RWTPtrHashMultiSet(3C++) RWTPtrHashMultiSet(3C++)
Name
RWTPtrHashMultiSet<T,H,EQ> - Rogue Wave library class
Synopsis
#include <rw/tphasht.h>
RWTPtrHashMultiSet<T,H,EQ> hmset;
Please Note!
If you have the Standard C++ Library, use the interface described here.
Otherwise, use the interface for RWTPtrHashTable described in Appendix A.
Description
This class maintains a pointer-based collection of values, which are
stored according to a hash object of type H. Class T is the type pointed
to by the items in the collection. H must provide a hash function on
elements of type T via a public member
unsigned long operator()(const T& x)
Objects within the collection will be grouped together based on an
equality object of type EQ. EQ must ensure this grouping via public
member
bool operator()(const T& x, const T& y)
which should return true if x and y are equivalent, false otherwise.
RWTPtrHashMultiSet<T,H,EQ> may contain multiple items that compare equal
to each other. (RWTPtrHashSet<T,H,EQ> will not accept an item that
compares equal to an item already in the collection.)
Persistence
Isomorphic
Examples
//
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// tphasht.cpp
//
#include <rw/tphasht.h>
#include <rw/cstring.h>
#include <iostream.h>
struct silly_hash{
unsigned long operator()(RWCString x) const
{ return x.length() * (long)x(0); }
};
main(){
RWTPtrHashMultiSet<RWCString,silly_hash,equal_to<RWCString> > set1;
RWTPtrHashMultiSet<RWCString,silly_hash,equal_to<RWCString> > set2;
set1.insert(new RWCString("one"));
set1.insert(new RWCString("two"));
set1.insert(new RWCString("three"));
set1.insert(new RWCString("one")); // OK: duplicates allowd
cout << set1.entries() << endl; // Prints "4"
set2 = set1;
cout << ((set1.isEquivalent(set2)) ? "TRUE" : "FALSE") << endl;
// Prints "TRUE"
set2.difference(set1);
set1.clearAndDestroy();
cout << set1.entries() << endl; // Prints "0"
cout << set2.entries() << endl; // Prints "0"
return 0;
}
Related Classes
Class RWTPtrHashSet<T,H,EQ> offers the same interface to a pointer-based
collection that will not accept multiple items that compare equal to each
other. Class rw_hashmultiset<T*,rw_deref_hash<H,T>,rw_deref_compare<EQ,T>
> is the C++-standard collection that serves as the underlying
implementation for RWTPtrHashMultiSet<T,H,EQ>.
Public Typedefs
typedef rw_deref_compare<EQ,T> container_eq;
typedef rw_deref_hash<H,T> container_hash;
typedef rw_hashmultiset<T*,container_hash,container_eq>
container_type;
typedef container_type::size_type size_type;
typedef container_type::difference_type difference_type;
typedef container_type::iterator iterator;
typedef container_type::const_iterator const_iterator;
typedef T* value_type;
typedef T* const& reference;
typedef T* const& const_reference;
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Public Constructors
RWTPtrHashMultiSet<T,H,EQ>
(size_type sz=1024,const H& h = H(),const EQ& eq = EQ());
Constructs an empty multi set. The hash table representation used by
self multi-set will have sz buckets, use h as a hashing function and eq
to test for equality between stored elements.
RWTPtrHashMultiSet<T,H,EQ>
(const RWTPtrHashMultiSet<T,H,EQ>& rws);
Copy constructor.
RWTPtrHashMultiSet<T,H,EQ>
(const rw_hashmultiset<T*,container_hash, container_eq>& s);
Constructs a hashed multi-set, copying all element from s.
RWTPtrHashMultiSet<T,H,EQ>
(const H& h,size_type sz = RWDEFAULT_CAPACITY);
This Tools.h++ 6.xstyle constructor creates an empty hashed multi-set
which uses the hash object h and has an initial hash table capacity of
sz.
RWTPtrHashMultiSet<T,H,EQ>(T*const* first,T*const* last,
size_type sz=1024,const H& h = H(),const EQ& eq = EQ());
Constructs a set by copying elements from the array of T*s pointed to by
first, up to, but not including, the element pointed to by last. The
hash table representation used by self multi-set will have sz buckets,
use h as a hashing function and eq to test for equality between stored
elements.
Public Member Operators
RWTPtrHashMultiSet<T,H,EQ>&
operator=(const RWTPtrHashMultiSet<T,H,EQ>& s);
Clears all elements of self and replaces them by copying all elements of
s.
bool
operator==(const RWTPtrHashMultiSet<T,H,EQ>& s) const;
Returns true if self compares equal to s, otherwise returns false. Two
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collections are equal if both have the same number of entries, and
iterating through both collections produces, in turn, individual elements
that compare equal to each other. Elements are dereferenced before being
compared.
Public Member Functions
void
apply(void (*fn)(const T*,void*), void* d) const;
Applies the user-defined function pointed to by fn to every item in the
collection. self function must have prototype:
void yourfun(const T* a, void* d);
Client data may be passed through parameter d.
iterator
begin();
const_iterator
begin() const;
Returns an iterator positioned at the first element of self.
size_type
capacity() const;
Returns the number of buckets(slots) available in the underlying hash
representation. See resize below.
void
clear();
Clears the collection by removing all items from self.
void
clearAndDestroy();
Removes all items from the collection and uses operator delete to destroy
the objects pointed to by those items. Do not use self method if
multiple pointers to the same object are stored.
