RWTValMap(3C++) RWTValMap(3C++)
Name
RWTValMap<K,T,C> - Rogue Wave library class
Synopsis
#include <rw/tvmap.h>
RWTValMap<K,T,C> m;
Standard C++ Library Dependent!RWTValMap requires the Standard C++ Library.
Description
This class maintains a collection of keys, each with an associated item
of type T. Order is determined by the key according to a comparison
object of type C. C must induce a total ordering on elements of type K
via a public member
bool operator()(const K& x, const K& y) const which returns true if x
and its partner should precede y and its partner within the collection.
The structure less<T> from the C++-standard header file <functional> is
an example. RWTValMap<K,T,C> will not accept a key that compares equal
to any key already in the collection. (RWTValMultiMap<K,T,C> may contain
multiple keys that compare equal to each other.) Equality is based on
the comparison object and not on the == operator. Given a comparison
object comp, keys a and b are equal if
!comp(a,b) && !comp(b,a).
Persistence
Isomorphic.
Examples
In this example, a map of RWCStrings and RWDates is exercised.
//
// tvmbday.cpp
//
#include <rw/tvmap.h>
#include <rw/cstring.h>
#include <rw/rwdate.h>
#include <iostream.h>
main(){
RWTValMap<RWCString, RWDate, less<RWCString> > birthdays;
birthdays.insert("John", RWDate(12, "April",1975));
birthdays.insert("Ivan", RWDate(2, "Nov", 1980));
// Alternative syntax:
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birthdays["Susan"] = RWDate(30, "June", 1955);
birthdays["Gene"] = RWDate(5, "Jan", 1981);
// Print a birthday:
cout << birthdays["John"] << endl;
return 0;
}
Program Output:
Related Classes
04/12/75
Class RWTValMultiMap<K,T,C> offers the same interface to a collection
that accepts multiple keys that compare equal to each other.
RWTValSet<T,C> maintains a collection of keys without the associated
values. Class map<K,T,C,allocator> is the C++-standard collection that
serves as the underlying implementation for this collection.
Public Typedefs
typedef map<K,T,C,allocator> container_type;
typedef container_type::iterator iterator;
typedef container_type::const_iterator const_iterator;
typedef container_type::size_type size_type;
typedef pair <const K,T> value_type;
typedef pair <const K,T>& reference;
typedef const pair <const K,T>& const_reference;
Public Constructors
RWTValMap<K,T,C>(const C& comp = C());
Constructs an empty map with comparator comp.
RWTValMap<K,T,C>(const container_type& m);
Constructs a map by copying all elements of m.
RWTValMap<K,T,C>(const RWTValMap<K,T,C>& rwm);
Copy constructor.
RWTValMap<K,T,C>(const value_type* first,
const value_type* last,const C& comp = C());
Constructs a map by copying elements from the array of value_type pairs
pointed to by first, up to, but not including, the pair pointed to by
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last.
Public Member Operators
RWTValMap<K,T,C>&
operator=(const RWTValMap<K,T,C>& m);
RWTValMap<K,T,C>&
operator=(const container_type& m);
Destroys all elements of self and replaces them by copying all
associations from m.
bool
operator<(const RWTValMap<K,T,C>& m) const;
bool
operator<(const container_type & m) const;
Returns true if self compares lexicographically less than m, otherwise
returns false. Assumes that type K has well-defined less-than semantics
(T::operator<(const K&) or equivalent).
bool
operator==(const RWTValMap<K,T,C>& m) const;
bool
operator==(const container_type & m) const;
Returns true if self compares equal to m, otherwise returns false. Two
collections are equal if both have the same number of entries, and
iterating through both collections produces, in turn, individual pairs
that compare equal to each other.
T&
operator[](const K& key);
Looks up key and returns a reference to its associated item. If the key
is not in the dictionary, then it will be added with an associated item
provided by the default constructor for type T.
