#include <rw/tpset.h> RWTPtrSet<T,C> s;
RWTPtrSet requires the Standard C++ Library.
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> will not accept an item that compares equal to an item already in the collection. (RWTPtrMultiSet<T,C> 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 Standard C++ 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.h>
#include <function.h>
main(){
RWTPtrSet<RWCString, 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
cout << set.entries() << endl; // Prints "3"
set.clearAndDestroy();
cout << set.entries() << endl; // Prints "0"
return 0;
}
Class RWTPtrMultiSet<T,C> offers the same interface to a pointer-based collection that accepts multiple items that compare equal to each other. RWTPtrMap<K,T,C> is a pointer-based collection of key-value pairs.
Class set<T*,rw_deref_compare<C,T>,allocator> is the C++-standard collection that serves as the underlying implementation for RWTPtrSet<T,C>.
typedef rw_deref_compare<C,T> container_comp; typedef set<T*, container_comp,allocator> 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;
RWTPtrSet<T,C>(const container_comp& comp = container_comp());
Constructs an empty set.
RWTPtrSet<T,C>(const RWTPtrSet<T,C>& rws);
Copy constructor.
RWTPtrSet<T,C>(const container_type& s);
Creates a pointer based set by copying all elements from s.
RWTPtrSet<T,C>(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>& operator=(const container_type& s); RWTPtrSet<T,C>& operator=(const RWTPtrSet<T,C>& s);
Clears all elements of self and replaces them by copying all elements of s.
bool operator<(const RWTPtrSet<T,C>& 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>& 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>& 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.
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>& 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>& s) const;
Returns true if there is set equivalence between self and s, and returns false otherwise.
bool isProperSubsetOf(const RWTPtrSet<T,C>& s) const;
Returns true if self is a proper subset of s, and returns false otherwise.
bool isSubsetOf(const RWTPtrSet<T,C>& 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 par_meter 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,allocator>& std(); const set<T*, container_comp,allocator>& std() const;
Returns a reference to the underlying C++-standard collection that serves as the implementation for self.
void symmetricDifference(const RWTPtrSet<T,C>& 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>& 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>& coll); RWFile& operator<<(RWFile& strm, const RWTPtrSet<T,C>& 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>& coll); RWFile& operator>>(RWFile& strm, RWTPtrSet<T,C>& coll);
Restores the contents of the collection coll from the input stream strm.
RWvistream& operator>>(RWvistream& strm, RWTPtrSet<T,C>*& p); RWFile& operator>>(RWFile& strm, RWTPtrSet<T,C>*& 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.