chapter10-37.cpp

C++STL程序员开发指南

//文件名:CHAPTER10-37.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( )
{
map <int, int, less<int> > m1;
   map <int, int, less<int> >::value_compare vc1 = m1.value_comp( );
   pair< map<int,int>::iterator, bool > pr1, pr2;
   
   pr1= m1.insert ( map <int, int> :: value_type ( 1, 10 ) );
   pr2= m1.insert ( map <int, int> :: value_type ( 2, 5 ) );
   if( vc1( *pr1.first, *pr2.first ) == true )   
   {      cout << "The element ( 1,10 ) precedes the element ( 2,5 )."<< endl;  }
   else   
   {      cout << "The element ( 1,10 ) does not precede the element ( 2,5 )."
           << endl;
   }
   if(vc1( *pr2.first, *pr1.first ) == true )
   {   cout << "The element ( 2,5 ) precedes the element ( 1,10 )."<< endl;   }
   else   
   { cout << "The element ( 2,5 ) does not precede the element ( 1,10 )."
           << endl;   }
}