libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/wchar_t/9875_seekoff.cc

   1 // Copyright (C) 2003 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 2, 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 COPYING.  If not, write to the Free
  16 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  17 // USA.
  18
  19 // 27.8.1.4 Overridden virtual functions
  20
  21 #include <fstream>
  22 #include <locale>
  23 #include <algorithm>
  24 #include <cstring>
  25 #include <testsuite_hooks.h>
  26
  27 class Cvt : public std::codecvt<wchar_t, char, mbstate_t>
  28 {
  29 protected:
  30   virtual std::codecvt_base::result
  31   do_out(std::mbstate_t&, const wchar_t* from, const wchar_t* from_end,
  32          const wchar_t*& from_next, char* to, char* to_end,
  33          char*& to_next) const
  34   {
  35     std::size_t from_len = from_end - from;
  36     std::size_t to_len = (to_end - to) / sizeof(wchar_t);
  37     std::size_t len = std::min(from_len, to_len);
  38     std::memcpy(to, from, len * sizeof(wchar_t));
  39     from_next = from + len;
  40     to_next = to + len * sizeof(wchar_t);
  41     return from_next == from_end ? std::codecvt_base::ok :
  42            std::codecvt_base::partial;
  43   }
  44
  45   virtual std::codecvt_base::result
  46   do_in(std::mbstate_t&, const char* from, const char* from_end,
  47         const char*& from_next, wchar_t* to, wchar_t* to_end,
  48         wchar_t*& to_next) const
  49   {
  50     std::size_t from_len =
  51       (from_end - from) / sizeof(wchar_t);
  52     std::size_t to_len = to_end - to;
  53     std::size_t len = std::min(from_len, to_len);
  54     std::memcpy(to, from, len * sizeof(wchar_t));
  55     from_next = from + len * sizeof(wchar_t);
  56     to_next = to + len;
  57     return from_next == from_end ? std::codecvt_base::ok :
  58            std::codecvt_base::partial;
  59   }
  60
  61   virtual std::codecvt_base::result
  62   do_unshift(std::mbstate_t&, char*, char*, char*&) const
  63   { return std::codecvt_base::noconv; }
  64
  65   virtual int do_encoding() const throw() { return sizeof(wchar_t); }
  66   virtual bool do_always_noconv() const throw() { return false; }
  67
  68   virtual int
  69   do_length(std::mbstate_t&, const char* from, const char* end,
  70             std::size_t max)
  71   {
  72     std::size_t len = (end - from) / sizeof(wchar_t);
  73     return std::min(len, max) * sizeof(wchar_t);
  74   }
  75
  76   virtual int do_max_length() const throw() { return sizeof(wchar_t); }
  77 };
  78
  79 void test01()
  80 {
  81   using namespace std;
  82   bool test __attribute__((unused)) = true;
  83
  84   // seekoff
  85   wfilebuf fb;
  86   fb.pubimbue(locale(locale::classic(), new Cvt));
  87   fb.open("tmp_9875_seekoff", ios_base::out | ios_base::in | ios_base::trunc);
  88   fb.sputn(L"0123456789", 10);
  89   fb.pubseekoff(-3, ios_base::cur);
  90   VERIFY( fb.sgetc() == L'7' );
  91   fb.pubseekoff(-3, ios_base::cur);
  92   VERIFY( fb.sgetc() == L'4' );
  93   fb.close();
  94 }
  95
  96 int main()
  97 {
  98   test01();
  99   return 0;
 100 }