chapter10-2.cpp

C++STL程序员开发指南

//文件名:CHAPTER10-2.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( )
{
   typedef pair <int, int> Int_Pair;
   multimap <int, int>::iterator m1_Iter, m3_Iter, m4_Iter, m5_Iter, m6_Iter;
   multimap <int, int, greater<int> >::iterator m2_Iter;
   // Create an empty multimap m0 of key type integer
   multimap <int, int> m0;
   // Create an empty multimap m1 with the key comparison
   // function of less than, then insert 4 elements
   multimap <int, int, less<int> > m1;
   m1.insert( Int_Pair( 1, 10 ) );
   m1.insert( Int_Pair( 2, 20 ) );
   m1.insert( Int_Pair( 3, 30 ) );
   m1.insert( Int_Pair( 4, 40 ) );
   // Create an empty multimap m2 with the key comparison
   // function of geater than, then insert 2 elements
   multimap <int, int, greater<int> > m2;
   m2.insert( Int_Pair( 1, 10 ) );
   m2.insert( Int_Pair( 2, 20 ) );
   // Create a multimap m3 with the allocator of multimap m1
   multimap <int, int>::allocator_type m1_Alloc;
   m1_Alloc = m1.get_allocator( );
   multimap <int, int> m3( less<int>( ), m1_Alloc );
   m3.insert( Int_Pair( 3, 30 ) );
   // Create a copy, multimap m4, of multimap m1
   multimap <int, int> m4( m1 );
   // Create a multimap m5 by copying the range m1[_First, _Last)
   multimap <int, int>::const_iterator m1_bcIter, m1_ecIter;
   m1_bcIter = m1.begin( );
   m1_ecIter = m1.begin( );
   m1_ecIter++;
   m1_ecIter++;
   //multimap <int, int> m5( m1_bcIter, m1_ecIter );
   multimap <int, int> m5;
   m5.insert( Int_Pair( 1, 10 ) );
   m5.insert( Int_Pair( 2, 20 ) );
   // Create a multimap m6 by copying the range m4[_First, _Last)
   // and with the allocator of multimap m2
   multimap <int, int>::allocator_type m2_Alloc;
   m2_Alloc = m2.get_allocator( );
//   multimap <int, int> m6(m4.begin( ), ++m4.begin( ), less<int>( ), m2_Alloc);
   multimap <int, int> m6;
   m6.insert( Int_Pair( 2, 20 ) );
   m6.insert( Int_Pair( 1, 10 ) );

   cout << "m1 =";
   for ( m1_Iter = m1.begin( ); m1_Iter != m1.end( ); m1_Iter++ )
      cout << " " << m1_Iter -> second;
   cout << endl;
   cout << "m2 =";
   for ( m2_Iter = m2.begin( ); m2_Iter != m2.end( ); m2_Iter++ )
      cout << " " << m2_Iter -> second;
   cout << endl;
   cout << "m3 =";
   for ( m3_Iter = m3.begin( ); m3_Iter != m3.end( ); m3_Iter++ )
      cout << " " << m3_Iter -> second;
   cout << endl;
   cout << "m4 =";
   for ( m4_Iter = m4.begin( ); m4_Iter != m4.end( ); m4_Iter++ )
      cout << " " << m4_Iter -> second;
   cout << endl;
   cout << "m5 =";
   for ( m5_Iter = m5.begin( ); m5_Iter != m5.end( ); m5_Iter++ )
      cout << " " << m5_Iter -> second;
   cout << endl;
   cout << "m6 =";
   for ( m6_Iter = m6.begin( ); m6_Iter != m6.end( ); m6_Iter++ )
      cout << " " << m6_Iter -> second;
   cout << endl;
}