libstdc++-v3/testsuite/27_io/basic_istream/ignore/char/2.cc

   1 // Copyright (C) 2004-2020 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 // 27.6.1.3 unformatted input functions
  19
  20 // { dg-require-fileio "" }
  21
  22 #include <istream>
  23 #include <string>
  24 #include <fstream>
  25 #include <limits>
  26 #include <cstdlib>
  27 #include <testsuite_hooks.h>
  28
  29 using namespace std;
  30
  31 string prepare(string::size_type len, unsigned nchunks, char delim)
  32 {
  33   string ret;
  34   for (unsigned i = 0; i < nchunks; ++i)
  35     {
  36       for (string::size_type j = 0; j < len; ++j)
  37         ret.push_back('a' + rand() % 26);
  38       len *= 2;
  39       ret.push_back(delim);
  40     }
  41   return ret;
  42 }
  43
  44 void check(istream& stream, const string& str, unsigned nchunks, char delim)
  45 {
  46   string::size_type index = 0, index_new = 0;
  47   unsigned n = 0;
  48
  49   while (stream.ignore(numeric_limits<streamsize>::max(), delim).good())
  50     {
  51       index_new = str.find(delim, index);
  52       VERIFY( static_cast<string::size_type>(stream.gcount()) ==
  53               index_new - index + 1 );
  54       index = index_new + 1;
  55       ++n;
  56     }
  57   VERIFY( stream.gcount() == 0 );
  58   VERIFY( !stream.fail() );
  59   VERIFY( n == nchunks );
  60 }
  61
  62 void test01()
  63 {
  64   const char filename[] = "istream_ignore.txt";
  65
  66   const char delim = '|';
  67   const unsigned nchunks = 10;
  68   const string data = prepare(555, nchunks, delim);
  69
  70   ofstream ofstrm;
  71   ofstrm.open(filename);
  72   ofstrm.write(data.data(), data.size());
  73   ofstrm.close();
  74
  75   ifstream ifstrm;
  76   ifstrm.open(filename);
  77   check(ifstrm, data, nchunks, delim);
  78   ifstrm.close();
  79 }
  80
  81 int main()
  82 {
  83   test01();
  84   return 0;
  85 }