RWTFunctorMapR1< SR, Key > Class Template Reference
[Functor Map]

A functor map that takes only one argument at invocation time, and returns a value. More...

#include <rw/functor/map/RWTFunctorMapR1.h>

Inheritance diagram for RWTFunctorMapR1< SR, Key >:

List of all members.

Public Types
typedef Key	key_type
typedef unsigned(*	hash_function )(const Key &)
Public Member Functions
	RWTFunctorMapR1 (hash_function hf, size_t size=RW_FUNCTOR_MAP_CAPACITY)
	RWTFunctorMapR1 (const RWTFunctorMapR1< SR, Key > &second)
	~RWTFunctorMapR1 (void)
RWTFunctorMapR1< SR, Key > &	operator= (const RWTFunctorMapR1< SR, Key > &second)
SR	operator() (Key key) const
RWTFunctorMapR1Imp< SR, Key > &	body (void) const
bool	add (Key key, RWTFunctorR0< SR > functor)
bool	remove (Key key)
bool	contains (Key key) const
bool	find (Key key, RWTFunctorR0< SR > &functor) const
void	resize (size_t size)
void	clear (void)
size_t	entries (void) const
void	setDefault (RWTFunctorR0< SR > functor)
RWTFunctorR0< SR >	getDefault (void) const

---

Detailed Description

template<class SR, class Key>
class RWTFunctorMapR1< SR, Key >

The RWTFunctorMapR1 class represents the functor maps that take only one argument at invocation time, and return a value. Since this one argument is the key into the map, the functors that are held in the map do not take any arguments at all; they are RWTFunctorR0 functors.

Functor maps allow functors to be grouped together in a key/value table structure. They add functors to the map with a corresponding key of type key_type, later using it to invoke the desired functor.

Examples

 #include <rw/cstring.h>
 #include <rw/functor/functorR0.h>
 #include <rw/functor/map/RWTFunctorMapR1.h>
 
 // Functions that we want to wrap in functors:
 class BankAccount{
    float getBalance(){ return 1234.56; }
    float getInterest(){ return 61.51; }
 };
 
 int main () {
 
   BankAccount myAcct;
 
   // Create new RWTFunctorR0s to be the values in the map.
   RWTFunctorR0<float> balanceFunctor = rwtMakeFunctorR0(
             (float(*)(void))0, myAcct, &BankAccount::getBalance);
   RWTFunctorR0<float> interestFunctor = rwtMakeFunctorR0(
             (float(*)(void))0, myAcct, &BankAccount::getInterest);
 
   // Create keys with which to associate the values.
   RWCString balanceKey = "balance";
   RWCString interestKey = "interest";
 
   // Declare a new map. A complete, but empty instance now exists.
   RWTFunctorMapR1<float,RWCString> fmap(RWCString::hash);
 
   // Add something to the map to make it useful.
   fmap.add(balanceKey, balanceFunctor);
   fmap.add(interestKey, interestFunctor);
 
   // Invoking the map with the key "balance" results in the
   // balanceFunctor being called.
   float balance = fmap("balance");
 
   // Invoking the map with the key "interest" results in the
   // interestFunctor being called.
   float interest = fmap("interest");
 
   cout << "Account balance is " << balance << endl;
   cout << "Interest earned this year is " << interest << endl;
 
   return 0;
 }

Program output:

 Account balance is 1234.56
 Interest earned this year is 61.51

---

Member Typedef Documentation

template<class SR, class Key>

typedef unsigned(* RWTFunctorMapR1< SR, Key >::hash_function)(const Key &)

The signature of the hash function.

template<class SR, class Key>

typedef Key RWTFunctorMapR1< SR, Key >::key_type

The type of the key.

---

Constructor & Destructor Documentation

template<class SR, class Key>

RWTFunctorMapR1< SR, Key >::RWTFunctorMapR1	(	hash_function	hf,
		size_t	size = RW_FUNCTOR_MAP_CAPACITY
	)

Constructs an empty map instance. This creates a complete RWTFunctorMapR1 instance, but the map will contain no entries. The size parameter has a default value of RW_FUNCTOR_MAP_CAPACITY, which is defined in rw/functor/map/pkgdefs.h.

template<class SR, class Key>

RWTFunctorMapR1< SR, Key >::RWTFunctorMapR1

(

const RWTFunctorMapR1< SR, Key > &

second

)

Copy constructor. Constructs a new functor map instance which then shares its representation with the functor map second.

template<class SR, class Key>

RWTFunctorMapR1< SR, Key >::~RWTFunctorMapR1

(

void

)

Destructor.

---

Member Function Documentation

template<class SR, class Key>

bool RWTFunctorMapR1< SR, Key >::add	(	Key	key,
		RWTFunctorR0< SR >	functor
	)

Adds the specified functor to the functor map with the corresponding key. If an entry already exists with an equivalent key, the addition fails and false is returned.

template<class SR, class Key>

RWTFunctorMapR1Imp<SR,Key>& RWTFunctorMapR1< SR, Key >::body

(

void

)

const

Gets a reference for the body instance, if any; otherwise, throws an RWTHRInvalidPointer exception.

Reimplemented from RWTFunctorR1< SR, Key >.

template<class SR, class Key>

void RWTFunctorMapR1< SR, Key >::clear

(

void

)

Clears the functor map of all entries.

template<class SR, class Key>

bool RWTFunctorMapR1< SR, Key >::contains

(

Key

key

)

const

Returns true if the functor map contains an entry with key equivalent to the given key.

template<class SR, class Key>

size_t RWTFunctorMapR1< SR, Key >::entries

(

void

)

const

Returns the number of entries in the functor map.

template<class SR, class Key>

bool RWTFunctorMapR1< SR, Key >::find	(	Key	key,
		RWTFunctorR0< SR > &	functor
	)			const

Finds the entry in the functor map with key equivalent to the given key, and returns it via the reference parameter functor. Returns true if the key is found, and otherwise, returns false. In the case where a matching key is not found, but a default functor exists, this sets the reference parameter functor to the default functor, but returns false. If no match is found, and there is no default functor, this throws an RWTHRInternalError exception.

template<class SR, class Key>

RWTFunctorR0<SR> RWTFunctorMapR1< SR, Key >::getDefault

(

void

)

const

Returns the map's default functor. This functor is used whenever an invalid key accesses the functor map.

template<class SR, class Key>

SR RWTFunctorMapR1< SR, Key >::operator()

(

Key

key

)

const

Invokes the functor in the map that is associated with a key which is equivalent to the given key. If there is no matching key, and a default functor has been set, calls the default. If there is no default, and no matching key, an RWTHRInternalError exception is thrown.

Reimplemented from RWTFunctorR1< SR, Key >.

template<class SR, class Key>

RWTFunctorMapR1<SR,Key>& RWTFunctorMapR1< SR, Key >::operator=

(

const RWTFunctorMapR1< SR, Key > &

second

)

Assignment operator. Binds this functor map instance to the representation of the second map instance.

template<class SR, class Key>

bool RWTFunctorMapR1< SR, Key >::remove

(

Key

key

)

Removes the entry, if it exists, with key equivalent to the given key, and returns true. If no such entry exists, returns false.

template<class SR, class Key>

void RWTFunctorMapR1< SR, Key >::resize

(

size_t

size

)

Changes the size of the map to size. This is an expensive operation, since the entire map must be re-created. Size can be set at construction time via the size parameter of the constructor.

template<class SR, class Key>

void RWTFunctorMapR1< SR, Key >::setDefault

(

RWTFunctorR0< SR >

functor

)

Sets functor as the default functor. This functor is used whenever an invalid key is used to access the functor map.