rw_hashmap< K, V, Hash, EQ, A > Class Template Reference

Maintains a collection of mappings between two types K and V, implemented as a hash table of std::pair<const K,V> instances. More...

#include <rw/stdex/hashmap.h>

Public Types
typedef impl_type::allocator_type	allocator_type
typedef impl_type::const_iterator	const_iterator
typedef impl_type::const_pointer	const_pointer
typedef impl_type::const_reference	const_reference
typedef impl_type::difference_type	difference_type
typedef impl_type::hasher	hasher
typedef impl_type::iterator	iterator
typedef impl_type::key_equal	key_equal_type
typedef impl_type::hasher	key_hash_type
typedef impl_type::key_type	key_type
typedef impl_type::key_policy::mapped_type	mapped_type
typedef impl_type::pointer	pointer
typedef impl_type::reference	reference
typedef impl_type::size_type	size_type
typedef impl_type::value_type	value_type

Public Member Functions
	rw_hashmap (const rw_hashmap &other)
template<typename InputIterator >
	rw_hashmap (InputIterator first, InputIterator last, size_type cap=64, const hasher &h=hasher(), const key_equal_type &eq=key_equal_type())
	rw_hashmap (rw_hashmap &&other)
	rw_hashmap (size_type cap=64, const hasher &h=hasher(), const key_equal_type &eq=key_equal_type())
	~rw_hashmap (void)
iterator	begin (void)
const_iterator	begin (void) const
size_type	capacity (void) const
const_iterator	cbegin (void) const
const_iterator	cend (void) const
void	clear (void)
size_type	count (const key_type &key) const
bool	empty (void) const
iterator	end (void)
const_iterator	end (void) const
bool	equal_by_keys (const rw_hashmap &rhs) const
std::pair< iterator, iterator >	equal_range (const key_type &key)
std::pair< const_iterator, const_iterator >	equal_range (const key_type &key) const
size_type	erase (const key_type &key)
iterator	erase (iterator iter)
iterator	erase (iterator iter, iterator bound)
float	fill_ratio (void) const
iterator	find (const key_type &key)
const_iterator	find (const key_type &key) const
std::pair< iterator, bool >	insert (const value_type &val)
template<typename InputIterator >
size_type	insert (InputIterator first, InputIterator last)
iterator	insert (iterator hint, const value_type &val)
iterator	insert (iterator, value_type &&val)
std::pair< iterator, bool >	insert (value_type &&val)
iterator	lower_bound (const key_type &key)
const_iterator	lower_bound (const key_type &key) const
rw_hashmap &	operator= (const rw_hashmap &rhs)
rw_hashmap &	operator= (rw_hashmap &&rhs)
mapped_type &	operator[] (const key_type &key)
void	resize (size_t cap)
size_type	size (void) const
void	swap (rw_hashmap &other)
iterator	upper_bound (const key_type &key)
const_iterator	upper_bound (const key_type &key) const

Related Symbols
(Note that these are not member symbols.)
template<class K , class V , class Hash , class EQ , class A >
bool	operator!= (const rw_hashmap< K, V, Hash, EQ, A > &lhs, const rw_hashmap< K, V, Hash, EQ, A > &rhs)
template<class K , class V , class Hash , class EQ , class A >
bool	operator== (const rw_hashmap< K, V, Hash, EQ, A > &lhs, const rw_hashmap< K, V, Hash, EQ, A > &rhs)

Detailed Description

template<class K, class V, class Hash = RWTHash<K>, class EQ = std::equal_to<K>, class A = std::allocator<std::pair<const K, V> >>
class rw_hashmap< K, V, Hash, EQ, A >

Class rw_hashmap maintains a collection mapping between instances of K (the key) and V (the value), implemented as a hash table of std::pair<const K,V> in which there may not be more than one instance of any given K. Since this is a value-based collection, objects are copied into and out of the collection. As with all classes that meet the ANSI associative container specification, rw_hashmap provides for iterators that reference its elements. Since the contents of rw_hashset are in psuedo-random order, the only iterator ranges that will usually make sense are the results of calling equal_range(), and the entire range from begin() to end().

Hash must provide a const function that takes a single argument convertible to type K and returns a value of type size_t.

Note

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

Key equality is determined by an equality function of type EQ, which takes two arguments convertible to type K and returns a value of type bool.

