libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/11543.cc

   1 // Copyright (C) 2003-2024 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // 27.8.1.4 Overridden virtual functions
  19
  20 // { dg-require-fileio "" }
  21
  22 #include <fstream>
  23 #include <locale>
  24 #include <testsuite_hooks.h>
  25
  26 struct MyState
  27 {
  28 };
  29
  30 struct MyCharTraits : std::char_traits<char>
  31 {
  32   typedef std::fpos<MyState> pos_type;
  33   typedef MyState state_type;
  34 };
  35
  36 namespace std
  37 {
  38   template <>
  39     class codecvt<char, char, MyState> :
  40       public locale::facet, public codecvt_base
  41     {
  42     public:
  43       typedef char intern_type;
  44       typedef char extern_type;
  45       typedef MyState state_type;
  46
  47       explicit codecvt(size_t refs = 0)
  48       : locale::facet(refs) { }
  49
  50       result out(state_type& state, const intern_type* from,
  51                  const intern_type* from_end,  const intern_type*& from_next,
  52                  extern_type* to, extern_type* to_limit,
  53                  extern_type*& to_next) const
  54       { return do_out(state, from, from_end, from_next,
  55                       to, to_limit, to_next); }
  56
  57       result unshift(state_type& state, extern_type* to, extern_type* to_limit,
  58                      extern_type*& to_next) const
  59       { return do_unshift(state, to, to_limit, to_next); }
  60
  61       result in(state_type& state, const extern_type* from,
  62                 const extern_type* from_end, const extern_type*& from_next,
  63                 intern_type* to, intern_type* to_limit,
  64                 intern_type*& to_next) const
  65       { return do_in(state, from, from_end, from_next,
  66                      to, to_limit, to_next); }
  67
  68       int encoding() const throw()
  69       { return do_encoding(); }
  70
  71       bool always_noconv() const throw()
  72       { return do_always_noconv(); }
  73
  74       int length(state_type& state, const extern_type* from,
  75                  const extern_type* end, size_t max) const
  76       { return do_length(state, from, end, max); }
  77
  78       int max_length() const throw()
  79       { return do_max_length(); }
  80
  81       static locale::id id;
  82
  83     protected:
  84       virtual ~codecvt();
  85
  86       virtual result do_out(state_type&, const intern_type* from,
  87                             const intern_type*, const intern_type*& from_next,
  88                             extern_type* to, extern_type*,
  89                             extern_type*& to_next) const
  90       {
  91         from_next = from;
  92         to_next = to;
  93         return noconv;
  94       }
  95
  96       virtual result do_in(state_type&, const extern_type* from,
  97                            const extern_type*, const extern_type*& from_next,
  98                            intern_type* to, intern_type*,
  99                            intern_type*& to_next) const
 100       {
 101         from_next = from;
 102         to_next = to;
 103         return noconv;
 104       }
 105
 106       virtual result do_unshift(state_type&, extern_type*, extern_type*,
 107                                 extern_type*&) const
 108       { return noconv; }
 109
 110       virtual int do_encoding() const throw()
 111       { return 1; }
 112
 113       virtual bool do_always_noconv() const throw()
 114       { return true; }
 115
 116       virtual int do_length(state_type&, const extern_type* from,
 117                             const extern_type* end, size_t max) const
 118       {
 119         size_t len = end - from;
 120         return std::min(max, len);
 121       }
 122
 123       virtual int do_max_length() const throw()
 124       { return 1; }
 125     };
 126
 127   locale::id codecvt<char, char, MyState>::id;
 128
 129   codecvt<char, char, MyState>::~codecvt()
 130   { }
 131 }
 132
 133 void test01()
 134 {
 135   std::locale loc(std::locale::classic(),
 136                   new std::codecvt<char, char, MyState>);
 137   std::basic_filebuf<char, MyCharTraits> fb;
 138   fb.pubimbue(loc);
 139   fb.open("tmp_11543", std::ios_base::out);
 140   VERIFY( fb.is_open() );
 141   MyCharTraits::pos_type pos = fb.pubseekoff(0, std::ios_base::beg);
 142   VERIFY( pos != MyCharTraits::pos_type(MyCharTraits::off_type(-1)) );
 143   fb.close();
 144 }
 145
 146 int main()
 147 {
 148   test01();
 149   return 0;
 150 }