bslh::FibonacciBadHashWrapper< HASH > Class Template Reference

#include <bslh_fibonaccibadhashwrapper.h>

Public Member Functions
	FibonacciBadHashWrapper ()
	FibonacciBadHashWrapper (const HASH &hash)
	Create a FibonacciBadHashWrapper having the specified hash.
	FibonacciBadHashWrapper (const FibonacciBadHashWrapper &original)=default
	~FibonacciBadHashWrapper ()=default
FibonacciBadHashWrapper &	operator= (const FibonacciBadHashWrapper &rhs)=default
template<class KEY >
size_t	operator() (const KEY &key) const

Static Public Attributes
static const bsls::Types::Uint64	k_FIBONACCI_HASH_MULTIPLIER = 11400714819323198485ull

Detailed Description

template<class HASH>
class bslh::FibonacciBadHashWrapper< HASH >

This class provides a hash algorithm wrapper that improves the distribution of varying bits from the HASH applied to the KEY.

See bslh_fibonaccibadhashwrapper

Constructor & Destructor Documentation

FibonacciBadHashWrapper() [1/3]

template<class HASH >

bslh::FibonacciBadHashWrapper< HASH >::FibonacciBadHashWrapper ( )

inline

Create a FibonacciBadHashWrapper having a default constructed hash.

FibonacciBadHashWrapper() [2/3]

template<class HASH >

bslh::FibonacciBadHashWrapper< HASH >::FibonacciBadHashWrapper ( const HASH &  hash )

inlineexplicit

FibonacciBadHashWrapper() [3/3]

template<class HASH >

bslh::FibonacciBadHashWrapper< HASH >::FibonacciBadHashWrapper ( const FibonacciBadHashWrapper< HASH > &  original )

default

~FibonacciBadHashWrapper()

template<class HASH >

bslh::FibonacciBadHashWrapper< HASH >::~FibonacciBadHashWrapper ( )

default

Member Function Documentation

operator()()

template<class HASH >

template<class KEY >

size_t bslh::FibonacciBadHashWrapper< HASH >::operator() ( const KEY &  key ) const

inline

Return the hash of the specified key, computed as the product of the result of the hash function supplied at construction and k_FIBONACCI_HASH_MULTIPLIER.

operator=()

template<class HASH >

FibonacciBadHashWrapper & bslh::FibonacciBadHashWrapper< HASH >::operator= ( const FibonacciBadHashWrapper< HASH > &  rhs )

default

Member Data Documentation

k_FIBONACCI_HASH_MULTIPLIER

template<class HASH >

const bsls::Types::Uint64 bslh::FibonacciBadHashWrapper< HASH >::k_FIBONACCI_HASH_MULTIPLIER = 11400714819323198485ull

static

The value corresponds to:

2^64 / phi - 1

where phi is the Golden Ratio and 1 is subtracted to avoid the value being a multiple of 2 (that would throw away one bit of information from the resultant hash value). See https://en.wikipedia.org/wiki/Hash_function#Fibonacci_hashing.

---

The documentation for this class was generated from the following file:

• bslh_fibonaccibadhashwrapper.h