Note

Any two keys that are equivalent are disallowed for this container.

Synopsis

#include <rw/stdex/hashmap.h>
rw_hashmap<K, V>;

Persistence

None

Member Typedef Documentation

allocator_type

template<class K , class V , class Hash = RWTHash<K>, class EQ = std::equal_to<K>, class A = std::allocator<std::pair<const K, V> >>

typedef impl_type::allocator_type rw_hashmap< K, V, Hash, EQ, A >::allocator_type

A type representing the allocator type for the container.

const_iterator

template<class K , class V , class Hash = RWTHash<K>, class EQ = std::equal_to<K>, class A = std::allocator<std::pair<const K, V> >>

typedef impl_type::const_iterator rw_hashmap< K, V, Hash, EQ, A >::const_iterator

A type that provides a const forward iterator over the elements in the container.

const_pointer

template<class K , class V , class Hash = RWTHash<K>, class EQ = std::equal_to<K>, class A = std::allocator<std::pair<const K, V> >>

typedef impl_type::const_pointer rw_hashmap< K, V, Hash, EQ, A >::const_pointer

A type that provides a const pointer to an element in the container.

const_reference

template<class K , class V , class Hash = RWTHash<K>, class EQ = std::equal_to<K>, class A = std::allocator<std::pair<const K, V> >>

typedef impl_type::const_reference rw_hashmap< K, V, Hash, EQ, A >::const_reference

A type that provides a const reference to an element in the container.

difference_type

template<class K , class V , class Hash = RWTHash<K>, class EQ = std::equal_to<K>, class A = std::allocator<std::pair<const K, V> >>

typedef impl_type::difference_type rw_hashmap< K, V, Hash, EQ, A >::difference_type

A signed integral type used to indicate the distance between two valid iterators on the same container.

hasher

template<class K , class V , class Hash = RWTHash<K>, class EQ = std::equal_to<K>, class A = std::allocator<std::pair<const K, V> >>

typedef impl_type::hasher rw_hashmap< K, V, Hash, EQ, A >::hasher

A type representing the hash function.

iterator

template<class K , class V , class Hash = RWTHash<K>, class EQ = std::equal_to<K>, class A = std::allocator<std::pair<const K, V> >>

typedef impl_type::iterator rw_hashmap< K, V, Hash, EQ, A >::iterator

A type that provides a forward iterator over the elements in the container.

key_equal_type

template<class K , class V , class Hash = RWTHash<K>, class EQ = std::equal_to<K>, class A = std::allocator<std::pair<const K, V> >>

typedef impl_type::key_equal rw_hashmap< K, V, Hash, EQ, A >::key_equal_type

A type representing the key equality function.

key_hash_type

template<class K , class V , class Hash = RWTHash<K>, class EQ = std::equal_to<K>, class A = std::allocator<std::pair<const K, V> >>

typedef impl_type::hasher rw_hashmap< K, V, Hash, EQ, A >::key_hash_type

Deprecated

As of SourcePro 12.5, use hasher instead.

A type representing the hash function.

key_type

template<class K , class V , class Hash = RWTHash<K>, class EQ = std::equal_to<K>, class A = std::allocator<std::pair<const K, V> >>

typedef impl_type::key_type rw_hashmap< K, V, Hash, EQ, A >::key_type

A type representing the type of keys used in the container.

mapped_type

template<class K , class V , class Hash = RWTHash<K>, class EQ = std::equal_to<K>, class A = std::allocator<std::pair<const K, V> >>

typedef impl_type::key_policy::mapped_type rw_hashmap< K, V, Hash, EQ, A >::mapped_type

A type representing the type of mapped values used in the container.

pointer

template<class K , class V , class Hash = RWTHash<K>, class EQ = std::equal_to<K>, class A = std::allocator<std::pair<const K, V> >>

typedef impl_type::pointer rw_hashmap< K, V, Hash, EQ, A >::pointer

A type that provides a pointer to an element in the container.

reference

template<class K , class V , class Hash = RWTHash<K>, class EQ = std::equal_to<K>, class A = std::allocator<std::pair<const K, V> >>

typedef impl_type::reference rw_hashmap< K, V, Hash, EQ, A >::reference

A type that provides a reference to an element in the container.

size_type

template<class K , class V , class Hash = RWTHash<K>, class EQ = std::equal_to<K>, class A = std::allocator<std::pair<const K, V> >>

typedef impl_type::size_type rw_hashmap< K, V, Hash, EQ, A >::size_type

An unsigned integral type used for counting the number of elements in the container.

value_type

template<class K , class V , class Hash = RWTHash<K>, class EQ = std::equal_to<K>, class A = std::allocator<std::pair<const K, V> >>

typedef impl_type::value_type rw_hashmap< K, V, Hash, EQ, A >::value_type

A type representing the value stored in the container.

