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<H1>hash_multimap<Key, Data, HashFcn, EqualKey, Alloc></H1>
<Table CellPadding=0 CellSpacing=0 width=100%>
<TR>
<TD Align=left><Img src = "containers.gif" Alt="" WIDTH = "194" HEIGHT = "38" ></TD>
<TD Align=right><Img src = "type.gif" Alt="" WIDTH = "194" HEIGHT = "39" ></TD>
</TR>
<TR>
<TD Align=left VAlign=top><b>Category</b>: containers</TD>
<TD Align=right VAlign=top><b>Component type</b>: type</TD>
</TR>
</Table>
<h3>Description</h3>
<tt>Hash_multimap</tt> is a
<A href="HashedAssociativeContainer.html">Hashed Associative Container</A>
that associates objects of type <tt>Key</tt> with
objects of type <tt>Data</tt>. <tt>Hash_multimap</tt> is a
<A href="PairAssociativeContainer.html">Pair Associative Container</A>,
meaning that its value type is
<tt><A href="pair.html">pair</A><const Key, Data></tt>. It is also a
<A href="MultipleAssociativeContainer.html">Multiple Associative Container</A>,
meaning that there is no limit on the number of
elements whose keys may compare equal using <tt>EqualKey</tt>.
<P>
Looking up an element in a <tt>hash_multimap</tt> by its key is
efficient, so <tt>hash_multimap</tt> is useful for
"dictionaries" where the order of elements is irrelevant.
If it is important for the elements to be in a particular order,
however, then <tt><A href="Multimap.html">multimap</A></tt> is more
appropriate.
<h3>Example</h3>
<pre>
struct eqstr
{
bool operator()(const char* s1, const char* s2) const
{
return strcmp(s1, s2) == 0;
}
};
typedef hash_multimap<const char*, int, hash<const char*>, eqstr> map_type;
void lookup(const map_type& Map, const char* str)
{
cout << str << ": ";
pair<map_type::const_iterator, map_type::const_iterator> p =
Map.equal_range(str);
for (map_type::const_iterator i = p.first; i != p.second; ++i)
cout << (*i).second << " ";
cout << endl;
}
int main()
{
map_type M;
M.insert(map_type::value_type("H", 1));
M.insert(map_type::value_type("H", 2));
M.insert(map_type::value_type("C", 12));
M.insert(map_type::value_type("C", 13));
M.insert(map_type::value_type("O", 16));
M.insert(map_type::value_type("O", 17));
M.insert(map_type::value_type("O", 18));
M.insert(map_type::value_type("I", 127));
lookup(M, "I");
lookup(M, "O");
lookup(M, "Rn");
}
</pre>
<h3>Definition</h3>
<tt>Hash_multimap</tt> is declared in
<A href="hash_map.h">hash_map.h</A>. The implementation is in
<A href="hash_map.h">hash_map.h</A>
and <A href="hashtable.h">hashtable.h</A>.
<h3>Template parameters</h3>
<Table border>
<TR>
<TH>
Parameter
</TH>
<TH>
Description
</TH>
<TH>
Default
</TH>
</TR>
<TR>
<TD VAlign=top>
<tt>Key</tt>
</TD>
<TD VAlign=top>
The hash_multimap's key type. This is also defined as <tt>hash_multimap::key_type</tt>.
</TD>
<TD VAlign=top>
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>Data</tt>
</TD>
<TD VAlign=top>
The hash_multimap's data type. This is also defined as <tt>hash_multimap::data_type</tt>.
</TD>
<TD VAlign=top>
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>HashFcn</tt>
</TD>
<TD VAlign=top>
The <A href="HashFunction.html">hash function</A> used by the hash_multimap. This is also defined
as <tt>hash_multimap::hasher</tt>.
</TD>
<TD VAlign=top>
<tt><A href="hash.html">hash</A><Key></tt>
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>EqualKey</tt>
</TD>
<TD VAlign=top>
The hash_multimap's key equality function: a <A href="BinaryPredicate.html">binary predicate</A> that
determines whether two keys are equal. This is also defined as
<tt>hash_multimap::key_equal</tt>.
</TD>
<TD VAlign=top>
<tt><A href="equal_to.html">equal_to</A><Key></tt>
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>Alloc</tt>
</TD>
<TD VAlign=top>
The <tt>hash_set</tt>'s allocator, used for all internal memory management.
</TD>
<TD VAlign=top>
<tt><A href="Allocators.html">alloc</A></tt>
</TD>
</tr>
</table>
<h3>Model of</h3>
<A href="MultipleHashedAssociativeContainer.html">Multiple Hashed Associative Container</A>,
<A href="PairAssociativeContainer.html">Pair Associative Container</A>
<h3>Type requirements</h3>
<UL>
<LI>
<tt>Key</tt> is <A href="Assignable.html">Assignable</A>.
<LI>
<tt>EqualKey</tt> is a <A href="BinaryPredicate.html">Binary Predicate</A> whose argument type
is <tt>Key</tt>.
