RWTPtrSet<T,C,A>

Module:  Essential Tools Module   Group:  STL-based Collection Classes

Does not inherit

• Local Index
• Synopsis
• Description
• Persistence
• Example
• Related Classes
• Public Typedefs
• Public Constructors
• Public Member Operators
• Public Member Functions
• Related Global Operators

Members

apply() begin() clear() clearAndDestroy() const_iterator const_reference container_comp contains() difference()

difference_type end() entries() find() insert() intersection() isEmpty() isEquivalent() isProperSubsetOf()

isSubsetOf() iterator occurrencesOf() operator<() operator=() operator==() reference remove() removeAll()

RWTPtrSet<T,C,A>() size_type std() symmetricDifference() Union() value_type

Non-Members

operator>>()

operator<<()

#include <rw/tpset.h> 
RWTPtrSet<T,C,A> s;

This class maintains a pointer-based collection of values, which are ordered according to a comparison object of type C. Class T is the type pointed to by the items in the collection. C must induce a total ordering on elements of type T via a public member

bool operator()(const T& x, const T& y)

which returns true if x should precede y within the collection. The structure less<T> from the C++-standard header file <functional> is an example. Note that items in the collection will be dereferenced before being compared.

RWTPtrSet<T,C,A> will not accept an item that compares equal to an item already in the collection. (RWTPtrMultiSet<T,C,A> may contain multiple items that compare equal to each other.) Equality is based on the comparison object and not on the == operator. Given a comparison object comp, items a and b are equal if !comp(a,b) && !comp(b,a).

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

Isomorphic

In this example, a pointer-based set of RWCStrings is exercised.

//
// tpset.cpp
//
#include <rw/tpset.h>
#include <rw/cstring.h>
#include <iostream>
#include <functional>

int main(){
  RWTPtrSet<RWCString, std::less<RWCString> > set;

  set.insert(new RWCString("one"));
  set.insert(new RWCString("two"));
  set.insert(new RWCString("three"));
  set.insert(new RWCString("one"));  // Rejected: duplicate entry

  std::cout << set.entries() << std::endl;   // Prints "3"

  set.clearAndDestroy();
  std::cout << set.entries() << std::endl;   // Prints "0"

  return 0;
}

Program output:

3
0

Class RWTPtrMultiSet<T,C,A> offers the same interface to a pointer-based collection that accepts multiple items that compare equal to each other. RWTPtrMap<K,T,C,A> is a pointer-based collection of key-value pairs.

Class std::set<T*,rw_deref_compare<C,T>,A<T*> > is the C++-standard collection that serves as the underlying implementation for RWTPtrSet<T,C,A>.

typedef rw_deref_compare<C,T> container_comp; 
3.3

typedef typename container_type::size_type size_type; 
typedef typename container_type::difference_type
  difference_type; 
typedef typename container_type::iterator iterator; 
typedef typename container_type::const_iterator
  const_iterator; 
typedef T* value_type; 
typedef T*const& reference; 
typedef T*const& const_reference; 

RWTPtrSet<T,C,A>(const container_comp& comp =
     container_comp());

Constructs an empty set.

RWTPtrSet<T,C,A>(const RWTPtrSet<T,C,A>& rws); 

Copy constructor.

RWTPtrSet<T,C,A>(const container_type& s);

Creates a pointer based set by copying all elements from s.

RWTPtrSet<T,C,A>(T* const* first,T* const* last,
  const container_comp& comp = container_comp());

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.

RWTPtrSet<T,C,A>&
operator=(const container_type& s); 
RWTPtrSet<T,C,A>&
operator=(const RWTPtrSet<T,C,A>& s);

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

bool
operator<(const RWTPtrSet<T,C,A>& s); 

Returns true if self compares lexicographically less than s, otherwise returns false. Items in each collection are dereferenced before being compared. Assumes that type T has well-defined less-than semantics.

bool
operator==(const RWTPtrSet<T,C,A>& s); 

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.

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. This 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.

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 this method if multiple pointers to the same object are stored.

bool
contains(const T* a) const; 

Returns true if there exists an element t in self that compares equal with *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 RWTPtrSet<T,C,A>& 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.

T*
find(const T* a);
const T*
find(const T* a) const; 

If there exists an element t in self that compares equal with *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 if the insertion is successful, otherwise returns false. The function will return true unless the collection already holds an element with an equivalent key.

void
intersection(const RWTPtrSet<T,C,A>& s); 

Sets self to the intersection of self and s. Elements from each set are dereferenced before being compared.

bool
isEmpty() const; 

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

bool
isEquivalent(const RWTPtrSet<T,C,A>& s) const; 

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

bool
isProperSubsetOf(const RWTPtrSet<T,C,A>& s) const; 

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

bool
isSubsetOf(const RWTPtrSet<T,C,A>& 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 with *a.

size_type
occurrencesOf(bool (*fn)(T*,void*), void* d);
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 with *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);

Client data may be passed through parameter d.

size_type
removeAll(const T* a); 

Removes all elements t in self that compares equal with *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.

set<T*, container_comp,A<T*> >&
std();
const set<T*, container_comp,A<T*> >&
std() const;

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

void
symmetricDifference(const RWTPtrSet<T,C,A>& s); 

Sets self to the symmetric difference of self and s. Elements from each set are dereferenced before being compared.

void
Union(const RWTPtrSet<T,C,A>& s); 

Sets self to the union of self and s. Elements from each set are dereferenced before being compared. Note the uppercase "U" in Union to avoid conflict with the C++ reserved word.

RWvostream&
operator<<(RWvostream& strm, const RWTPtrSet<T,C,A>& coll); 
RWFile&
operator<<(RWFile& strm, const RWTPtrSet<T,C,A>& 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, RWTPtrSet<T,C,A>& coll); 
RWFile&
operator>>(RWFile& strm, RWTPtrSet<T,C,A>& coll);

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

RWvistream&
operator>>(RWvistream& strm, RWTPtrSet<T,C,A>*& p); 
RWFile&
operator>>(RWFile& strm, RWTPtrSet<T,C,A>*& 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.

© Copyright Rogue Wave Software, Inc. All Rights Reserved.
Rogue Wave and SourcePro are registered trademarks of Rogue Wave Software, Inc. in the United States and other countries. All other trademarks are the property of their respective owners.
Contact Rogue Wave about documentation or support issues.