Public Member Functions
void
apply(void (*fn)(const K&, T&, void*),void* d);
void
apply(void (*fn)(const K&, const T&, void*), void* d) const;
Applies the user-defined function pointed to by fn to every association
in the collection. This function must have one of the prototypes: void
yourfun(const K& key, T& a, void* d);
void yourfun(const K& key, const T& a,void* d); Client data may be
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passed through parameter d.
void
applyToKeyAndValue(void (*fn)(const K&, T&, void*),void* d);
void
applyToKeyAndValue
(void (*fn)(const K&, const T&, void*), void* d) const;
This is a deprecated version of the apply member above. It behaves
exactly the same as apply.
iterator
begin();
const_iterator
begin() const;
Returns an iterator positioned at the first pair in self.
void
clear();
Clears the collection by removing all items from self. Each key and its
associated item will have its destructor called.
bool
contains(const K& key) const;
Returns true if there exists a key j in self that compares equal to key,
otherwise returns false.
bool
contains(bool (*fn)(const_reference,void*), void* d) const;
Returns true if there exists an association a in self such that the
expression ((*fn)(a,d)) is true, otherwise returns false. 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.
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iterator
end();
const_iterator
end() const;
Returns an iterator positioned "just past" the last association in self.
size_type
entries() const;
Returns the number of associations in self.
bool
find(const K& key, Key& r) const;
If there exists a key j in self that compares equal to key, assigns j to
r and returns true. Otherwise, returns false and leaves the value of r
unchanged.
bool
find(bool (*fn)(const_reference,void*), void* d,
pair<K,T>& r) const;
If there exists an association a in self such that the expression
((*fn)(a,d)) is true, assigns a to r 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:
bool yourTester(const_reference a, void* d);
Client data may be passed through parameter d.
bool
findValue(const K& key, T& r) const;
If there exists a key j in self that compares equal to key, assigns the
item associated with j to r and returns true. Otherwise, returns false
and leaves the value of r unchanged.
bool
findKeyValue(const K& key, K& kr, T& tr) const;
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If there exists a key j in self that compares equal to key, assigns j to
kr, assigns the item associated with j to tr, and returns true.
Otherwise, returns false and leaves the values of kr and tr unchanged.
bool
insert(const K& key, const T& a);
Adds key with associated 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 association with the
equivalent key.
bool
insertKeyAndValue(const K& key, const T& a);
This is a deprecated version of the insert member above. It behaves
exactly the same as insert.
bool
isEmpty() const;
Returns true if there are no items in the collection, false otherwise.
size_type
occurrencesOf(const K& key) const;
Returns the number of keys j in self that compare equal to key.
size_type
occurrencesOf
(bool (*fn)(const_reference&,void*),void* d) const;
Returns the number of associations a in self such that the
expression((*fn)(a,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.
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bool
remove(const K& key);
Removes the first association with key j in self such that j compares
equal to key and returns true. Returns false if there is no such
association.
bool
remove(bool (*fn)(const_reference,void*), void* d);
Removes the first association a in self such that the expression
((*fn)(a,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 K& key);
Removes all associations with key j in self such that j compares equal to
key. Returns the number of items removed.
size_type
removeAll(bool (*fn)(const_reference,void*), void* d);
Removes all associations a in self such that the expression
((*fn)(a,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.
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map<K,T,C,allocator>&
std();
const map<K,T,C,allocator>&
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.
Related Global Operators
RWvostream&
operator<<(RWvostream& strm, const RWTValMap<K,T,C>& coll);
RWFile&
operator<<(RWFile& strm, const RWTValMap<K,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, RWTValMap<K,T,C>& coll);
RWFile&
operator>>(RWFile& strm, RWTValMap<K,T,C>& coll);
Restores the contents of the collection coll from the input stream strm.
RWvistream&
operator>>(RWvistream& strm, RWTValMap<K,T,C>*& p);
RWFile&
operator>>(RWFile& strm, RWTValMap<K,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.
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