libstdc++-v3/testsuite/27_io/basic_filebuf/in_avail/char/1.cc

   1 // 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
   2
   3 // Copyright (C) 2001, 2002, 2003 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 along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  19 // USA.
  20
  21 // 27.8.1.4 Overridden virtual functions
  22
  23 #include <fstream>
  24 #include <testsuite_hooks.h>
  25
  26 // @require@ %-*.tst %-*.txt
  27 // @diff@ %-*.tst %*.txt
  28
  29 // NB: This test assumes that _M_buf_size == 40, and not the usual
  30 // buffer_size length of BUFSIZ (8192), so that overflow/underflow can be
  31 // simulated a bit more readily.
  32 // NRB (Nota Really Bene): setting it to 40 breaks the test, as intended.
  33 const int buffer_size = 8192;
  34 //const int buffer_size = 40;
  35
  36 const char name_01[] = "filebuf_virtuals-1.txt"; // file with data in it
  37 const char name_02[] = "filebuf_virtuals-2.txt"; // empty file, need to create
  38 const char name_03[] = "filebuf_virtuals-3.txt"; // empty file, need to create
  39
  40 class derived_filebuf: public std::filebuf
  41 {
  42  public:
  43   void
  44   set_size(int_type __size) { _M_buf_size = __size; }
  45 };
  46
  47 derived_filebuf fb_01; // in
  48 derived_filebuf fb_02; // out
  49 derived_filebuf fb_03; // in | out
  50
  51 // Initialize filebufs to be the same size regardless of platform.
  52 void test03()
  53 {
  54   fb_01.set_size(buffer_size);
  55   fb_02.set_size(buffer_size);
  56   fb_03.set_size(buffer_size);
  57 }
  58
  59 // Test overloaded virtual functions.
  60 void test05()
  61 {
  62   typedef std::filebuf::int_type        int_type;
  63   typedef std::filebuf::traits_type     traits_type;
  64   typedef std::filebuf::pos_type        pos_type;
  65   typedef std::filebuf::off_type        off_type;
  66   typedef size_t                        size_type;
  67
  68   bool test __attribute__((unused)) = true;
  69   std::filebuf                          f_tmp;
  70   std::streamoff                        strmof_1, strmof_2;
  71
  72   // GET
  73   // int in_avail()
  74   // if a read position is available, return _M_in_end - _M_in_cur.
  75   // else return showmanyc.
  76   strmof_1 = fb_01.in_avail();
  77   strmof_2 = fb_02.in_avail();
  78   VERIFY( strmof_1 == -1 );
  79   VERIFY( strmof_1 == strmof_2 ); //fail because not open
  80   strmof_1 = fb_03.in_avail();
  81   VERIFY( strmof_1 == strmof_2 );
  82   fb_01.open(name_01, std::ios_base::in);
  83   fb_02.open(name_02, std::ios_base::out | std::ios_base::trunc);
  84   fb_03.open(name_03, std::ios_base::out | std::ios_base::in | std::ios_base::trunc);
  85   strmof_1 = fb_01.in_avail();
  86   strmof_2 = fb_02.in_avail();
  87   VERIFY( strmof_1 != strmof_2 );
  88   VERIFY( strmof_1 >= 0 );
  89   VERIFY( strmof_2 == -1 );  // empty file
  90   strmof_1 = fb_03.in_avail();
  91   VERIFY( strmof_1  == 0 ); // empty file
  92 }
  93
  94 int main()
  95 {
  96   test03();
  97   test05();
  98   return 0;
  99 }