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hash_multiset::count

Returns the number of elements in a hash_multiset whose key matches a parameter-specified key.

size_type count(
   const Key& _Key
) const;

Parameters

  • _Key
    The key of the elements to be matched from the hash_multiset.

Return Value

1 if the hash_multiset contains an element whose sort key matches the parameter key.

0 if the hash_multiset does not contain an element with a matching key.

Remarks

The member function returns the number of elements in the following range:

[lower_bound (_Key ), upper_bound (_Key ) ).

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

When compiling this example with the /Wp64 flag or on a 64-bit platform, compiler warning C4267 will be generated. For more information on this warning, see Compiler Warning (level 3) C4267.

// hash_multiset_count.cpp
// compile with: /EHsc
#define _DEFINE_DEPRECATED_HASH_CLASSES 0
#include <hash_set>
#include <iostream>

int main( )
{
    using namespace std;
    using namespace stdext;
    hash_multiset<int> hms1;
    hash_multiset<int>::size_type i;

    hms1.insert(1);
    hms1.insert(1);

    // Keys do not need to be unique in hash_multiset,
    // so duplicates may exist.
    i = hms1.count(1);
    cout << "The number of elements in hms1 with a sort key of 1 is: "
         << i << "." << endl;

    i = hms1.count(2);
    cout << "The number of elements in hms1 with a sort key of 2 is: "
         << i << "." << endl;
}

The number of elements in hms1 with a sort key of 1 is: 2.
The number of elements in hms1 with a sort key of 2 is: 0.

Requirements

Header: <hash_set>

Namespace: stdext

See Also

Concepts

hash_multiset Class

hash_multiset Members

Standard Template Library