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CodeBlocksPortable/Borland/BCC55/Examples/StdLib/memfunc.cpp

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#include "stlexam.h"
#pragma hdrstop
/**************************************************************************
*
* memfunc.cpp - Example program for mem_fun and other member function
* pointer wrappers. See Class Reference Section.
*
***************************************************************************
*
* (c) Copyright 1994, 1998 Rogue Wave Software, Inc.
* ALL RIGHTS RESERVED
*
* The software and information contained herein are proprietary to, and
* comprise valuable trade secrets of, Rogue Wave Software, Inc., which
* intends to preserve as trade secrets such software and information.
* This software is furnished pursuant to a written license agreement and
* may be used, copied, transmitted, and stored only in accordance with
* the terms of such license and with the inclusion of the above copyright
* notice. This software and information or any other copies thereof may
* not be provided or otherwise made available to any other person.
*
* Notwithstanding any other lease or license that may pertain to, or
* accompany the delivery of, this computer software and information, the
* rights of the Government regarding its use, reproduction and disclosure
* are as set forth in Section 52.227-19 of the FARS Computer
* Software-Restricted Rights clause.
*
* Use, duplication, or disclosure by the Government is subject to
* restrictions as set forth in subparagraph (c)(1)(ii) of the Rights in
* Technical Data and Computer Software clause at DFARS 252.227-7013.
* Contractor/Manufacturer is Rogue Wave Software, Inc.,
* P.O. Box 2328, Corvallis, Oregon 97339.
*
* This computer software and information is distributed with "restricted
* rights." Use, duplication or disclosure is subject to restrictions as
* set forth in NASA FAR SUP 18-52.227-79 (April 1985) "Commercial
* Computer Software-Restricted Rights (April 1985)." If the Clause at
* 18-52.227-74 "Rights in Data General" is specified in the contract,
* then the "Alternate III" clause applies.
*
**************************************************************************/
#include <vector>
#include <functional>
#include <algorithm>
#ifdef _RW_STD_IOSTREAM
#include <iostream>
#else
#include <iostream.h>
#endif
#ifndef _RWSTD_NO_NAMESPACE
using namespace std;
#endif
//
// Very large city class
//
class MegaPolis
{
public:
MegaPolis(char* s = 0 , float n = 0):cityName(s),population(n) {;}
// The following function cannot return void due to limitations in
// some current C++ implementations.
virtual size_t byPopulation()
{
cout<<cityName<<"(MegaPolis)"<<"\t\t\t"<<population<<endl;
return 0;
}
float population;
protected:
char* cityName;
};
//
// City and surrounding area class
//
class MetroPolis : public MegaPolis
{
public:
MetroPolis(char* s = 0 , float n = 0):MegaPolis(s,n){;}
virtual size_t byPopulation()
{
cout<<cityName<<"(MetroPolis)"<<"\t\t\t"<<population<<endl;
return 0;
}
};
//
// Functor compares the size of two MeagPolis classes
//
struct GreaterPopulation
{
bool operator()(MegaPolis* m1, MegaPolis* m2)
{
return m1->population<m2->population;
}
} greater_pop;
int main()
{
//
// Create a vector of very lareg cities
//
vector<MegaPolis*, allocator<MegaPolis*> > cityList;
cityList.push_back(new MegaPolis ("Calcutta",35));
cityList.push_back(new MegaPolis ("Tokyo",20));
cityList.push_back(new MegaPolis ("Delhi",10));
cityList.push_back(new MegaPolis ("Bombay",15));
cityList.push_back(new MetroPolis ("Cairo",5));
cityList.push_back(new MetroPolis ("New York",2.5));
cityList.push_back(new MetroPolis ("Los Angeles",3));
cityList.push_back(new MetroPolis ("Jakarta",1.5));
//
// Now use mem_fun to pass byPopulation member function
// of MegaPolis to the for_each function.
//
cout<<"City "<<" Population (in millions) "<<endl;
cout<<"----- "<<" -----------------------"<<endl;
for_each(cityList.begin(),cityList.end(),mem_fun(&MegaPolis::byPopulation));
cout<<"..............After sorting..........................."<<endl;
stable_sort(cityList.begin(),cityList.end(),greater_pop);
for_each(cityList.begin(),cityList.end(),mem_fun(&MegaPolis::byPopulation));
return 0;
}