hash_set::find
Returns an iterator addressing the location of an element in a hash_set that has a key equivalent to a specified key.
iterator find(
const Key& _Key
);
const_iterator find(
const Key& _Key
) const;
Parameters
- _Key
The argument key to be matched by the sort key of an element from the hash_set being searched.
Return Value
An iterator or const_iterator that addresses the location of an element equivalent to a specified key or that addresses the location succeeding the last element in the hash_set if no match is found for the key.
Remarks
The member function returns an iterator that addresses an element in the hash_set whose sort key is equivalent to the argument key under a binary predicate that induces an ordering based on a less-than comparability relation.
If the return value of find is assigned to a const_iterator, the hash_set object cannot be modified. If the return value of find is assigned to an iterator, the hash_set object can be modified.
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_set_find.cpp
// compile with: /EHsc
#define _DEFINE_DEPRECATED_HASH_CLASSES 0
#include <hash_set>
#include <iostream>
int main( )
{
using namespace std;
using namespace stdext;
hash_set <int> hs1;
hash_set <int> :: const_iterator hs1_AcIter, hs1_RcIter;
hs1.insert( 10 );
hs1.insert( 20 );
hs1.insert( 30 );
hs1_RcIter = hs1.find( 20 );
cout << "The element of hash_set hs1 with a key of 20 is: "
<< *hs1_RcIter << "." << endl;
hs1_RcIter = hs1.find( 40 );
// If no match is found for the key, end( ) is returned
if ( hs1_RcIter == hs1.end( ) )
cout << "The hash_set hs1 doesn't have an element "
<< "with a key of 40." << endl;
else
cout << "The element of hash_set hs1 with a key of 40 is: "
<< *hs1_RcIter << "." << endl;
// The element at a specific location in the hash_set can be found
// by using a dereferenced iterator addressing the location
hs1_AcIter = hs1.end( );
hs1_AcIter--;
hs1_RcIter = hs1.find( *hs1_AcIter );
cout << "The element of hs1 with a key matching "
<< "that of the last element is: "
<< *hs1_RcIter << "." << endl;
}
The element of hash_set hs1 with a key of 20 is: 20. The hash_set hs1 doesn't have an element with a key of 40. The element of hs1 with a key matching that of the last element is: 30.
Requirements
Header: <hash_set>
Namespace: stdext