ATL / WTL / STL

#include <iostream>
#include <map>

class ClassOne
{
public :
    int age;
    int sal;
} ;

typedef std::map<int, ClassOne> Map ;

int main()
{
    Map theMap;
    Map::iterator theIterator;

    for ( int i = 0; i < 1000; ++i )
    {
        ClassOne one ;
        one.age = 40 ;
        one.sal = 1000 ;
        theMap.insert ( Map::value_type ( i, one )) ;
    }

    theIterator = theMap.find(0);

    if ( theIterator != theMap.end ())
    {
        std::cout << "The index " << (*theIterator).first << std::endl ;
        std::cout << "The class, age = " << (*theIterator).second.age << ", sal = " << (*theIterator).second.sal << std::endl ;
    }

    return 0;
}

>#include <iostream>
#include <map>

class ClassTwo
{
private :
    int age;
    int sal;
public :
    ClassTwo () : age ( 0 ), sal ( 0 )
    {
    }
    void Set ( int a, int s )
    {
        age = a ;
        sal = s ;
    }
    int Age () const
    {
        return age ;
    }
    int Sal () const
    {
        return sal ;
    }
} ;

typedef std::map<int, ClassTwo> Map ;

int _tmain(int argc, _TCHAR* argv[])
{
    Map theMap;
    Map::iterator theIterator;

    for ( int i = 0; i < 1000; ++i )
    {
        std::pair<Map::iterator,bool> itp = theMap.insert ( Map::value_type ( i, ClassTwo ())) ;
        if ( itp.second )
        {
            theIterator = itp.first ;
            (*theIterator).second.Set ( 40, 1000 ) ;
        }            
    }

    theIterator = theMap.find(0);

    if ( theIterator != theMap.end ())
    {
        std::cout << "The index " << (*theIterator).first << std::endl ;
        std::cout << "The class, age = " << (*theIterator).second.age << ", sal = " << (*theIterator).second.sal << std::endl ;
    }

    return 0;
}