SBCContainerHashMap< KeyType, ValueType, HashMapFunctor, KeyComparator > Class Template Reference

This template class describes a hashtable-based map. More...

The hash table
unsigned int	numberOfEntries
	The number of entries in the hash map.
SBCContainerVector< SBCContainerHashMapEntry< KeyType, ValueType > * > *	hashMap
	The hash table.

Constructors and destructors
	SBCContainerHashMap (unsigned int nElements=0)
	Creates a new hash map.
	SBCContainerHashMap (const SBCContainerHashMap &hashMap)
	Copy constructor.
	SBCContainerHashMap (SBCContainerHashMap &&hashMap)
	Move constructor.
virtual	~SBCContainerHashMap ()
	Deletes the hash map.

Operators
SBCContainerHashMap &	operator= (const SBCContainerHashMap &hashMap)
	Copy assignment.
SBCContainerHashMap &	operator= (SBCContainerHashMap &&hashMap)
	Move assignment.

Insertion and look-up
void	clear ()
	Erases all entries in the hash map.
SBCContainerHashMapEntry< KeyType, ValueType > *	insert (const KeyType &key, const ValueType &value)
	Inserts an element in the hash map.
bool	erase (const KeyType &key)
	Attempts to erase an entry with a specific key and returns true if successful.
bool	hasValue (const KeyType &key) const
	Returns true if the key has an associated value.
bool	getValue (const KeyType &key, ValueType &value) const
	Returns true if the key has an associated value and puts it in the value, else returns false.
std::optional< ValueType >	getValue (const KeyType &key) const
	Returns the value associated to the key if found.
unsigned int	size () const
	The number of entries in the hash map.
bool	empty () const
	Returns true when the hash map contains no entry.

Iterators
iterator	begin ()
	Returns an iterator that points to the beginning of the hash map.
const_iterator	begin () const
	Returns an iterator that points to the beginning of the hash map.
ValueType &	operator[] (const KeyType &key)
	Returns a reference to the value mapped to the key, which is inserted if necessary.
iterator	find (const KeyType &key)
	Finds a key in the hash map.
const_iterator	find (const KeyType &key) const
	Finds a key in the hash map.
iterator	end ()
	Returns an iterator that points to the end of the hash map.
const_iterator	end () const
	Returns an iterator that points to the end of the hash map.
std::map< KeyType, ValueType >	toStdMap () const
	Returns a std map containing the same (key, value) pairs.

Debugging
unsigned int	getMemoryFootprint () const
	Returns the memory footprint of the hash map.

Detailed Description

template<class KeyType, class ValueType, class HashMapFunctor = SBCContainerHashMapFunctor<KeyType>, class KeyComparator = SBCContainerHashMapKeyComparator<KeyType>>
class SBCContainerHashMap< KeyType, ValueType, HashMapFunctor, KeyComparator >

Parameters

KeyType	The type of keys
ValueType	The type of values
HashMapFunctor	The hash map functor, used to hash keys (by default, this is a SBCContainerHashMapFunctor<KeyType>)
KeyComparator	The key comparator, used to compare keys (by default, this is a SBCContainerHashMapKeyComparator<KeyType>)

This template class describes a hashtable-based map. This container is used for example to index objects (see SBCContainerIndexer), and may be used to efficiently map keys to values:

SBVector<SBAtom*> v;
SBHashMap<SBAtom*, unsigned int> h;
 
// create atoms and map them to integers
 
for (unsigned int i = 0; i<10; i++) {
 
    v.push_back(new SBAtom(SBElement::Carbon));
    h.insert(v[i], 6 * i + 17)
 
}
 
// print integers associated to atoms
 
unsigned int j = 0;
 
for (unsigned int i = 0; i < 10; i++)
    if (h.getValue(v[i], j)) std::cout << j << '\n';

Short name: SBHashMap

See also

SB_FOR