<LI>
<tt>EqualKey</tt> is an equivalence relation.
<LI>
<tt>Alloc</tt> is an <A href="Allocators.html">Allocator</A>.
</UL>
<h3>Public base classes</h3>
None.
<h3>Members</h3>
<Table border>
<TR>
<TH>
Member
</TH>
<TH>
Where defined
</TH>
<TH>
Description
</TH>
</TR>
<TR>
<TD VAlign=top>
<tt>key_type</tt>
</TD>
<TD VAlign=top>
<A href="AssociativeContainer.html">Associative Container</A>
</TD>
<TD VAlign=top>
The <tt>hash_multimap</tt>'s key type, <tt>Key</tt>.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>data_type</tt>
</TD>
<TD VAlign=top>
<A href="PairAssociativeContainer.html">Pair Associative Container</A>
</TD>
<TD VAlign=top>
The type of object associated with the keys.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>value_type</tt>
</TD>
<TD VAlign=top>
<A href="PairAssociativeContainer.html">Pair Associative Container</A>
</TD>
<TD VAlign=top>
The type of object, <tt>pair<const key_type, data_type></tt>, stored in the hash_multimap.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>hasher</tt>
</TD>
<TD VAlign=top>
<A href="HashedAssociativeContainer.html">Hashed Associative Container</A>
</TD>
<TD VAlign=top>
The <tt>hash_multimap</tt>'s <A href="HashFunction.html">hash function</A>.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>key_equal</tt>
</TD>
<TD VAlign=top>
<A href="HashedAssociativeContainer.html">Hashed Associative Container</A>
</TD>
<TD VAlign=top>
<A href="functors.html">Function object</A> that compares keys for equality.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>pointer</tt>
</TD>
<TD VAlign=top>
<A href="Container.html">Container</A>
</TD>
<TD VAlign=top>
Pointer to <tt>T</tt>.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>reference</tt>
</TD>
<TD VAlign=top>
<A href="Container.html">Container</A>
</TD>
<TD VAlign=top>
Reference to <tt>T</tt>
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>const_reference</tt>
</TD>
<TD VAlign=top>
<A href="Container.html">Container</A>
</TD>
<TD VAlign=top>
Const reference to <tt>T</tt>
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>size_type</tt>
</TD>
<TD VAlign=top>
<A href="Container.html">Container</A>
</TD>
<TD VAlign=top>
An unsigned integral type.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>difference_type</tt>
</TD>
<TD VAlign=top>
<A href="Container.html">Container</A>
</TD>
<TD VAlign=top>
A signed integral type.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>iterator</tt>
</TD>
<TD VAlign=top>
<A href="Container.html">Container</A>
</TD>
<TD VAlign=top>
Iterator used to iterate through a <tt>hash_multimap</tt>. <A href="#1">[1]</A>
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>const_iterator</tt>
</TD>
<TD VAlign=top>
<A href="Container.html">Container</A>
</TD>
<TD VAlign=top>
Const iterator used to iterate through a <tt>hash_multimap</tt>.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>iterator begin()</tt>
</TD>
<TD VAlign=top>
<A href="Container.html">Container</A>
</TD>
<TD VAlign=top>
Returns an <tt>iterator</tt> pointing to the beginning of the <tt>hash_multimap</tt>.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>iterator end()</tt>
</TD>
<TD VAlign=top>
<A href="Container.html">Container</A>
</TD>
<TD VAlign=top>
Returns an <tt>iterator</tt> pointing to the end of the <tt>hash_multimap</tt>.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>const_iterator begin() const</tt>
</TD>
<TD VAlign=top>
<A href="Container.html">Container</A>
</TD>
<TD VAlign=top>
Returns an <tt>const_iterator</tt> pointing to the beginning of the <tt>hash_multimap</tt>.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>const_iterator end() const</tt>
</TD>
<TD VAlign=top>
<A href="Container.html">Container</A>
</TD>
<TD VAlign=top>
Returns an <tt>const_iterator</tt> pointing to the end of the <tt>hash_multimap</tt>.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>size_type size() const</tt>
</TD>
<TD VAlign=top>
<A href="Container.html">Container</A>
</TD>
<TD VAlign=top>
Returns the size of the <tt>hash_multimap</tt>.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>size_type max_size() const</tt>
</TD>
<TD VAlign=top>
<A href="Container.html">Container</A>
</TD>
<TD VAlign=top>
Returns the largest possible size of the <tt>hash_multimap</tt>.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>bool empty() const</tt>
</TD>
<TD VAlign=top>
<A href="Container.html">Container</A>
</TD>
<TD VAlign=top>
<tt>true</tt> if the <tt>hash_multimap</tt>'s size is <tt>0</tt>.
</TD>
</TR>
<TR>
<TD VAlign=top>
<tt>size_type bucket_count() const</tt>
</TD>
<TD VAlign=top>
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