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Mac OS X 10.4.9 for x86 Source Code gcc 实现源代码

// 2001-05-21 Benjamin Kosnik  <[e-mail]>

// Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 2, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING.  If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.

// 27.8.1.4 Overridden virtual functions

#include <fstream>
#include <testsuite_hooks.h>

// @require@ %-*.tst %-*.txt
// @diff@ %-*.tst %*.txt

// NB: This test assumes that _M_buf_size == 40, and not the usual
// buffer_size length of BUFSIZ (8192), so that overflow/underflow can be
// simulated a bit more readily.
// NRB (Nota Really Bene): setting it to 40 breaks the test, as intended.
const int buffer_size = 8192;
//const int buffer_size = 40;

const char name_01[] = "filebuf_virtuals-1.txt"; // file with data in it
const char name_02[] = "filebuf_virtuals-2.txt"; // empty file, need to create
const char name_03[] = "filebuf_virtuals-3.txt"; // empty file, need to create

class derived_filebuf: public std::filebuf
{
 public:
  void
  set_size(int_type __size) { _M_buf_size = __size; }
};

derived_filebuf fb_01; // in 
derived_filebuf fb_02; // out
derived_filebuf fb_03; // in | out

// Initialize filebufs to be the same size regardless of platform.
void test03()
{
  fb_01.set_size(buffer_size);
  fb_02.set_size(buffer_size);
  fb_03.set_size(buffer_size);
}

// Test overloaded virtual functions.
void test05() 
{
  typedef std::filebuf::int_type 	int_type;
  typedef std::filebuf::traits_type 	traits_type;
  typedef std::filebuf::pos_type 	pos_type;
  typedef std::filebuf::off_type 	off_type;
  typedef size_t 			size_type;

  bool test __attribute__((unused)) = true;
  std::filebuf 				f_tmp;
  std::streamoff  			strmof_1, strmof_2;

  // GET
  // int in_avail()
  // if a read position is available, return _M_in_end - _M_in_cur.
  // else return showmanyc.
  strmof_1 = fb_01.in_avail();
  strmof_2 = fb_02.in_avail();
  VERIFY( strmof_1 == -1 );
  VERIFY( strmof_1 == strmof_2 ); //fail because not open
  strmof_1 = fb_03.in_avail();
  VERIFY( strmof_1 == strmof_2 );
  fb_01.open(name_01, std::ios_base::in);
  fb_02.open(name_02, std::ios_base::out | std::ios_base::trunc);
  fb_03.open(name_03, std::ios_base::out | std::ios_base::in | std::ios_base::trunc); 
  strmof_1 = fb_01.in_avail();
  strmof_2 = fb_02.in_avail();
  VERIFY( strmof_1 != strmof_2 );
  VERIFY( strmof_1 >= 0 );
  VERIFY( strmof_2 == -1 );  // empty file
  strmof_1 = fb_03.in_avail(); 
  VERIFY( strmof_1  == 0 ); // empty file
}

int main() 
{
  test03();
  test05();
  return 0;
}