RWTValHashMultiSet(3C++) RWTValHashMultiSet(3C++)
Name
RWTValHashMultiSet<T,H,EQ> - Rogue Wave library class
Synopsis
#include <rw/tvhasht.h>
RWTValHashMultiSet<T,H,EQ>
Please Note!
If you have the Standard C++ Library, use the interface described here.
Otherwise, use the interface for RWTValHashTable described in Appendix A.
Description
This class maintains a collection of values, which are stored according
to a hash object of type H. H must offer a hash function for elements of
type T via a public member
unsigned long operator()(const T& x) const 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) const which should return true
if x and y are equivalent, false otherwise. RWTValHashMultiSet<T,H,EQ>
may contain multiple items that compare equal to each other.
(RWTValHashSet<T,H,EQ> will not accept an item that compares equal to an
item already in the collection.)
Persistence
Isomorphic
Example
//
// tvhmsstr.cpp
//
#include <rw/tvhasht.h>
#include <rw/cstring.h>
#include <iostream.h>
struct silly_hash{
unsigned long operator()(RWCString x) const
{ return x.length() * (long)x[0]; }
};
main(){
RWTValHashMultiSet<RWCString,silly_hash,equal_to<RWCString> > set1;
RWTValHashMultiSet<RWCString,silly_hash,equal_to<RWCString> > set2;
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set1.insert("one");
set1.insert("two");
set1.insert("three");
set1.insert("one"); // OK: duplicates allowed
set1.insert("one");
cout << set1.entries() << endl; // Prints "5"
set2.insert("one");
set2.insert("five");
set2.insert("one");
cout << ((set1.isEquivalent(set2)) ? "TRUE" : "FALSE") << endl;
// Prints "FALSE"
set2.intersection(set1);
set1.clear();
cout << set1.entries() << endl; // Prints "0"
cout << set2.entries() << endl; // Prints "2"
return 0;
Related Classes
}
Class RWTValHashSet<T,H,EQ> offers the same interface to a collection
that will not accept multiple items that compare equal to each other.
Class rw_hashmultiset<T,H,EQ> is the C++-standard compliant collection
that serves as the underlying implementation for
RWTValHashMultiSet<T,H,EQ>.
Public Typedefs
typedef rw_hashmultiset<T,H,EQ> container_type;
typedef container_type::iterator iterator;
typedef container_type::const_iterator const_iterator;
typedef container_type::size_type size_type;
typedef T value_type;
typedef T& reference;
typedef const T& const_reference;
Public Constructors
RWTValHashMultiSet<T,H,EQ>
(size_type sz = 1024,const H& h = H(),const EQ& eq = EQ());
Constructs an empty set. The underlying hash table representation will
have sz buckets, will use h as its hashing function and will use eq to
determine equivalence between elements.
RWTValHashMultiSet<T,H,EQ>(const rw_hashmultiset<T,H,EQ>& s);
Constructs a set by copying all elements of s.
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RWTValHashMultiSet<T,H,EQ>(const RWTValHashMultiSet<T,H,EQ>&);
Copy constructor.
RWTValHashMultiSet<T,H,EQ>
(const H& h,size_type sz = RWDEFAULT_CAPACITY);
Creates an empty hashed multi-set which uses the hash object h and has an
initial hash table capacity of sz.
RWTValHashMultiSet<T,H,EQ>(const T* first,const T* last,size_type sz = 1024,const H& h = H(),const EQ& eq = EQ());
Constructs a set by copying elements from the array of Ts pointed to by
first, up to, but not including, the element pointed to by last. The
underlying hash table representation will have sz buckets, will use h as
its hashing function and will use eq to determine equivalence between
elements.
Public Member Operators
RWTValHashMultiSet<T,H,EQ>&
operator=(const RWTValHashMultiSet<T,H,EQ>& s);
RWTValHashMultiSet<T,H,EQ>&
operator=(const rw_hashmultiset<T,H,EQ>& s);
Destroys all elements of self and replaces them by copying all elements
of s.
bool
operator==(const RWTValHashMultiSet<T,H,EQ>& s) const;
bool
operator==(const rw_hashmultiset<T,H,EQ>& s) const;
Returns true if self compares equal to s, otherwise returns false. Two
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.
