GaudiUtils::Hash< T > Class Template Reference

#include <GaudiKernel/Hash.h>

Inheritance diagram for GaudiUtils::Hash< T >:

[legend]

List of all members.

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Detailed Description

template<class T>
class GaudiUtils::Hash< T >

Simple hash function based on Stroustrup example.

It provides correct handling of pointers, std::string and char*.

Author:

Marco Clemencic

Date:

2005-10-07

Definition at line 21 of file Hash.h.

Public Types
enum	{ bucket_size = 4, min_buckets = 8 }
Public Member Functions
size_t	operator() (const T &key) const
bool	operator() (const T &key1, const T &key2) const
template<>
size_t	operator() (const int &key) const
template<>
size_t	operator() (const unsigned int &key) const
template<>
size_t	operator() (const long &key) const
template<>
size_t	operator() (const unsigned long &key) const
template<>
size_t	operator() (const long long &key) const
template<>
size_t	operator() (const unsigned long long &key) const
template<>
size_t	operator() (const std::string &key) const
template<>
size_t	operator() (const char *key) const
Protected Attributes
std::less< T >	comp
	comparison operator needed for VC++

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Member Enumeration Documentation

template<class T>

anonymous enum

Enumerator:

bucket_size
min_buckets

Definition at line 25 of file Hash.h.

         { // parameters for hash table
      bucket_size = 4,    // 0 < bucket_size
      min_buckets = 8};   // min_buckets = 2 ^^ N, 0 < N

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Member Function Documentation

template<class T>

size_t GaudiUtils::Hash< T >::operator()

(

const T &

key

)

const [inline]

Definition at line 58 of file Hash.h.

                                                  {
    size_t res = 0 ;
    size_t len = sizeof(T) ;
    const char* p = reinterpret_cast<const char*>( &key );
    while( len-- ) { res = ( res << 1 ) ^ *p; ++p; }
    return res;
  }

template<class T>

bool GaudiUtils::Hash< T >::operator()	(	const T &	key1,
		const T &	key2
	)			const [inline]

Definition at line 29 of file Hash.h.

                                                                  { 
      // test if key1 ordered before key2
      return comp(key1,key2);
    }

template<>

size_t GaudiUtils::Hash< int >::operator()

(

const int &

key

)

const [inline]

Definition at line 67 of file Hash.h.

{ return (size_t)key; }

template<>

size_t GaudiUtils::Hash< unsigned int >::operator()

(

const unsigned int &

key

)

const [inline]

Definition at line 70 of file Hash.h.

{ return (size_t)key; }

template<>

size_t GaudiUtils::Hash< long >::operator()

(

const long &

key

)

const [inline]

Definition at line 73 of file Hash.h.

{ return (size_t)key; }

template<>

size_t GaudiUtils::Hash< unsigned long >::operator()

(

const unsigned long &

key

)

const [inline]

Definition at line 76 of file Hash.h.

{ return (size_t)key; }

template<>

size_t GaudiUtils::Hash< long long >::operator()

(

const long long &

key

)

const [inline]

Definition at line 79 of file Hash.h.

{ return (size_t)key; }

template<>

size_t GaudiUtils::Hash< unsigned long long >::operator()

(

const unsigned long long &

key

)

const [inline]

Definition at line 82 of file Hash.h.

{ return (size_t)key; }   

template<>

size_t GaudiUtils::Hash< std::string >::operator()

(

const std::string &

key

)

const [inline]

Definition at line 96 of file Hash.h.

                                                                         {
    size_t res = 0 ;
    std::string::const_iterator e = key.end();
    std::string::const_iterator p = key.begin();
    while( p != e ) { res = ( res << 1 ) ^ *p; ++p; }
    return res;
  }

template<>

size_t GaudiUtils::Hash< char * >::operator()

(

const char *

key

)

const [inline]

Definition at line 105 of file Hash.h.

                                                                 {
    size_t res = 0 ;
    if ( 0 == key ) { return 0; }
    while ( *key ) { res = ( res << 1 ) ^ *key; ++key; }
    return res;
  }

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Member Data Documentation

template<class T>

std::less<T> GaudiUtils::Hash< T >::comp [protected]

comparison operator needed for VC++

Definition at line 35 of file Hash.h.

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

• /afs/cern.ch/sw/Gaudi/releases/GAUDI/GAUDI_v20r4/GaudiKernel/GaudiKernel/Hash.h