An example of bound C++ maps

The following example shows how to define a bound C++ map which can only contain maximum number of specified elements. This is just an approach and there will probably be better and more efficient approaches.

//Program tested on Microsoft Visual Studio 2008 - Zahid Ghadialy
//The example below shows a bound map. In a general C++ map you
//can add as many elements as required. In this case there can
//only be 10 elements in the map. If you try adding more it will
//generate an error
#include<iostream>
#include<map>
#include<string>
#include<assert.h>

using namespace std;

map<int, string> freq;
int a[10]={0,0,0,0,0,0,0,0,0,0};

int store_in_maps(string s)
{
  int i;
  for(i=0; i < 10; i++)
  {
    if (a[i]==0)
      break;
  }
  if(i==10)
  {
    cout<<"Sorry no more Ids available in the pool"<<endl;
    assert(0);
  }

  a[i]=1;
  freq[i] = s;
  return i;
}

int remove_from_map(string s)
{
  map<int, string>::const_iterator iter;
  for(iter=freq.begin(); iter != freq.end(); ++iter)
  {
    if(iter->second == s)
      break;
  }
  if(iter==freq.end())
  {
    cout<<"Cant find the string "<<s<<endl;
    return (-1);
  }
  a[iter->first]=0;
  return iter->first;
}


int main()
{
  store_in_maps("first");
  store_in_maps("second");
  store_in_maps("third");
  store_in_maps("fourth");
  store_in_maps("fifth");
  store_in_maps("sixth");
  store_in_maps("seventh");
  store_in_maps("eighth");
  store_in_maps("ninth");
  store_in_maps("tenth");
  remove_from_map("fifth");
  store_in_maps("eleventh");
  remove_from_map("zahid");
  remove_from_map("fourth");

  map<int, string>::const_iterator iter;
  for(iter=freq.begin(); iter != freq.end(); ++iter)
  {
    cout<<"First: "<<(iter->first)<<"     Second: "<<(iter->second)<<"\t\tPool value: "<<a[iter->first]<<endl;
  }

  return 0;
}

The output of the program is as follows: