RWTPtrHashSet< T, H, EQ, A > Class Template Reference
[STL Extension-based Collections]

A hash-based container for pointer types. More...

#include <rw/tphset.h>

Inherits RW_SPHAssoc< rw_hashset< T *, rw_deref_hash< H, T >, rw_deref_compare< EQ, T >,A >, RWTPtrHashSet< T, H, EQ,A >, T >.

List of all members.

Public Types
typedef rw_deref_compare< EQ, T >	container_eq
typedef rw_deref_hash< H, T >	container_hash
typedef rw_hashset< T *, container_hash, container_eq,A >	container_type
typedef container_type::size_type	size_type
typedef container_type::difference_type	difference_type
typedef base_type::iterator	iterator
typedef base_type::const_iterator	const_iterator
typedef base_type::value_type	value_type
typedef base_type::reference	reference
typedef base_type::const_reference	const_reference
Public Member Functions
container_type &	std ()
const container_type &	std () const
iterator	begin ()
const_iterator	begin () const
bool	isEmpty () const
iterator	end ()
const_iterator	end () const
size_type	entries () const
void	clear ()
void	clearAndDestroy ()
bool	contains (bool(*fn)(const_value, void *), void *d) const
bool	contains (const_value a) const
const_value	find (bool(*fn)(const_value, void *), void *d) const
value_type	find (const_value key)
const_value	find (const_value a) const
size_type	occurrencesOf (bool(*fn)(const_value, void *), void *d) const
size_type	occurrencesOf (const_value a)
value_type	remove (bool(*fn)(const_value, void *), void *d)
value_type	remove (const_value a)
size_type	removeAll (bool(*fn)(const_value, void *), void *d)
size_type	removeAll (const_value a)
bool	isSubsetOf (const RWTPtrHashSet< T, H, EQ, A > &s) const
bool	isProperSubsetOf (const RWTPtrHashSet< T, H, EQ, A > &s) const
bool	isEquivalent (const RWTPtrHashSet< T, H, EQ, A > &s) const
void	apply (void(*fn)(const T &, void *), void *d) const
void	apply (void(*fn)(const T *, void *), void *d) const
RWTPtrHashSet< T, H, EQ,A > &	Union (const RWTPtrHashSet< T, H, EQ, A > &s)
RWTPtrHashSet< T, H, EQ,A > &	intersection (const RWTPtrHashSet< T, H, EQ, A > &s)
RWTPtrHashSet< T, H, EQ,A > &	difference (const RWTPtrHashSet< T, H, EQ, A > &s)
RWTPtrHashSet< T, H, EQ,A > &	symmetricDifference (const RWTPtrHashSet< T, H, EQ, A > &s)
bool	operator== (const RWTPtrHashSet< T, H, EQ, A > &s) const
bool	operator!= (const RWTPtrHashSet< T, H, EQ, A > &s) const
bool	insert (value_type a)
size_type	capacity () const
float	fillRatio () const
void	resize (size_type sz)
void	swap (RWTPtrHashSet< T, H, EQ, A > &other)
RWTPtrHashSet< T, H, EQ,A > &	operator= (const RWTPtrHashSet< T, H, EQ, A > &s)
RWTPtrHashSet< T, H, EQ,A > &	operator= (RWTPtrHashSet< T, H, EQ, A > &&rhs)
	RWTPtrHashSet (size_type sz=1024, const H &h=H(), const EQ &eq=EQ())
	RWTPtrHashSet (const RWTPtrHashSet< T, H, EQ, A > &rws)
	RWTPtrHashSet (RWTPtrHashSet< T, H, EQ, A > &&rws)
	RWTPtrHashSet (const container_type &s)
	RWTPtrHashSet (T *const *first, T *const *last, size_type sz=1024, const H &h=H(), const EQ &eq=EQ())
	RWTPtrHashSet (const H &h, size_type sz=64)
Related Functions
(Note that these are not member functions.)
template<class T , class H , class EQ , class A >
RWvostream &	operator<< (RWvostream &strm, const RWTPtrHashSet< T, H, EQ, A > &coll)
template<class T , class H , class EQ , class A >
RWFile &	operator<< (RWFile &strm, const RWTPtrHashSet< T, H, EQ, A > &coll)
template<class T , class H , class EQ , class A >
RWvistream &	operator>> (RWvistream &strm, RWTPtrHashSet< T, H, EQ, A > &coll)
template<class T , class H , class EQ , class A >
RWFile &	operator>> (RWFile &strm, RWTPtrHashSet< T, H, EQ, A > &coll)
template<class T , class H , class EQ , class A >
RWvistream &	operator>> (RWvistream &strm, RWTPtrHashSet< T, H, EQ, A > *&p)
template<class T , class H , class EQ , class A >
RWFile &	operator>> (RWFile &strm, RWTPtrHashSet< T, H, EQ, A > *&p)

---

Detailed Description

template<class T, class H, class EQ, class A = std:: allocator < T* >>
class RWTPtrHashSet< T, H, EQ, A >

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. Class A is an allocator of objects of class T. For more information about using custom allocators, please see the Essential Tools Module User's Guide.

H must provide a const hash function on elements of type T via 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.

Note:

Any two keys that are equivalent must hash to the same value.

RWTPtrHashSet<T,H,EQ,A> will not accept an item that is equivalent to an item already in the collection. (RWTPtrHashMultiSet<T,H,EQ,A> may contain multiple items that are equivalent to each other.) Equality is based on the equality object and not on the == operator.

The value type must have operator==() defined. This requirement is imposed by the C++ Standard Library.

Synopsis

 #include <rw/tphset.h>
 RWTPtrHashSet<T,H,EQ,A>   s;

Related Classes

Class RWTPtrHashMultiSet<T,H,EQ,A> offers the same interface to a pointer-based collection that accepts multiple items that compare equal to each other.

Class rw_hashset<T*,rw_deref_hash<H,T>,rw_deref_compare<EQ,T>,A> is the C++ Standard Library collection that serves as the underlying implementation for RWTPtrHashSet<T,H,EQ,A>.

Persistence

Isomorphic

Examples

 #include <iostream>
 #include <functional>

 #include <rw/tphset.h>
 #include <rw/cstring.h>

 struct simple_hash
 {
     unsigned long 
     operator()(const RWCString& ref) const { 
         size_t n = ref.length ();
         return (unsigned long)(n ? n * size_t (ref [0]) : 0);
     }
 };

 void printit (const RWCString* s, void*)
 {
     std::cout << *s << " ";
 }

 int main()
 { 
     RWTPtrHashSet<RWCString,simple_hash, std::equal_to <RWCString> > myset;
     RWCString s;

     myset.insert(new RWCString("one"));
     myset.insert(new RWCString("two"));
     myset.insert(new RWCString("three"));

     RWCString* entry = new RWCString("one");
     if (!myset.insert(entry)) // Rejected: duplicate entry
     {
       delete entry;
     }

     std::cout << "There are " << myset.entries()
               << " items in the hash set and they are: \n"; // Prints "3"


     myset.apply(printit, NULL);

     std::cout << std::endl;

     myset.clearAndDestroy();

     return 0;
 }

Program output:

 There are 3 items in the hash set and they are:
 one two three

---

Member Typedef Documentation

template<class T, class H, class EQ, class A = std:: allocator < T* >>

typedef base_type::const_iterator RWTPtrHashSet< T, H, EQ, A >::const_iterator

Typedef for the const iterator.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

typedef base_type::const_reference RWTPtrHashSet< T, H, EQ, A >::const_reference

Typedef for a const reference to a value in this container.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

typedef rw_deref_compare<EQ,T> RWTPtrHashSet< T, H, EQ, A >::container_eq

Typedef for the equality object.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

typedef rw_deref_hash<H,T> RWTPtrHashSet< T, H, EQ, A >::container_hash

Typedef for the hashing object.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

typedef rw_hashset<T*,container_hash, container_eq ,A > RWTPtrHashSet< T, H, EQ, A >::container_type

Typedef for the C++ Standard Library collection that serves as the underlying implementation for this class.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

typedef container_type::difference_type RWTPtrHashSet< T, H, EQ, A >::difference_type

Typedef for the type of difference between iterators.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

typedef base_type::iterator RWTPtrHashSet< T, H, EQ, A >::iterator

Typedef for the non-const iterator.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

typedef base_type::reference RWTPtrHashSet< T, H, EQ, A >::reference

Typedef for a non-const reference to a value in this container.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

typedef container_type::size_type RWTPtrHashSet< T, H, EQ, A >::size_type

Typedef for the type used to index into this container.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

typedef base_type::value_type RWTPtrHashSet< T, H, EQ, A >::value_type

Typedef for the type of elements in this container.

---

Constructor & Destructor Documentation

template<class T, class H, class EQ, class A = std:: allocator < T* >>

RWTPtrHashSet< T, H, EQ, A >::RWTPtrHashSet	(	size_type	sz = 1024,
		const H &	h = H(),
		const EQ &	eq = EQ()
	)			[inline]

Constructs an empty hashed set. The underlying hash table representation will have sz buckets, will use h for its hashing function, and will use eq to determine equality between elements.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

RWTPtrHashSet< T, H, EQ, A >::RWTPtrHashSet

(

const RWTPtrHashSet< T, H, EQ, A > &

rws

)

[inline]

Copy constructor.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

RWTPtrHashSet< T, H, EQ, A >::RWTPtrHashSet

(

RWTPtrHashSet< T, H, EQ, A > &&

rws

)

[inline]

Move constructor. The constructed list takes ownership of the data owned by rws.

Condition:

This method is only available on platforms with rvalue reference support.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

RWTPtrHashSet< T, H, EQ, A >::RWTPtrHashSet

(

const container_type &

s

)

[inline]

Constructs a pointer-based hash set by copying all elements from s.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

RWTPtrHashSet< T, H, EQ, A >::RWTPtrHashSet	(	T *const *	first,
		T *const *	last,
		size_type	sz = 1024,
		const H &	h = H(),
		const EQ &	eq = EQ()
	)			[inline]

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 underlying hash table representation will have sz buckets, will use h for its hashing function, and will use eq to determine equality between elements.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

RWTPtrHashSet< T, H, EQ, A >::RWTPtrHashSet	(	const H &	h,
		size_type	sz = 64
	)			[inline]

Creates an empty hashed set which uses the hash object h and has an initial hash table capacity of sz.

---

Member Function Documentation

template<class T, class H, class EQ, class A = std:: allocator < T* >>

void RWTPtrHashSet< T, H, EQ, A >::apply	(	void(*)(const T *, void *)	fn,
		void *	d
	)			const [inline]

Applies the user-defined function pointed to by fn to every association in the collection. Client data may be passed through parameter d.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

void RWTPtrHashSet< T, H, EQ, A >::apply	(	void(*)(const T &, void *)	fn,
		void *	d
	)			const [inline]

Applies the user-defined function pointed to by fn to every association in the collection. Client data may be passed through parameter d.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

const_iterator RWTPtrHashSet< T, H, EQ, A >::begin

(

)

const [inline]

Returns an iterator positioned at the first element of self.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

iterator RWTPtrHashSet< T, H, EQ, A >::begin

(

)

[inline]

Returns an iterator positioned at the first element of self.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

size_type RWTPtrHashSet< T, H, EQ, A >::capacity

(

)

const [inline]

Returns the number of buckets (slots) available in the underlying hash representation. See resize().

template<class T, class H, class EQ, class A = std:: allocator < T* >>

void RWTPtrHashSet< T, H, EQ, A >::clear

(

void

)

[inline]

Clears the collection by removing all items from self.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

void RWTPtrHashSet< T, H, EQ, A >::clearAndDestroy

(

void

)

[inline]

Removes all items from the collection and uses operator delete to destroy the objects pointed to by those items. Do not use this method if multiple pointers to the same object are stored. (If the equality operator is reflexive, the container cannot hold such multiple pointers.)

template<class T, class H, class EQ, class A = std:: allocator < T* >>

bool RWTPtrHashSet< T, H, EQ, A >::contains

(

const_value

a

)

const [inline]

Returns true if there exists an element t in self such that the expression (*t == *a) is true, otherwise returns false.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

bool RWTPtrHashSet< T, H, EQ, A >::contains	(	bool(*)(const_value, void *)	fn,
		void *	d
	)			const [inline]

Returns true if there exists an element t in self such that the expression ((*fn)(t,d)) is true, otherwise returns false. Client data may be passed through parameter d.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

RWTPtrHashSet<T,H,EQ ,A >& RWTPtrHashSet< T, H, EQ, A >::difference

(

const RWTPtrHashSet< T, H, EQ, A > &

s

)

[inline]

