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collate::hash

Determines the hash value of sequence according to their facet-specific rules.

long hash( 
   const CharType* _First, 
   const CharType* _Last 
) const;

Parameters

  • _First
    A pointer to the first character in the sequence whose has value is to be determined.

  • _Last
    A pointer to the last character in the sequence whose has value is to be determined.

Return Value

A hash value of type long for the sequence.

Remarks

The member function returns do_hash(_First, _Last).

A hash value can be useful, for example, in distributing sequences pseudo-randomly across an array of lists.

Example

// collate_hash.cpp
// compile with: /EHsc
#include <locale>
#include <iostream>
#include <tchar.h>
using namespace std;

int main( )   
{
   locale loc ( "German_germany" );
   _TCHAR * s1 = _T("\x00dfzz abc."); // \x00df is the German sharp-s (looks like beta), it comes before z in the alphabet
   _TCHAR * s2 = _T("zzz abc."); // \x00df is the German sharp-s (looks like beta), it comes before z in the alphabet

   long r1 = use_facet< collate<_TCHAR> > ( loc ).
      hash (s1, &s1[_tcslen( s1 )-1 ]);
   long r2 =  use_facet< collate<_TCHAR> > ( loc ).
      hash (s2, &s2[_tcslen( s2 )-1 ] );
   cout << r1 << " " << r2 << endl;
}
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Requirements

Header: <locale>

Namespace: std

See Also

Reference

collate Class