,T2,T3> MakeCallback (R (OBJ::*mem_ptr) (T1,T2,T3), OBJ *const objPtr) {

}

/**

 * \ingroup MakeCallback

 * \param mem_ptr class method member pointer

 * \param objPtr class instance

 * \return a wrapper Callback

 * Build Callbacks for class method members which takes four arguments

 * and potentially return a value.

 */

template <typename OBJ, typename R, typename T1, typename T2, typename T3, typename T4>

Callback<R,T1,T2,T3,T4> MakeCallback (R (OBJ::*mem_ptr) (T1,T2,T3,T4), OBJ *const objPtr) {

}

/**

 * \ingroup MakeCallback

 * \param mem_ptr class method member pointer

 * \param objPtr class instance

 * \return a wrapper Callback

 * Build Callbacks for class method members which takes five arguments

 * and potentially return a value.

 */

template <typename OBJ, typename R, typename T1, typename T2, typename T3, typename T4,typename T5>

Callback<R,T1,T2,T3,T4,T5> MakeCallback (R (OBJ::*mem_ptr) (T1,T2,T3,T4,T5), OBJ *const objPtr) {

}

/**

 * \ingroup MakeCallback

 * \param fnPtr function pointer

 * \return a wrapper Callback

 * Build Callbacks for functions which takes no arguments

 * and potentially return a value.

 */

template <typename R>

Callback<R> MakeCallback (R (*fnPtr) ()) {

}

/**

 * \ingroup MakeCallback

 * \param fnPtr function pointer

 * \return a wrapper Callback

 * Build Callbacks for functions which takes one argument

 * and potentially return a value.

 */

template <typename R, typename T1>

Callback<R,T1> MakeCallback (R (*fnPtr) (T1)) {

}

/**

 * \ingroup MakeCallback

 * \param fnPtr function pointer

 * \return a wrapper Callback

 * Build Callbacks for functions which takes two arguments

 * and potentially return a value.

 */

template <typename R, typename T1, typename T2>

Callback<R,T1,T2> MakeCallback (R (*fnPtr) (T1,T2)) {

}

/**

 * \ingroup MakeCallback

 * \param fnPtr function pointer

 * \return a wrapper Callback

 * Build Callbacks for functions which takes three arguments

 * and potentially return a value.

 */

template <typename R, typename T1, typename T2,typename T3>

Callback<R,T1,T2,T3> MakeCallback (R (*fnPtr) (T1,T2,T3)) {

}

/**

 * \ingroup MakeCallback

 * \param fnPtr function pointer

 * \return a wrapper Callback

 * Build Callbacks for functions which takes four arguments

 * and potentially return a value.

 */

template <typename R, typename T1, typename T2,typename T3,typename T4>

Callback<R,T1,T2,T3,T4> MakeCallback (R (*fnPtr) (T1,T2,T3,T4)) {

}

/**

 * \ingroup MakeCallback

 * \param fnPtr function pointer

 * \return a wrapper Callback

 * Build Callbacks for functions which takes five arguments

 * and potentially return a value.

 */

template <typename R, typename T1, typename T2,typename T3,typename T4,typename T5>

Callback<R,T1,T2,T3,T4,T5> MakeCallback (R (*fnPtr) (T1,T2,T3,T4,T5)) {

}

/**

 * \ingroup MakeCallback

 * \return a wrapper Callback

 * Build a null callback which takes no arguments

 * and potentially return a value.

 */

template <typename R>

Callback<R> MakeNullCallback (void) {

}

/**

 * \ingroup MakeCallback

 * \return a wrapper Callback

 * Build a null callback which takes one argument

 * and potentially return a value.

 */

template <typename R, typename T1>

Callback<R,T1> MakeNullCallback (void) {

}

/**

 * \ingroup MakeCallback

 * \return a wrapper Callback

 * Build a null callback which takes two arguments

 * and potentially return a value.

 */

template <typename R, typename T1, typename T2>

Callback<R,T1,T2> MakeNullCallback (void) {

}

/**

 * \ingroup MakeCallback

 * \return a wrapper Callback

 * Build a null callback which takes three arguments

 * and potentially return a value.

 */

template <typename R, typename T1, typename T2,typename T3>

Callback<R,T1,T2,T3> MakeNullCallback (void) {

}

/**

 * \ingroup MakeCallback

 * \return a wrapper Callback

 * Build a null callback which takes four arguments

 * and potentially return a value.

 */

template <typename R, typename T1, typename T2,typename T3,typename T4>

Callback<R,T1,T2,T3,T4> MakeNullCallback (void) {

}

/**

 * \ingroup MakeCallback

 * \return a wrapper Callback

 * Build a null callback which takes five arguments

 * and potentially return a value.

 */

template <typename R, typename T1, typename T2,typename T3,typename T4,typename T5>

Callback<R,T1,T2,T3,T4,T5> MakeNullCallback (void) {

}

/**

 * The following is experimental code. It works but we have

 * not yet determined whether or not it is really useful and whether

 * or not we really want to use it.

 */

// an impl for Bound Functors:

template <typename T, typename R, typename TX, typename T1, typename T2, typename T3, typename T4,typename T5>

class BoundFunctorCallbackImpl : public CallbackImpl<R,T1,T2,T3,T4,T5> {

public:

private:

};

template <typename R, typename TX, typename T1>

Callback<R,T1> MakeBoundCallback (R (*fnPtr) (TX,T1), TX a) {

}

template <typename R, typename TX, typename T1, typename T2>

Callback<R,T1,T2> MakeBoundCallback (R (*fnPtr) (TX,T1,T2), TX a) {

}

template <typename R, typename TX, typename T1, typename T2,typename T3,typename T4>

Callback<R,T1,T2,T3,T4> MakeBoundCallback (R (*fnPtr) (TX,T1,T2,T3,T4), TX a) {