Constructor & Destructor Documentation

rw_hashmap() [1/4]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::rw_hashmap ( size_type cap = 64, const hasher & h = hasher(), const key_equal_type & eq = key_equal_type() )

inline

Constructs an empty rw_hashmap with cap buckets, using h as the hash function object, and eq as the equality function object.

Note

If the value specified for cap is zero, the default number of buckets is used.

rw_hashmap() [2/4]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::rw_hashmap ( const rw_hashmap< K, V, Hash, EQ, A > & other )

inline

Constructs an rw_hashmap that is a copy of other. Each element from other is copied into self.

rw_hashmap() [3/4]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::rw_hashmap ( rw_hashmap< K, V, Hash, EQ, A > && other )

inline

Move constructor. The constructed rw_hashmap takes ownership of the data owned by other.

Condition:

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

rw_hashmap() [4/4]

template<class K , class V , class Hash , class EQ , class A >

template<typename InputIterator >

rw_hashmap< K, V, Hash, EQ, A >::rw_hashmap ( InputIterator first, InputIterator last, size_type cap = 64, const hasher & h = hasher(), const key_equal_type & eq = key_equal_type() )

inline

Constructs an rw_hashmap containing a copy of the pair elements in the range [first, last). The rw_hashmap instance has cap buckets, uses h as its hash function object, and eq as its equality function object.

InputIterator is an input iterator type that points to elements that are convertible to value_type objects.

Note

If the value specified for cap is zero, the default number of buckets is used.

~rw_hashmap()

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::~rw_hashmap ( void )

inline

The destructor releases the memory used by the container's implementation.

Member Function Documentation

begin() [1/2]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::iterator rw_hashmap< K, V, Hash, EQ, A >::begin ( void )

inline

Returns an iterator referring to the first element in the container.

If the container is empty, returns end().

begin() [2/2]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::const_iterator rw_hashmap< K, V, Hash, EQ, A >::begin ( void ) const

inline

Returns an iterator referring to the first element in the container.

If the container is empty, returns end().

capacity()

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::size_type rw_hashmap< K, V, Hash, EQ, A >::capacity ( void ) const

inline

Returns the number of buckets in the container.

cbegin()

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::const_iterator rw_hashmap< K, V, Hash, EQ, A >::cbegin ( void ) const

inline

Returns an iterator referring to the first element in the container.

If the container is empty, returns end().

cend()

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::const_iterator rw_hashmap< K, V, Hash, EQ, A >::cend ( void ) const

inline

Returns an iterator referring to the element after the last element in the container.

Dereferencing the iterator returned by this function results in undefined behavior.

clear()

template<class K , class V , class Hash , class EQ , class A >

void rw_hashmap< K, V, Hash, EQ, A >::clear ( void )

inline

Removes all items in the container.

count()

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::size_type rw_hashmap< K, V, Hash, EQ, A >::count ( const key_type & key ) const

inline

Returns the number of items in self whose key compares equal to key according to the associated equality function object.

empty()

template<class K , class V , class Hash , class EQ , class A >

bool rw_hashmap< K, V, Hash, EQ, A >::empty ( void ) const

inline

Returns true if there are no items in the container.

end() [1/2]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::iterator rw_hashmap< K, V, Hash, EQ, A >::end ( void )

inline

Returns an iterator referring to the element after the last element in the container.

Dereferencing the iterator returned by this function results in undefined behavior.

end() [2/2]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::const_iterator rw_hashmap< K, V, Hash, EQ, A >::end ( void ) const

inline

Returns an iterator referring to the element after the last element in the container.

