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<K,V> instances. More...

#include <rw/stdex/hashmap.h>

Public Types
typedef A	allocator_type
typedef impl_type::ConstIterator	const_iterator
typedef impl_type::const_pointer	const_pointer
typedef impl_type::const_reference	const_reference
typedef impl_type::difference_type	difference_type
typedef Hash	hasher
typedef impl_type::Iterator	iterator
typedef EQ	key_equal_type
typedef Hash	key_hash_type
typedef K	key_type
typedef V	mapped_type
typedef impl_type::pointer	pointer
typedef impl_type::reference	reference
typedef impl_type::size_type	size_type
typedef std::pair< const K, V >	value_type

Public Member Functions
	rw_hashmap (size_type sz=1024, const hasher &h=hasher(), const key_equal_type &eq=key_equal_type())
	rw_hashmap (const rw_hashmap< K, V, Hash, EQ, A > &map)
	rw_hashmap (rw_hashmap< K, V, Hash, EQ, A > &&lst)
template<typename InputIterator >
	rw_hashmap (InputIterator first, InputIterator last, size_type sz=1024, const hasher &h=hasher(), const key_equal_type &eq=key_equal_type())
	~rw_hashmap ()
iterator	begin ()
const_iterator	begin () const
	More...
size_type	capacity () const
const_iterator	cbegin () const
	More...
const_iterator	cend () const
	More...
void	clear ()
size_type	count (const key_type &key) const
bool	empty () const
iterator	end ()
const_iterator	end () const
	More...
bool	equal_by_keys (const rw_hashmap< K, V, Hash, EQ, A > &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 () const
const_iterator	find (const key_type &key) const
iterator	find (const key_type &key)
std::pair< iterator, bool >	insert (const value_type &val)
iterator	insert (iterator, const value_type &val)
std::pair< iterator, bool >	insert (value_type &&val)
	More...
iterator	insert (iterator, value_type &&val)
	More...
template<typename InputIterator >
size_type	insert (InputIterator first, InputIterator last)
iterator	lower_bound (const key_type &key)
const_iterator	lower_bound (const key_type &key) const
	More...
rw_hashmap< K, V, Hash, EQ, A > &	operator= (const rw_hashmap< K, V, Hash, EQ, A > &rhs)
rw_hashmap< K, V, Hash, EQ, A > &	operator= (rw_hashmap< K, V, Hash, EQ, A > &&rhs)
V &	operator[] (const key_type &key)
void	resize (size_t sz)
size_type	size () const
void	swap (rw_hashmap< K, V, Hash, EQ, A > &other)
iterator	upper_bound (const key_type &key)
const_iterator	upper_bound (const key_type &key) const
	More...

Related Functions
(Note that these are not member functions.)
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<K,V,Hash,EQ,A> maintains a collection of mappings between K and V, implemented as a hash table of std::pair<const K,V>. operator== must be defined for type V. Pairs with duplicate keys are not allowed. Two pairs having duplicate keys as the result of the EQ comparison, applied to the first element of each, is true.

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<K,V,Hash,EQ,A> provides for iterators that reference its elements. Operations that alter the contents of rw_hashmap<K,V,Hash,EQ,A> may invalidate other iterators that reference the container. Since the contents of rw_hashmap<K,V,Hash,EQ,A> are in pseudo-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,Hash,EQ,A=std::allocator<std::pair<const K,V> > >;

Persistence

None

Member Typedef Documentation

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

A type representing the allocator type for the container.

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::ConstIterator rw_hashmap< K, V, Hash, EQ, A >::const_iterator

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

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.

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.

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.

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

A type representing the hash function.

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.

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 EQ rw_hashmap< K, V, Hash, EQ, A >::key_equal_type

A type representing the equality function.

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 Hash rw_hashmap< K, V, Hash, EQ, A >::key_hash_type

Deprecated:

Use hasher instead.

A type representing the hash function.

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

A type representing the key of the container.

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 V rw_hashmap< K, V, Hash, EQ, A >::mapped_type

A type representing the mapped value of the container.

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.

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.

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.

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 std::pair<const K,V> rw_hashmap< K, V, Hash, EQ, A >::value_type

A type representing the container's data type.

Constructor & Destructor Documentation

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

rw_hashmap< K, V, Hash, EQ, A >::rw_hashmap ( size_type  sz = 1024, const hasher &  h = hasher(), const key_equal_type &  eq = key_equal_type()  )

inline

Constructs an empty rw_hashmap<K,V,Hash,EQ,A> with sz slots, using h as the hash object, and eq as the equality comparator.

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

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

inline

Constructs an rw_hashmap<K,V,Hash,EQ,A> that is a copy of map. Each element from map is copied into self.

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

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

inline

Move constructor. The constructed list takes ownership of the data owned by lst.

Condition:

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

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

template<typename InputIterator >

rw_hashmap< K, V, Hash, EQ, A >::rw_hashmap	(	InputIterator	first,
		InputIterator	last,
		size_type	sz = 1024,
		const hasher &	h = hasher(),
		const key_equal_type &	eq = key_equal_type()
	)

Constructs an rw_hashmap<K,V,Hash,EQ,A> containing a copy of the pair elements in the range [first, last). The rw_hashmap instance will have sz slots, use h as its hash object, and eq as its equality comparator.

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

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

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

inline

Releases the memory used by the container's implementation.

Member Function Documentation

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

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

inline

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

If the container is empty, returns end().