Sets self to the set-theoretic difference given by (self - s). Elements from each set are dereferenced before being compared.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

const_iterator RWTPtrHashSet< T, H, EQ, A >::end

(

)

const [inline]

Returns an iterator positioned "just past" the last element in self.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

iterator RWTPtrHashSet< T, H, EQ, A >::end

(

)

[inline]

Returns an iterator positioned "just past" the last element in self.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

size_type RWTPtrHashSet< T, H, EQ, A >::entries

(

void

)

const [inline]

Returns the number of items in self.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

float RWTPtrHashSet< T, H, EQ, A >::fillRatio

(

)

const [inline]

Returns the ratio entries() / capacity().

template<class T, class H, class EQ, class A = std:: allocator < T* >>

const_value RWTPtrHashSet< T, H, EQ, A >::find

(

const_value

a

)

const [inline]

If there exists an element t in self such that *a compares equal to *a, returns t. Otherwise, returns rwnil.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

value_type RWTPtrHashSet< T, H, EQ, A >::find

(

const_value

key

)

[inline]

If there exists an element t in self such that *a compares equal to *a, returns t. Otherwise, returns rwnil.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

const_value RWTPtrHashSet< T, H, EQ, A >::find	(	bool(*)(const_value, void *)	fn,
		void *	d
	)			const [inline]

If there exists an element t in self such that the expression ((*fn)(t,d)) is true, returns t. Otherwise, returns rwnil. Client data may be passed through parameter d.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

bool RWTPtrHashSet< T, H, EQ, A >::insert

(

value_type

a

)

[inline]

Adds the item a to the collection. Returns true if the insertion is successful, otherwise returns false. Insertion will fail if the collection already holds an element with an equivalent key.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

RWTPtrHashSet<T,H,EQ ,A >& RWTPtrHashSet< T, H, EQ, A >::intersection

(

const RWTPtrHashSet< T, H, EQ, A > &

s

)

[inline]

Destructively performs a set theoretic intersection of self and s, replacing the contents of self with the result.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

bool RWTPtrHashSet< T, H, EQ, A >::isEmpty

(

)

const [inline]

Returns true if there are no items in the collection, otherwise false.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

bool RWTPtrHashSet< T, H, EQ, A >::isEquivalent

(

const RWTPtrHashSet< T, H, EQ, A > &

s

)

const [inline]

Returns true if there is set equivalence between self and s, otherwise returns false.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

bool RWTPtrHashSet< T, H, EQ, A >::isProperSubsetOf

(

const RWTPtrHashSet< T, H, EQ, A > &

s

)

const [inline]

Returns true if self is a proper subset of s, otherwise false.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

bool RWTPtrHashSet< T, H, EQ, A >::isSubsetOf

(

const RWTPtrHashSet< T, H, EQ, A > &

s

)

const [inline]

Returns true if self is a subset of s or if self is set equivalent to s, otherwise false.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

size_type RWTPtrHashSet< T, H, EQ, A >::occurrencesOf

(

const_value

a

)

[inline]

Returns the number of elements t that compare equal to *a

template<class T, class H, class EQ, class A = std:: allocator < T* >>

size_type RWTPtrHashSet< T, H, EQ, A >::occurrencesOf	(	bool(*)(const_value, void *)	fn,
		void *	d
	)			const [inline]

Returns the number of elements t in self such that the expression ((*fn)(t,d)) is true. Client data may be passed through parameter d.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

bool RWTPtrHashSet< T, H, EQ, A >::operator!=

(

const RWTPtrHashSet< T, H, EQ, A > &

s

)

const [inline]

Returns the negation of operator==().

template<class T, class H, class EQ, class A = std:: allocator < T* >>

RWTPtrHashSet<T,H,EQ ,A >& RWTPtrHashSet< T, H, EQ, A >::operator=

(

RWTPtrHashSet< T, H, EQ, A > &&

rhs

)

[inline]

Move assignment. Self takes ownership of the data owned by rhs.

