rosaria/Legacy/Aria/advanced/functorListsAndStdAlgorithms.cpp

/*
Adept MobileRobots Robotics Interface for Applications (ARIA)
Copyright (C) 2004, 2005 ActivMedia Robotics LLC
Copyright (C) 2006, 2007, 2008, 2009, 2010 MobileRobots Inc.
Copyright (C) 2011, 2012, 2013 Adept Technology

     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2 of the License, or
     (at your option) any later version.

     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

If you wish to redistribute ARIA under different terms, contact 
Adept MobileRobots for information about a commercial version of ARIA at 
robots@mobilerobots.com or 
Adept MobileRobots, 10 Columbia Drive, Amherst, NH 03031; +1-603-881-7960
*/
/*
 * This example shows how to use adapters to use STL algorithms
 * with ARIA functors.
 * An adapter is an STL function object that calls a method pointer
 * (like &ArFunctor::invoke) on whatever object it's applied to when
 * invoked with the STL convention (which uses operator().)
 *
 * This lets you use ARIA functors in STL algorithms (which normally
 * only work on STL function objects):
 *
 *  STL Algorithm -> STL Function Pointer Adapter -> ARIA Functor -> 
 *    ARIA Functor Target Method
 *
 *
 * Things end up looking kind of redundant
 *   
*/


#include <string>
#include <list>
#include <set>
#include <algorithm>
#include <iostream>

#include "Aria.h"


/*
  This is the class that contains some methods to use as callbacks targets.
*/
class CallbackClass
{
public:

  void callback1();
  void callback2(int i);
  bool callback3(const char *str);
};

void CallbackClass::callback1()
{
  printf("Invoked callback1\n");
}

void CallbackClass::callback2(int i)
{
  printf("Invoked callback2 with argument of '%d'\n", i);
}

bool CallbackClass::callback3(const char *str)
{
  printf("Invoked callback3 with argument of '%s'\n", str);
  return(true);
}


// But not all functor targets need to be in a class:
void globalFunction() 
{
  std::cout << "Invoked globalFunction." << std::endl;
}

int main()
{
  CallbackClass cb;


  // For functors with no arguments:
  std::list<ArFunctor*> functors;
  ArFunctorC<CallbackClass> functor1(cb, &CallbackClass::callback1);
  functors.push_back(&functor1);
  functors.push_back(&functor1);
  functors.push_back(&functor1);
  std::for_each(functors.begin(), functors.end(), 
      std::mem_fun(&ArFunctor::invoke));

  // For functors with arguments, give mem_fun template parameters.
  std::list<ArFunctor1<int>*> functorsWithArg;
  ArFunctor1C<CallbackClass, int> functor2(cb, &CallbackClass::callback2);
  std::mem_fun1_t<void, ArFunctor1<int>, int> f(&ArFunctor1<int>::invoke);
  functorsWithArg.push_back(&functor2);
  functorsWithArg.push_back(&functor2);
  functorsWithArg.push_back(&functor2);
  std::for_each(functorsWithArg.begin(), functorsWithArg.end(), std::bind2nd(f, 42));

  // You can use other STL algorithms if your functor returns something.
  // count_if will invoke each functor, and return the number of functor
  // invocations that returned true (in this case, 3, since they will 
  // always return true)
  std::list<ArRetFunctor1<bool, const char*>*> functorsWithRet;
  ArRetFunctor1C<bool, CallbackClass, const char *>
    functor3(cb, &CallbackClass::callback3);
  std::mem_fun1_t<bool, ArRetFunctor1<bool, const char*>, const char*> rf(&ArRetFunctor1<bool, const char*>::invokeR);
  functorsWithRet.push_back(&functor3);
  functorsWithRet.push_back(&functor3);
  functorsWithRet.push_back(&functor3);
  int c = std::count_if(functorsWithRet.begin(), functorsWithRet.end(), std::bind2nd(rf, "testing"));
  std::cout << "Count=" << c << std::endl;

  return(0);
}