chapter10-4.cpp

C++STL程序员开发指南

//文件名:CHAPTER10-4.cpp
#include <map>
#include <iostream>
#if _MSC_VER > 1020   // if VC++ version is > 4.2
   using namespace std;  // std c++ libs implemented in std
#endif
void main( )
{
   multimap <int, int> m1;
   int i;
   multimap <int, int> :: iterator m1_Iter;
   multimap <int, int> :: const_iterator m1_cIter;
   typedef pair <int, int> Int_Pair;
   m1.insert ( Int_Pair ( 0, 0 ) );
   m1.insert ( Int_Pair ( 1, 1 ) );
   m1.insert ( Int_Pair ( 2, 4 ) );
   m1_cIter = m1.begin ( );
   cout << "The first element of m1 is " << m1_cIter -> first << endl;
   m1_Iter = m1.begin ( );
   m1.erase ( m1_Iter );
   // The following 2 lines would err as the iterator is const
   // m1_cIter = m1.begin ( );
   // m1.erase ( m1_cIter );
   m1_cIter = m1.begin( );
   cout << "First element of m1 is now " << m1_cIter -> first << endl;
}