istream.tcc (ignore): Correctly deal with n == numeric_limits<streamsize>::max().

[thirdparty/gcc.git] / libstdc++-v3 / testsuite / 27_io / basic_istream / ignore / char / 2.cc

// Copyright (C) 2004 Free Software Foundation
//
// 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.

// 27.6.1.3 unformatted input functions

#include <istream>
#include <string>
#include <fstream>
#include <limits>
#include <testsuite_hooks.h>

using namespace std;

string prepare(string::size_type len, unsigned nchunks, char delim)
{
  string ret;
  for (unsigned i = 0; i < nchunks; ++i)
    {
      for (string::size_type j = 0; j < len; ++j)
	ret.push_back('a' + rand() % 26);
      len *= 2;
      ret.push_back(delim);
    }
  return ret;
}

void check(istream& stream, const string& str, unsigned nchunks, char delim)
{
  bool test __attribute__((unused)) = true;

  string::size_type index = 0, index_new = 0;
  unsigned n = 0;

  while (stream.ignore(numeric_limits<streamsize>::max(), delim).good())
    {
      index_new = str.find(delim, index);
      VERIFY( stream.gcount() == index_new - index + 1 );
      index = index_new + 1;
      ++n;
    }
  VERIFY( stream.gcount() == 0 );
  VERIFY( !stream.fail() );
  VERIFY( n == nchunks );
}

void test01()
{
  const char filename[] = "istream_ignore.txt";

  const char delim = '|';
  const unsigned nchunks = 10;
  const string data = prepare(555, nchunks, delim);

  ofstream ofstrm;
  ofstrm.open(filename);
  ofstrm.write(data.data(), data.size());
  ofstrm.close();

  ifstream ifstrm;
  ifstrm.open(filename);
  check(ifstrm, data, nchunks, delim);
  ifstrm.close();
}

int main()
{
  test01();
  return 0;
}