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

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

inline

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

If the container is empty, returns end().

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

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

inline

Returns the number of slots in the hash table that self uses.

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

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

inline

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

If the container is empty, returns end().

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

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

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

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

inline

A synonym for erase(begin(),end()) .

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

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

inline

Returns 1 if self contains a pair with its first element EQ to key, else 0.

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

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

inline

Returns true if self is empty.

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

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

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.

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

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

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

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 self and rhs have the same size, and if for each value_type in self, there is a value_type in rhs such that the EQ object in self returns true when called for the first parts of those pairs. Note that this method does not compare the V (second) part of the pair of the items, so it will run slightly faster than operator==().

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

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

inline

Returns std::pair<iterator,iterator>(lower_bound(), upper_bound()). The methods, upper_bound() and lower_bound(), have special meaning for hash-based collections.

Note

All items which are EQ to each other are in consecutive iterator locations. Thus, while equal_range() is useful, no other range (except the entire range of the hash table) is likely to be meaningful.

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

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

inline

Returns std::pair<const_iterator,const_iterator>(lower_bound(), upper_bound()). The methods, upper_bound() and lower_bound(), have special meaning for hash-based collections.

Note

All items which are EQ to each other are in consecutive iterator locations. Thus, while equal_range() is useful, no other range (except the entire range of the hash table) is likely to be meaningful.

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

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

inline

If there is a pair in self for which the first part is EQ to key, that pair is removed, and 1 is returned. Otherwise, 0 is returned.

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

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.

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

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

inline

Removes each element in the range which begins with first and is bounded by bound. Returns an iterator referencing bound. If iter does not reference an item in self (and if iter and bound are not equal), the effect is undefined.

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

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

inline

Returns the result of calculating size() / capacity().

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

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

inline

Returns an rw_hashmap<K,V,Hash,EQ,A>::const_iterator referencing the pair with key as its first element if such a pair is contained in self, else returns end().

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

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

inline

Returns an iterator referencing the pair with key as its first element, if such a pair is contained in self, else returns end().

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

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

inline

If there is no pair in self with first part EQ to the first part of val, inserts val, returning a pair with an iterator referencing the new element and true. Otherwise, returns a pair with an iterator referencing the matching value_type and false.

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

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

inline

If there is no pair in self with first part EQ to the first part of val, inserts val, returning 1. Otherwise, does nothing and returns 0. Note that the first argument is provided only for conformance with the ANSI associative container specification, and is ignored by the method since hash table look up can be done in constant time.

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

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

inline

If there is no pair in self with first part EQ to the first part of val, inserts val, returning a pair with an iterator referencing the new element and true. Otherwise, returns a pair with an iterator referencing the matching value_type and false.

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

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

inline

If there is no pair in self with first part EQ to the first part of val, inserts val, returning 1. Otherwise, does nothing and returns 0. Note that the first argument is provided only for conformance with the ANSI associative container specification, and is ignored by the method since hash table look up can be done in constant time.

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

template<typename InputIterator >

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

inline

For each element in the range [first, last), inserts a copy of the element into self. If an element with the same key (according to EQ) already exists in self, the insertion is skipped. Returns the number of elements inserted.

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

Note

first and last must not be iterators into self.

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

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

inline

Returns the lower bound of key in self. This has a special meaning for hash-based collections.

Since hash tables are intrinsically unordered, we have relaxed the meaning very slightly so that lower_bound() returns an iterator which points to one of the following:

• "just past" the hash table slot where key would have been but was not.
• the "first" iterator which references something EQ to key.

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

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

inline

Returns the lower bound of key in self. This has a special meaning for hash-based collections.

Since hash tables are intrinsically unordered, we have relaxed the meaning very slightly so that lower_bound() returns an iterator which points to one of the following:

• "just past" the hash table slot where key would have been but was not.
• the "first" iterator which references something EQ to key.

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

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

Sets self to have the same capacity, Hash and EQ as rhs, removes all self's current contents, and replaces them with copies of the elements in rhs.

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

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

inline

Move assignment. Self takes ownership of the data owned by rhs.

Condition:

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

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

V& rw_hashmap< K, V, Hash, EQ, A >::operator[]

(

const key_type &

key

)

Returns a reference to the V part of a pair held in self which has a part EQ to key, either by finding such a pair, or inserting one (in which case the reference is to an instance of V created by its default constructor).

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

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

inline

Resizes self's hash table to have sz slots and re-hashes all self's elements into the new table. Can be very expensive if self holds many elements.

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

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

inline

Returns the number of pairs currently held in self.

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

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.

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

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

inline

Returns the upper bound of key in self. This has a special meaning for hash-based collections.

Since hash tables are intrinsically unordered, we have relaxed the meaning very slightly so that upper_bound() returns an iterator which points to one of the following:

• "just past" the hash table slot where key would have been but was not.
• "just past" the "last" iterator which references something EQ to key.

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

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

inline

Returns the upper bound of key in self. This has a special meaning for hash-based collections.

Since hash tables are intrinsically unordered, we have relaxed the meaning very slightly so that upper_bound() returns an iterator which points to one of the following:

• "just past" the hash table slot where key would have been but was not.
• "just past" the "last" iterator which references something EQ to key.

Friends And Related Function Documentation

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).

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 value_type in lhs, there is a value_type in rhs that has a first part for which the EQ object in self returns true, and a second part for which operator==() returns true. The need to test both parts means that this operator is slightly slower than the method equal_by_keys().