Dereferencing the iterator returned by this function results in undefined behavior.

equal_by_keys()

template<class K , class V , class Hash , class EQ , class A >

bool rw_hashmap< K, V, Hash, EQ, A >::equal_by_keys ( const rw_hashmap< K, V, Hash, EQ, A > & rhs ) const

inline

Returns true if the container and rhs have the same number of elements, and for each value_type in lhs, there is a value_type in rhs that has a first part (the key) for which the equality function object returns true. The second part (the value) of the pair is not compared.

equal_range() [1/2]

template<class K , class V , class Hash , class EQ , class A >

std::pair< typename rw_hashmap< K, V, Hash, EQ, A >::iterator, typename rw_hashmap< K, V, Hash, EQ, A >::iterator > rw_hashmap< K, V, Hash, EQ, A >::equal_range ( const key_type & key )

inline

Returns the bounds of the subrange representing all values in the container whose key compares equal to key according to the associated equality function object. If no items in the container compare equal to key, returns end() for both iterators.

equal_range() [2/2]

template<class K , class V , class Hash , class EQ , class A >

std::pair< typename rw_hashmap< K, V, Hash, EQ, A >::const_iterator, typename rw_hashmap< K, V, Hash, EQ, A >::const_iterator > rw_hashmap< K, V, Hash, EQ, A >::equal_range ( const key_type & key ) const

inline

Returns the bounds of the subrange representing all values in the container whose key compares equal to key according to the associated equality function object. If no items in the container compare equal to key, returns end() for both iterators.

erase() [1/3]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::size_type rw_hashmap< K, V, Hash, EQ, A >::erase ( const key_type & key )

inline

Removes the item in the container whose key compares equal to key according to the equality function object. Returns 1 if the item was found and removed, 0 otherwise.

erase() [2/3]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::iterator rw_hashmap< K, V, Hash, EQ, A >::erase ( iterator iter )

inline

Removes the element referenced by iter and returns an iterator referencing the next element. If iter does not reference an item in self, the result is undefined.

erase() [3/3]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::iterator rw_hashmap< K, V, Hash, EQ, A >::erase ( iterator iter, iterator bound )

inline

Removes each element in the range [first, last). Returns an iterator referencing last. If first does not reference an item in self (and if first and last are not equal), the behavior is undefined.

fill_ratio()

template<class K , class V , class Hash , class EQ , class A >

float rw_hashmap< K, V, Hash, EQ, A >::fill_ratio ( void ) const

inline

Returns the ratio of the number of items in the container to the number of buckets.

find() [1/2]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::iterator rw_hashmap< K, V, Hash, EQ, A >::find ( const key_type & key )

inline

Returns the first item in self whose key compares equal to key according to the associated equality function object. If no items in the container compare equal to key, returns end().

find() [2/2]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::const_iterator rw_hashmap< K, V, Hash, EQ, A >::find ( const key_type & key ) const

inline

Returns the first item in self whose key compares equal to key according to the associated equality function object. If no items in the container compare equal to key, returns end().

insert() [1/5]

template<class K , class V , class Hash , class EQ , class A >

std::pair< typename rw_hashmap< K, V, Hash, EQ, A >::iterator, bool > rw_hashmap< K, V, Hash, EQ, A >::insert ( const value_type & val )

inline

Inserts a copy of val into the container. If an element in the container has the same key as val, an iterator to the existing element in the collection is returned with an associated status of false. Otherwise, the value val is inserted into the collection and an iterator to the new item is returned, along with the status true.

insert() [2/5]

template<class K , class V , class Hash , class EQ , class A >

template<typename InputIterator >

rw_hashmap< K, V, Hash, EQ, A >::size_type rw_hashmap< K, V, Hash, EQ, A >::insert ( InputIterator first, InputIterator last )

inline

For each value in the range [first, last), inserts a copy of the value into self. If an element in the container has the same key as the value, the value is not inserted. Returns the number of elements inserted.

InputIterator is an input iterator type that points to elements that are convertible to value_type objects.

Note

first and last must not be iterators into self.

insert() [3/5]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::iterator rw_hashmap< K, V, Hash, EQ, A >::insert ( iterator hint, const value_type & val )

inline

Inserts a copy of val into the container. If an element in the container has the same key as val, an iterator to the existing element in the collection is returned with an associated status of false. Otherwise, the value val is inserted into the collection and an iterator to the new item is returned, along with the status true.

