A filter to remove white-space characters at the ends of lines.
#include <iostream>
#include <string>
using namespace std;
void cutline( void );         
string line;                  
int main()
{
   while( getline(cin, line)) {
     cutline();               
     cout << line << endl;    
   }
   return 0;
} 

void cutline()
{
   int i = line.size();       
                              
   while( i-- >= 0 )
     if(   line[i] != ' ' && line[i] != '\t' )
       break;                   
   line.resize(++i);            
}