release/src-rt-6.x.4708/toolchains/hndtools-arm-linux-2.6.36-uclibc-4.5.3/arm-brcm-linux-uclibcgnueabi/include/c++/4.5.3/tr1/functional_hash.h

   1 // TR1 functional_hash.h header -*- C++ -*-
   2
   3 // Copyright (C) 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 /** @file tr1/functional_hash.h
  26  *  This is an internal header file, included by other library headers.
  27  *  You should not attempt to use it directly.
  28  */
  29
  30 #ifndef _GLIBCXX_TR1_FUNCTIONAL_HASH_H
  31 #define _GLIBCXX_TR1_FUNCTIONAL_HASH_H 1
  32
  33 #pragma GCC system_header
  34
  35 namespace std
  36 {
  37 namespace tr1
  38 {
  39   /// Class template hash.
  40   // Declaration of default hash functor std::tr1::hash.  The types for
  41   // which std::tr1::hash<T> is well-defined is in clause 6.3.3. of the PDTR.
  42   template<typename _Tp>
  43     struct hash : public std::unary_function<_Tp, size_t>
  44     {
  45       size_t
  46       operator()(_Tp __val) const;
  47     };
  48
  49   /// Partial specializations for pointer types.
  50   template<typename _Tp>
  51     struct hash<_Tp*> : public std::unary_function<_Tp*, size_t>
  52     {
  53       size_t
  54       operator()(_Tp* __p) const
  55       { return reinterpret_cast<size_t>(__p); }
  56     };
  57
  58   /// Explicit specializations for integer types.
  59 #define _TR1_hashtable_define_trivial_hash(_Tp)         \
  60   template<>                                            \
  61     inline size_t                                       \
  62     hash<_Tp>::operator()(_Tp __val) const              \
  63     { return static_cast<size_t>(__val); }
  64
  65   _TR1_hashtable_define_trivial_hash(bool);
  66   _TR1_hashtable_define_trivial_hash(char);
  67   _TR1_hashtable_define_trivial_hash(signed char);
  68   _TR1_hashtable_define_trivial_hash(unsigned char);
  69   _TR1_hashtable_define_trivial_hash(wchar_t);
  70   _TR1_hashtable_define_trivial_hash(short);
  71   _TR1_hashtable_define_trivial_hash(int);
  72   _TR1_hashtable_define_trivial_hash(long);
  73   _TR1_hashtable_define_trivial_hash(long long);
  74   _TR1_hashtable_define_trivial_hash(unsigned short);
  75   _TR1_hashtable_define_trivial_hash(unsigned int);
  76   _TR1_hashtable_define_trivial_hash(unsigned long);
  77   _TR1_hashtable_define_trivial_hash(unsigned long long);
  78
  79 #undef _TR1_hashtable_define_trivial_hash
  80
  81   // Fowler / Noll / Vo (FNV) Hash (type FNV-1a)
  82   // (Used by the next specializations of std::tr1::hash.)
  83
  84   /// Dummy generic implementation (for sizeof(size_t) != 4, 8).
  85   template<size_t>
  86     struct _Fnv_hash_base
  87     {
  88       template<typename _Tp>
  89         static size_t
  90         hash(const _Tp* __ptr, size_t __clength)
  91         {
  92           size_t __result = 0;
  93           const char* __cptr = reinterpret_cast<const char*>(__ptr);
  94           for (; __clength; --__clength)
  95             __result = (__result * 131) + *__cptr++;
  96           return __result;
  97         }
  98     };
  99
 100   template<>
 101     struct _Fnv_hash_base<4>
 102     {
 103       template<typename _Tp>
 104         static size_t
 105         hash(const _Tp* __ptr, size_t __clength)
 106         {
 107           size_t __result = static_cast<size_t>(2166136261UL);
 108           const char* __cptr = reinterpret_cast<const char*>(__ptr);
 109           for (; __clength; --__clength)
 110             {
 111               __result ^= static_cast<size_t>(*__cptr++);
 112               __result *= static_cast<size_t>(16777619UL);
 113             }
 114           return __result;
 115         }
 116     };
 117
 118   template<>
 119     struct _Fnv_hash_base<8>
 120     {
 121       template<typename _Tp>
 122         static size_t
 123         hash(const _Tp* __ptr, size_t __clength)
 124         {
 125           size_t __result
 126             = static_cast<size_t>(14695981039346656037ULL);
 127           const char* __cptr = reinterpret_cast<const char*>(__ptr);
 128           for (; __clength; --__clength)
 129             {
 130               __result ^= static_cast<size_t>(*__cptr++);
 131               __result *= static_cast<size_t>(1099511628211ULL);
 132             }
 133           return __result;
 134         }
 135     };
 136
 137   struct _Fnv_hash
 138   : public _Fnv_hash_base<sizeof(size_t)>
 139   {
 140     using _Fnv_hash_base<sizeof(size_t)>::hash;
 141
 142     template<typename _Tp>
 143       static size_t
 144       hash(const _Tp& __val)
 145       { return hash(&__val, sizeof(__val)); }
 146   };
 147
 148   /// Explicit specializations for float.
 149   template<>
 150     inline size_t
 151     hash<float>::operator()(float __val) const
 152     {
 153       // 0 and -0 both hash to zero.
 154       return __val != 0.0f ? std::tr1::_Fnv_hash::hash(__val) : 0;
 155     }
 156
 157   /// Explicit specializations for double.
 158   template<>
 159     inline size_t
 160     hash<double>::operator()(double __val) const
 161     {
 162       // 0 and -0 both hash to zero.
 163       return __val != 0.0 ? std::tr1::_Fnv_hash::hash(__val) : 0;
 164     }
 165
 166   /// Explicit specializations for long double.
 167   template<>
 168     _GLIBCXX_PURE size_t
 169     hash<long double>::operator()(long double __val) const;
 170
 171   /// Explicit specialization of member operator for non-builtin types.
 172   template<>
 173     _GLIBCXX_PURE size_t
 174     hash<string>::operator()(string) const;
 175
 176   template<>
 177     _GLIBCXX_PURE size_t
 178     hash<const string&>::operator()(const string&) const;
 179
 180 #ifdef _GLIBCXX_USE_WCHAR_T
 181   template<>
 182     _GLIBCXX_PURE size_t
 183     hash<wstring>::operator()(wstring) const;
 184
 185   template<>
 186     _GLIBCXX_PURE size_t
 187     hash<const wstring&>::operator()(const wstring&) const;
 188 #endif
 189 }
 190 }
 191
 192 #endif // _GLIBCXX_TR1_FUNCTIONAL_HASH_H