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bool
contains(const T* a) const;
Returns true if there exists an element t in self that compares equal to
*a, otherwise returns false.
bool
contains(bool (*fn)(const T*,void*), void* d) const;
Returns true if there exists an element t in self such that the
expression ((*fn)(t,d)) is true, otherwise returns false. fn points to a
user-defined tester function which must have prototype:
bool yourTester(const T* a, void* d);
Client data may be passed through parameter d.
void
difference(const RWTPtrHashMultiSet<T,H,EQ>& s);
Sets self to the set-theoretic difference given by (self - s). Elements
from each set are dereferenced before being compared.
iterator
end();
const_iterator
end() const;
Returns an iterator positioned "just past" the last element in self.
size_type
entries() const;
Returns the number of items in self.
float
fillRatio() const;
Returns the ratio entries()/capacity().
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const T*
find(const T* a) const;
If there exists an element t in self that compares equal to *a, returns
t. Otherwise, returns rwnil.
const T*
find(bool (*fn)(const T*,void*), void* d) const;
If there exists an element t in self such that the expression
((*fn)(t,d)) is true, returns t. Otherwise, returns rwnil. fn points to
a user-defined tester function which must have prototype:
bool yourTester(const T* a, void* d);
Client data may be passed through parameter d.
bool
insert(T* a);
Adds the item a to the collection. Returns true.
void
intersection(const RWTPtrHashMultiSet<T,H,EQ>& s);
Destructively performs a set theoretic intersection of self and s,
replacing the contents of self with the result.
bool
isEmpty() const;
Returns true if there are no items in the collection, false otherwise.
bool
isEquivalent(const RWTPtrHashMultiSet<T,H,EQ>& s) const;
Returns true if there is set equivalence between self and s; returns
false otherwise.
bool
isProperSubsetOf(const RWTPtrHashMultiSet<T,H,EQ>& s) const;
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Returns true if self is a proper subset of s; returns false otherwise.
bool
isSubsetOf(const RWTPtrHashMultiSet<T,H,EQ>& s) const;
Returns true if self is a subset of s or if self is set equivalent to s,
false otherwise.
size_type
occurrencesOf(const T* a) const;
Returns the number of elements t in self that compare equal to *a.
size_type
occurrencesOf(bool (*fn)(const T*,void*), void* d) const;
Returns the number of elements t in self such that the
expression((*fn)(t,d)) is true. fn points to a user-defined tester
function which must have prototype:
bool yourTester(const T* a, void* d);
Client data may be passed through parameter d.
T*
remove(const T* a);
Removes and returns the first element t in self that compares equal to
*a. Returns rwnil if there is no such element.
T*
remove(bool (*fn)(const T*,void*), void* d);
Removes and returns the first element t in self such that the expression
((*fn)(t,d)) is true. Returns rwnil if there is no such element. fn
points to a user-defined tester function which must have prototype:
bool yourTester(const T* a, void* d);
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Client data may be passed through parameter d.
size_type
removeAll(const T* a);
Removes all elements t in self that compare equal to *a. Returns the
number of items removed.
size_type
removeAll(bool (*fn)(const T*,void*), void* d);
Removes all elements t in self such that the expression ((*fn)(t,d))is
true. Returns the number of items removed. fn points to a user-defined
tester function which must have prototype:
bool yourTester(const T* a, void* d);
Client data may be passed through parameter d.
void
resize(size_type sz);
Changes the capacity of self by creating a new hashed multi-set with a
capacity of sz . resize copies every element of self into the new
container and finally swaps the internal representation of the new
container with the internal representation of self.
rw_hashset<T*,container_hash,container_eq>&
std();
const rw_hashset<T*,container_hash,container_eq>&
std() const;
Returns a reference to the underlying C++-standard collection that serves
as the implementation for self.
void
symmetricDifference(const RWTPtrHashMultiSet<T,H,EQ>& rhs);
Destructively performs a set theoretic symmetric difference operation on
self and rhs. Self is replaced by the result. A symmetric difference can
be informally defined as (A_B)-(A_B).
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void
Union(const RWTPtrHashMultiSet<T,H,EQ>& rhs);
Destructively performs a set theoretic union operation on self and rhs.
Self is replaced by the result. Note the uppercase "U" in Union to avoid
conflict with the C++ reserved word.
Related Global Operators
RWvostream&
operator<<(RWvostream& strm,
const RWTPtrHashMultiSet<T,H,EQ>& coll);
RWFile&
operator<<(RWFile& strm,
const RWTPtrHashMultiSet<T,H,EQ>& coll);
Saves the collection coll onto the output stream strm, or a reference to
it if it has already been saved.
RWvistream&
operator>>(RWvistream& strm,
RWTPtrHashMultiSet<T,H,EQ>& coll);
RWFile&
operator>>(RWFile& strm,
RWTPtrHashMultiSet<T,H,EQ>& coll);
Restores the contents of the collection coll from the input stream strm.
RWvistream&
operator>>(RWvistream& strm,
RWTPtrHashMultiSet<T,H,EQ>*& p);
RWFile&
operator>>(RWFile& strm,
RWTPtrHashMultiSet<T,H,EQ>*& p);
Looks at the next object on the input stream strm and either creates a
new collection off the heap and sets p to point to it, or sets p to point
to a previously read instance. If a collection is created off the heap,
then you are responsible for deleting it.
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