libstdc++-v3/src/hash.cc

   1 //  std::hash and std::tr1::hash definitions -*- C++ -*-
   2
   3 // Copyright (C) 2007 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 2, 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 // You should have received a copy of the GNU General Public License
  17 // along with this library; see the file COPYING.  If not, write to
  18 // the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  19 // Boston, MA 02110-1301, USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 #include <cstddef>
  31 #include <string>
  32
  33 #ifdef __GXX_EXPERIMENTAL_CXX0X__
  34 #include <functional>
  35 #  define _GLIBCXX_BEGIN_NAMESPACE_TR1
  36 #  define _GLIBCXX_END_NAMESPACE_TR1
  37 #else
  38 #include <tr1/functional>
  39 #  define _GLIBCXX_INCLUDE_AS_TR1
  40 #  define _GLIBCXX_BEGIN_NAMESPACE_TR1 namespace tr1 {
  41 #  define _GLIBCXX_END_NAMESPACE_TR1 }
  42 #endif
  43
  44 namespace std
  45 {
  46 _GLIBCXX_BEGIN_NAMESPACE_TR1
  47
  48   template<>
  49     size_t
  50     hash<string>::operator()(string __s) const
  51     { return _Fnv_hash<>::hash(__s.data(), __s.length()); }
  52
  53   template<>
  54     size_t
  55     hash<const string&>::operator()(const string& __s) const
  56     { return _Fnv_hash<>::hash(__s.data(), __s.length()); }
  57
  58 #ifdef _GLIBCXX_USE_WCHAR_T
  59   template<>
  60     size_t
  61     hash<wstring>::operator()(wstring __s) const
  62     {
  63       const char* __p = reinterpret_cast<const char*>(__s.data());
  64       return _Fnv_hash<>::hash(__p, __s.length() * sizeof(wchar_t));
  65     }
  66
  67   template<>
  68     size_t
  69     hash<const wstring&>::operator()(const wstring& __s) const
  70     {
  71       const char* __p = reinterpret_cast<const char*>(__s.data());
  72       return _Fnv_hash<>::hash(__p, __s.length() * sizeof(wchar_t));
  73     }
  74 #endif
  75
  76 _GLIBCXX_END_NAMESPACE_TR1
  77 }