Condition:

This method is only available on platforms with rvalue reference support.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

RWTPtrHashSet<T,H,EQ ,A >& RWTPtrHashSet< T, H, EQ, A >::operator=

(

const RWTPtrHashSet< T, H, EQ, A > &

s

)

[inline]

Clears all elements of self and replaces them by copying all elements of s.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

bool RWTPtrHashSet< T, H, EQ, A >::operator==

(

const RWTPtrHashSet< T, H, EQ, A > &

s

)

const [inline]

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. Elements are dereferenced before being compared.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

value_type RWTPtrHashSet< T, H, EQ, A >::remove

(

const_value

a

)

[inline]

Removes and returns the first element t in self that compares equal to *a. Returns rwnil if there is no such element.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

value_type RWTPtrHashSet< T, H, EQ, A >::remove	(	bool(*)(const_value, void *)	fn,
		void *	d
	)			[inline]

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. Client data may be passed through parameter d.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

size_type RWTPtrHashSet< T, H, EQ, A >::removeAll

(

const_value

a

)

[inline]

Removes all elements t in self that compare equal to *a a. Returns the number of items removed.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

size_type RWTPtrHashSet< T, H, EQ, A >::removeAll	(	bool(*)(const_value, void *)	fn,
		void *	d
	)			[inline]

Removes all elements t in self such that the expression ((*fn)(t,d)) is true. Returns the number of items removed. Client data may be passed through parameter d.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

void RWTPtrHashSet< T, H, EQ, A >::resize

(

size_type

sz

)

[inline]

Changes the capacity of self by creating a new hashed set with a capacity of sz. This function 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.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

const container_type& RWTPtrHashSet< T, H, EQ, A >::std

(

)

const [inline]

Returns a reference to the underlying C++ Standard Library collection that serves as the implementation for self.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

container_type& RWTPtrHashSet< T, H, EQ, A >::std

(

)

[inline]

Returns a reference to the underlying C++ Standard Library collection that serves as the implementation for self.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

void RWTPtrHashSet< T, H, EQ, A >::swap

(

RWTPtrHashSet< T, H, EQ, A > &

other

)

[inline]

Swaps the data held by self with the data held by other, including the T and EQ objects. This method does not copy or destroy any of the items swapped; rather, it swaps the underlying hash tables.

template<class T, class H, class EQ, class A = std:: allocator < T* >>

RWTPtrHashSet<T,H,EQ ,A >& RWTPtrHashSet< T, H, EQ, A >::symmetricDifference

(

const RWTPtrHashSet< T, H, EQ, A > &

s

)

[inline]

Destructively performs a set theoretic symmetric difference operation on self and s. Self is replaced by the result. A symmetric difference can be defined as .

template<class T, class H, class EQ, class A = std:: allocator < T* >>

RWTPtrHashSet<T,H,EQ ,A >& RWTPtrHashSet< T, H, EQ, A >::Union

(

const RWTPtrHashSet< T, H, EQ, A > &

s

)

[inline]

Destructively performs a set theoretic union operation on self and s. Self is replaced by the result.

Note:

The uppercase "U" in Union avoids conflict with the C++ reserved word.

---

Friends And Related Function Documentation

template<class T , class H , class EQ , class A >

RWFile & operator<<	(	RWFile &	strm,
		const RWTPtrHashSet< T, H, EQ, A > &	coll
	)			[related]

Saves the collection coll onto the RWFile strm, or a reference to it if it has already been saved.

template<class T , class H , class EQ , class A >

RWvostream & operator<<	(	RWvostream &	strm,
		const RWTPtrHashSet< T, H, EQ, A > &	coll
	)			[related]

Saves the collection coll onto the output stream strm, or a reference to it if it has already been saved.

template<class T , class H , class EQ , class A >

RWFile & operator>>	(	RWFile &	strm,
		RWTPtrHashSet< T, H, EQ, A > *&	p
	)			[related]

Looks at the next object on the RWFile 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 the application is responsible for deleting it.

template<class T , class H , class EQ , class A >

RWvistream & operator>>	(	RWvistream &	strm,
		RWTPtrHashSet< T, H, EQ, A > *&	p
	)			[related]

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 the application is responsible for deleting it.

template<class T , class H , class EQ , class A >

RWFile & operator>>	(	RWFile &	strm,
		RWTPtrHashSet< T, H, EQ, A > &	coll
	)			[related]

Restores the contents of the collection coll from the RWFile strm.

template<class T , class H , class EQ , class A >

RWvistream & operator>>	(	RWvistream &	strm,
		RWTPtrHashSet< T, H, EQ, A > &	coll
	)			[related]

Restores the contents of the collection coll from the input stream strm.