Public Member Functions
void
apply(void (*fn)(const_reference,void*), void* d) const;
Applies the user-defined function pointed to by fn to every item in the
collection. This function must have prototype:
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void yourfun(const_reference 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. Each item will
have its destructor called.
bool
contains(const_reference 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_reference,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:
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bool yourTester(const_reference a, void* d);
Client data may be passed through parameter d.
void
difference(const RWTValHashMultiSet<T,H,EQ>& s);
Sets self to the set-theoretic difference given by (self - s).
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().
bool
find(const_reference a,T& k) const;
If there exists an element t in self such that the expression (t == a) is
true, assigns t to k and returns true. Otherwise, returns false and
leaves the value of k unchanged.
bool
find(bool (*fn)(const_reference,void*),void* d,T& k) const;
If there exists an element t in self that compares equal to a, assigns t
to k and returns true. Otherwise, returns false and leaves the value of
k unchanged. fn points to a user-defined tester function which must have
prototype:
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bool yourTester(const_reference a, void* d);
Client data may be passed through parameter d.
bool
insert(const_reference a);
Adds the item a to the collection. Returns true.
void
intersection(const RWTValHashMultiSet<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 RWTValHashMultiSet<T,H,EQ>& s) const;
Returns true if there is set equivalence between self and s, and returns
false otherwise.
bool
isProperSubsetOf(const RWTValHashMultiSet<T,H,EQ>& s) const;
Returns true if self is a proper subset of s, and returns false
otherwise.
bool
isSubsetOf(const RWTValHashMultiSet<T,H,EQ>& s) const;
Returns true if self is a subset of s, and returns false otherwise.
size_type
occurrencesOf(const_reference a) const;
Returns the number of elements t in self that compares equal to a.
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size_type
occurrencesOf(bool (*fn)(const_reference,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_reference a, void* d);
Client data may be passed through parameter d.
bool
remove(const_reference a);
Removes the first element t in self that compares equal to a and returns
true. Returns false if there is no such element.
bool
remove(bool (*fn)(const_reference,void*), void* d);
Removes the first element t in self such that the expression ((*fn)(t,d))
is true and returns true. Returns false if there is no such element. fn
points to a user-defined tester function which must have prototype:
bool yourTester(const_reference a, void* d);
Client data may be passed through parameter d.
size_type
removeAll(const_reference a);
Removes all elements t in self that compare equal to a. Returns the
number of items removed.
size_type
removeAll(bool (*fn)(const_reference,void*), void* d);
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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_reference 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_hashmultiset<T,H,EQ>&
std();
const rw_hashmultiset<T,H,EQ>&
std() const;
Returns a reference to the underlying C++-standard collection that serves
as the implementation for self. This reference may be used freely,
providing access to the C++-standard interface as well as
interoperability with other software components that make use of the
C++-standard collections.
void
symmetricDifference(const RWTValHashMultiSet<T,H,EQ>& s);
Destructively performs a set theoretic symmetric difference operation on
self and s. Self is replaced by the result. A symmetric difference can
be informally defined as (A_B)-(A_B).
void
Union(const RWTValHashMultiSet<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
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conflict with the C++ reserved word.
Related Global Operators
RWvostream&
operator<<(RWvostream& strm,
const RWTValHashMultiSet<T,H,EQ>& coll);
RWFile&
operator<<(RWFile& strm,
const RWTValHashMultiSet<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, RWTValHashMultiSet<T,H,EQ>& coll);
RWFile&
operator>>(RWFile& strm, RWTValHashMultiSet<T,H,EQ>& coll);
Restores the contents of the collection coll from the input stream strm.
RWvistream&
operator>>(RWvistream& strm, RWTValHashMultiSet<T,H,EQ>*& p);
RWFile&
operator>>(RWFile& strm, RWTValHashMultiSet<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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