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

   1 // Copyright (C) 2003-2013 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 #include <fstream>
  21 #include <locale>
  22 #include <algorithm>
  23 #include <cstring>
  24 #include <testsuite_hooks.h>
  25
  26 class Cvt : public std::codecvt<wchar_t, char, mbstate_t>
  27 {
  28 protected:
  29   virtual std::codecvt_base::result
  30   do_out(std::mbstate_t&, const wchar_t* from, const wchar_t* from_end,
  31          const wchar_t*& from_next, char* to, char* to_end,
  32          char*& to_next) const
  33   {
  34     std::size_t from_len = from_end - from;
  35     std::size_t to_len = (to_end - to) / sizeof(wchar_t);
  36     std::size_t len = std::min(from_len, to_len);
  37     std::memcpy(to, from, len * sizeof(wchar_t));
  38     from_next = from + len;
  39     to_next = to + len * sizeof(wchar_t);
  40     return from_next == from_end ? std::codecvt_base::ok :
  41            std::codecvt_base::partial;
  42   }
  43
  44   virtual std::codecvt_base::result
  45   do_in(std::mbstate_t&, const char* from, const char* from_end,
  46         const char*& from_next, wchar_t* to, wchar_t* to_end,
  47         wchar_t*& to_next) const
  48   {
  49     std::size_t from_len =
  50       (from_end - from) / sizeof(wchar_t);
  51     std::size_t to_len = to_end - to;
  52     std::size_t len = std::min(from_len, to_len);
  53     std::memcpy(to, from, len * sizeof(wchar_t));
  54     from_next = from + len * sizeof(wchar_t);
  55     to_next = to + len;
  56     return from_next == from_end ? std::codecvt_base::ok :
  57            std::codecvt_base::partial;
  58   }
  59
  60   virtual std::codecvt_base::result
  61   do_unshift(std::mbstate_t&, char*, char*, char*&) const
  62   { return std::codecvt_base::noconv; }
  63
  64   virtual int do_encoding() const throw() { return sizeof(wchar_t); }
  65   virtual bool do_always_noconv() const throw() { return false; }
  66
  67   virtual int
  68   do_length(std::mbstate_t&, const char* from, const char* end,
  69             std::size_t max)
  70   {
  71     std::size_t len = (end - from) / sizeof(wchar_t);
  72     return std::min(len, max) * sizeof(wchar_t);
  73   }
  74
  75   virtual int do_max_length() const throw() { return sizeof(wchar_t); }
  76 };
  77
  78 void test01()
  79 {
  80   using namespace std;
  81   bool test __attribute__((unused)) = true;
  82
  83   // seekoff
  84   wfilebuf fb;
  85   fb.pubimbue(locale(locale::classic(), new Cvt));
  86   fb.open("tmp_9875_seekoff", ios_base::out | ios_base::in | ios_base::trunc);
  87   fb.sputn(L"0123456789", 10);
  88   fb.pubseekoff(-3, ios_base::cur);
  89   VERIFY( fb.sgetc() == L'7' );
  90   fb.pubseekoff(-3, ios_base::cur);
  91   VERIFY( fb.sgetc() == L'4' );
  92   fb.close();
  93 }
  94
  95 int main()
  96 {
  97   test01();
  98   return 0;
  99 }