hash_map::empty
Tests if a hash_map is empty.
bool empty( ) const;
Return Value
true if the hash_map is empty; false if the hash_map is nonempty.
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_map_empty.cpp
// compile with: /EHsc
#define _DEFINE_DEPRECATED_HASH_CLASSES 0
#include <hash_map>
#include <iostream>
int main( )
{
using namespace std;
using namespace stdext;
hash_map <int, int> hm1, hm2;
typedef pair <int, int> Int_Pair;
hm1.insert ( Int_Pair ( 1, 1 ) );
if ( hm1.empty( ) )
cout << "The hash_map hm1 is empty." << endl;
else
cout << "The hash_map hm1 is not empty." << endl;
if ( hm2.empty( ) )
cout << "The hash_map hm2 is empty." << endl;
else
cout << "The hash_map hm2 is not empty." << endl;
}
The hash_map hm1 is not empty.
The hash_map hm2 is empty.
Requirements
Header: <hash_map>
Namespace: stdext