_string_hash.h

来自「MONA是为数不多的C++语言编写的一个很小的操作系统」· C头文件 代码 · 共 71 行

/*
 * Copyright (c) 1997-1999
 * Silicon Graphics Computer Systems, Inc.
 *
 * Copyright (c) 1999 
 * Boris Fomitchev
 *
 * This material is provided "as is", with absolutely no warranty expressed
 * or implied. Any use is at your own risk.
 *
 * Permission to use or copy this software for any purpose is hereby granted 
 * without fee, provided the above notices are retained on all copies.
 * Permission to modify the code and to distribute modified code is granted,
 * provided the above notices are retained, and a notice that the code was
 * modified is included with the above copyright notice.
 *
 */

#ifndef _STLP_STRING_HASH_H
# define _STLP_STRING_HASH_H

#ifndef _STLP_HASH_FUN_H
# include <stl/_hash_fun.h>
#endif

#ifndef _STLP_STRING_H
# include <stl/_string.h>
#endif

_STLP_BEGIN_NAMESPACE

template <class _CharT, class _Traits, class _Alloc>
_STLP_INLINE_LOOP size_t
__stl_string_hash(const basic_string<_CharT,_Traits,_Alloc>& __s) {
  unsigned long __h = 0;
  typedef typename basic_string<_CharT,_Traits,_Alloc>::const_pointer const_ptr;
  size_t __len = __s.size();
  const _CharT* __data = __s.data();
  for ( size_t __i = 0; __i < __len; ++__i)
    __h = 5*__h + __data[__i];
  return size_t(__h);
}

#ifdef _STLP_CLASS_PARTIAL_SPECIALIZATION

template <class _CharT, class _Traits, class _Alloc>
struct hash<basic_string<_CharT,_Traits,_Alloc> > {
  size_t operator()(const basic_string<_CharT,_Traits,_Alloc>& __s) const
    { return __stl_string_hash(__s); }
};

#else

_STLP_TEMPLATE_NULL struct _STLP_CLASS_DECLSPEC hash<string> {
  size_t operator()(const string& __s) const
    { return __stl_string_hash(__s); }
};

# if defined (_STLP_HAS_WCHAR_T)
_STLP_TEMPLATE_NULL struct _STLP_CLASS_DECLSPEC hash<wstring> {
  size_t operator()(const wstring& __s) const
    { return __stl_string_hash(__s); }
};
# endif

#endif /* _STLP_CLASS_PARTIAL_SPECIALIZATION */

_STLP_END_NAMESPACE

#endif