hash_multimap::lower_bound

Returns an iterator to the first element in a hash_multimap with a key that is equal to or greater than a specified key.

iterator lower_bound( 
   const Key& _Key 
); 
const_iterator lower_bound( 
   const Key& _Key 
) const;

Parameters

• _Key
  The argument key to be compared with the sort key of an element from the hash_multimap being searched.

Return Value

An iterator or const_iterator that addresses the location of an element in a hash_multimap with a key that is equal to or greater than the argument key, or that addresses the location succeeding the last element in the hash_multimap if no match is found for the key.

If the return value of lower_bound is assigned to a const_iterator, the hash_multimap object cannot be modified. If the return value of lower_bound is assigned to an iterator, the hash_multimap object can be modified.

Remarks

In Visual C++ .NET 2003, members of the <hash_map> and <hash_set> header files are no longer in the std namespace, but rather have been moved into the stdext namespace. See The stdext Namespace for more information.

Example

// hash_multimap_lower_bound.cpp
// compile with: /EHsc
#include <hash_map>
#include <iostream>

int main( )
{
   using namespace std;
   using namespace stdext;
   hash_multimap <int, int> hm1;
   hash_multimap <int, int> :: const_iterator hm1_AcIter, 
      hm1_RcIter;
   typedef pair <int, int> Int_Pair;

   hm1.insert ( Int_Pair ( 1, 10 ) );
   hm1.insert ( Int_Pair ( 2, 20 ) );
   hm1.insert ( Int_Pair ( 3, 20 ) );
   hm1.insert ( Int_Pair ( 3, 30 ) );

   hm1_RcIter = hm1.lower_bound( 2 );
   cout << "The element of hash_multimap hm1 with a key of 2 is: "
        << hm1_RcIter -> second << "." << endl;

   hm1_RcIter = hm1.lower_bound( 3 );
   cout << "The first element of hash_multimap hm1 with a key of 3 is: "
        << hm1_RcIter -> second << "." << endl;

   // If no match is found for the key, end( ) is returned
   hm1_RcIter = hm1.lower_bound( 4 );

   if ( hm1_RcIter == hm1.end( ) )
      cout << "The hash_multimap hm1 doesn't have an element "
           << "with a key of 4." << endl;
   else
      cout << "The element of hash_multimap hm1 with a key of 4 is: "
           << hm1_RcIter -> second << "." << endl;

   // The element at a specific location in the hash_multimap can be
   // found using a dereferenced iterator addressing the location
   hm1_AcIter = hm1.end( );
   hm1_AcIter--;
   hm1_RcIter = hm1.lower_bound( hm1_AcIter -> first );
   cout << "The first element of hm1 with a key matching"
        << endl << " that of the last element is: "
        << hm1_RcIter -> second << "." << endl;

   // Note that the first element with a key equal to
   // the key of the last element is not the last element
   if ( hm1_RcIter == --hm1.end( ) )
      cout << "This is the last element of hash_multimap hm1."
           << endl;
   else
      cout << "This is not the last element of hash_multimap hm1."
           << endl;
}

The element of hash_multimap hm1 with a key of 2 is: 20.
The first element of hash_multimap hm1 with a key of 3 is: 20.
The hash_multimap hm1 doesn't have an element with a key of 4.
The first element of hm1 with a key matching
 that of the last element is: 20.
This is not the last element of hash_multimap hm1.

Requirements

Header: <hash_map>

Namespace: stdext

See Also

Reference

hash_multimap Class

Standard Template Library