hash_fun.h

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// 'struct hash' from SGI -*- C++ -*-

// Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
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// any later version.

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// GNU General Public License for more details.

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// As a special exception, you may use this file as part of a free software
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/*
 * Copyright (c) 1996-1998
 * Silicon Graphics Computer Systems, Inc.
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Silicon Graphics makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 *
 * Copyright (c) 1994
 * Hewlett-Packard Company
 *
 * Permission to use, copy, modify, distribute and sell this software
 * and its documentation for any purpose is hereby granted without fee,
 * provided that the above copyright notice appear in all copies and
 * that both that copyright notice and this permission notice appear
 * in supporting documentation.  Hewlett-Packard Company makes no
 * representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied warranty.
 *
 */

#ifndef _HASH_FUN_H
#define _HASH_FUN_H 1

#include <cstddef>

namespace __gnu_cxx
{
  using std::size_t;

  template <class _Key> struct hash { };

  inline size_t
  __stl_hash_string(const char* __s)
  {
    unsigned long __h = 0;
    for ( ; *__s; ++__s)
      __h = 5*__h + *__s;
    return size_t(__h);
  }

  template<> struct hash<char*>
  {
    size_t operator()(const char* __s) const
    { return __stl_hash_string(__s); }
  };

  template<> struct hash<const char*>
  {
    size_t operator()(const char* __s) const
    { return __stl_hash_string(__s); }
  };

  template<> struct hash<char>
  { size_t operator()(char __x) const { return __x; } };

  template<> struct hash<unsigned char>
  { size_t operator()(unsigned char __x) const { return __x; } };

  template<> struct hash<signed char>
  { size_t operator()(unsigned char __x) const { return __x; } };

  template<> struct hash<short>
  { size_t operator()(short __x) const { return __x; } };

  template<> struct hash<unsigned short>
  { size_t operator()(unsigned short __x) const { return __x; } };

  template<> struct hash<int>
  { size_t operator()(int __x) const { return __x; } };

  template<> struct hash<unsigned int>
  { size_t operator()(unsigned int __x) const { return __x; } };

  template<> struct hash<long>
  { size_t operator()(long __x) const { return __x; } };

  template<> struct hash<unsigned long>
  { size_t operator()(unsigned long __x) const { return __x; } };
} // namespace __gnu_cxx

#endif

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