The parameter hint is ignored.

insert() [4/5]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::iterator rw_hashmap< K, V, Hash, EQ, A >::insert ( iterator hint, value_type && val )

inline

Inserts val into the container. If an element in the container has the same key as val, an iterator to the existing element in the collection is returned with an associated status of false. Otherwise, the value val is inserted into the collection and an iterator to the new item is returned, along with the status true.

The parameter hint is ignored.

Condition:

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

insert() [5/5]

template<class K , class V , class Hash , class EQ , class A >

std::pair< typename rw_hashmap< K, V, Hash, EQ, A >::iterator, bool > rw_hashmap< K, V, Hash, EQ, A >::insert ( value_type && val )

inline

Inserts val into the container. If an element in the container has the same key as val, an iterator to the existing element in the collection is returned with an associated status of false. Otherwise, the value val is inserted into the collection and an iterator to the new item is returned, along with the status true.

Condition:

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

lower_bound() [1/2]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::iterator rw_hashmap< K, V, Hash, EQ, A >::lower_bound ( const key_type & key )

inline

Equivalent to equal_range(key).first.

lower_bound() [2/2]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::const_iterator rw_hashmap< K, V, Hash, EQ, A >::lower_bound ( const key_type & key ) const

inline

Equivalent to equal_range(key).first.

operator=() [1/2]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A > & rw_hashmap< K, V, Hash, EQ, A >::operator= ( const rw_hashmap< K, V, Hash, EQ, A > & rhs )

inline

Replaces the contents of self with copies of the contents of rhs. The capacity, hash function object and equality function object are replaced by the respective objects from rhs.

operator=() [2/2]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A > & rw_hashmap< K, V, Hash, EQ, A >::operator= ( rw_hashmap< K, V, Hash, EQ, A > && rhs )

inline

Replaces the contents of self with the contents moved from rhs. The capacity, hash function object and equality function objects are moved from the respective objects in rhs.

Condition:

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

operator[]()

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::mapped_type & rw_hashmap< K, V, Hash, EQ, A >::operator[] ( const key_type & key )

inline

Returns a reference to a mapped_type in the container whose key is equal to key according to the associated equality function object. If a key equal to key is not found in the collection, a default constructed mapped_type is created and inserted, and a reference to that instance is returned.

Note

This function requires that mapped_type is default constructible.

resize()

template<class K , class V , class Hash , class EQ , class A >

void rw_hashmap< K, V, Hash, EQ, A >::resize ( size_t cap )

inline

Sets the number of buckets to cap. Each item in the container is rehashed according to the new number of buckets.

Note

If cap is 0, it is ignored.

size()

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::size_type rw_hashmap< K, V, Hash, EQ, A >::size ( void ) const

inline

Returns the number of items in the container.

swap()

template<class K , class V , class Hash , class EQ , class A >

void rw_hashmap< K, V, Hash, EQ, A >::swap ( rw_hashmap< K, V, Hash, EQ, A > & other )

inline

Exchanges the contents of self with other, including the Hash and EQ objects. This method does not copy or destroy any of the items exchanged but exchanges the underlying hash tables.

upper_bound() [1/2]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::iterator rw_hashmap< K, V, Hash, EQ, A >::upper_bound ( const key_type & key )

inline

Equivalent to equal_range(key).second.

upper_bound() [2/2]

template<class K , class V , class Hash , class EQ , class A >

rw_hashmap< K, V, Hash, EQ, A >::const_iterator rw_hashmap< K, V, Hash, EQ, A >::upper_bound ( const key_type & key ) const

inline

Equivalent to equal_range(key).second.

Friends And Related Symbol Documentation

operator!=()

template<class K , class V , class Hash , class EQ , class A >

bool operator!= ( const rw_hashmap< K, V, Hash, EQ, A > & lhs, const rw_hashmap< K, V, Hash, EQ, A > & rhs )

related

Equivalent to !(lhs == rhs).

operator==()

template<class K , class V , class Hash , class EQ , class A >

bool operator== ( const rw_hashmap< K, V, Hash, EQ, A > & lhs, const rw_hashmap< K, V, Hash, EQ, A > & rhs )

related

Returns true if lhs and rhs have the same number of elements, and for each item in lhs, there is an item in rhs whose first part (the key) compares equal according to the equality function object and whose second part (the value) compares equal according to operator==().

Note

If only the keys of the values need to be compared for equality, use rw_hashmap::equal_by_keys() instead.