gcc/libstdc++-v3/testsuite/27_io/istream_seeks.cc

// 2000-06-29 bkoz

// Copyright (C) 2000 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
// NB: ostream has a particular "seeks" category. Adopt this for istreams too.

#include <istream>
#include <sstream>
#include <fstream>
#include <debug_assert.h>


bool test01()
{
  using namespace std;
  typedef ios::pos_type pos_type;

  bool test = true;
  const char str_lit01[] = "istream_unformatted-1.tst";

  // in
  // test default ctors leave things in the same positions...
  istringstream ist1;
  pos_type p3 = ist1.tellg();

  ifstream ifs1;
  pos_type p4 = ifs1.tellg();

  VERIFY( p3 == p4 );

  // in
  // test ctors leave things in the same positions...
  istringstream ist2("bob_marley:kaya");
  p3 = ist2.tellg();

  ifstream ifs2(str_lit01);
  p4 = ifs2.tellg();

  VERIFY( p3 == p4 );

#ifdef DEBUG_ASSERT
  assert(test);
#endif

  return test;
}

// fstreams
void test04(void)
{
  bool test = true;
  std::istream::pos_type pos01, pos02, pos03, pos04, pos05, pos06;
  std::ios_base::iostate state01, state02;
  const char str_lit01[] = "istream_unformatted-1.txt";
  const char str_lit02[] = "istream_unformatted-2.txt";
  std::ifstream if01(str_lit01, std::ios_base::in | std::ios_base::out);
  std::ifstream if02(str_lit01, std::ios_base::in);
  std::ifstream if03(str_lit02, std::ios_base::out | std::ios_base::trunc); 
  VERIFY( if01.good() );
  VERIFY( if02.good() );
  VERIFY( if03.good() );

  std::istream is01(if01.rdbuf());
  std::istream is02(if02.rdbuf());
  std::istream is03(if03.rdbuf());

  // pos_type tellg()
  // in | out
  pos01 = is01.tellg();
  pos02 = is01.tellg();
  VERIFY( pos01 == pos02 );
  //  VERIFY( istream::pos_type(0) != pos01 ); //deprecated

  // in
  pos03 = is02.tellg();
  pos04 = is02.tellg();
  VERIFY( pos03 == pos04 );
  //  VERIFY( istream::pos_type(0) != pos03 ); //deprecated

  // out
  pos05 = is03.tellg();
  pos06 = is03.tellg();
  VERIFY( pos05 == pos06 );
  //  VERIFY( istream::pos_type(0) != pos01 ); //deprecated

  // istream& seekg(pos_type)
  // istream& seekg(off_type, ios_base::seekdir)

  // cur 
  // NB: see library issues list 136. It's the v-3 interp that seekg
  // only sets the input buffer, or else istreams with buffers that
  // have _M_mode == ios_base::out will fail to have consistency
  // between seekg and tellg.
  state01 = is01.rdstate();
  is01.seekg(10, std::ios_base::cur);
  state02 = is01.rdstate();
  pos01 = is01.tellg(); 
  VERIFY( pos01 == pos02 + 10 ); 
  VERIFY( state01 == state02 );
  pos02 = is01.tellg(); 
  VERIFY( pos02 == pos01 ); 

  state01 = is02.rdstate();
  is02.seekg(10, std::ios_base::cur);
  state02 = is02.rdstate();
  pos03 = is02.tellg(); 
  VERIFY( pos03 == pos04 + 10 ); 
  VERIFY( state01 == state02 );
  pos04 = is02.tellg(); 
  VERIFY( pos03 == pos04 ); 

  state01 = is03.rdstate();
  is03.seekg(10, std::ios_base::cur);
  state02 = is03.rdstate();
  pos05 = is03.tellg(); 
  VERIFY( pos05 == pos06 + 10 ); 
  VERIFY( state01 == state02 );
  pos06 = is03.tellg(); 
  VERIFY( pos05 == pos06 ); 

  // beg
  state01 = is01.rdstate();
  is01.seekg(20, std::ios_base::beg);
  state02 = is01.rdstate();
  pos01 = is01.tellg(); 
  VERIFY( pos01 == pos02 + 10 ); 
  VERIFY( state01 == state02 );
  pos02 = is01.tellg(); 
  VERIFY( pos02 == pos01 ); 

  state01 = is02.rdstate();
  is02.seekg(20, std::ios_base::beg);
  state02 = is02.rdstate();
  pos03 = is02.tellg(); 
  VERIFY( pos03 == pos04 + 10 ); 
  VERIFY( state01 == state02 );
  pos04 = is02.tellg(); 
  VERIFY( pos03 == pos04 ); 

  state01 = is03.rdstate();
  is03.seekg(20, std::ios_base::beg);
  state02 = is03.rdstate();
  pos05 = is03.tellg(); 
  VERIFY( pos05 == pos06 + 10 );
  VERIFY( state01 == state02 );
  pos06 = is03.tellg(); 
  VERIFY( pos05 == pos06 ); 

#ifdef DEBUG_ASSERT
  assert(test);
#endif
}

// stringstreams
void test05(void)
{
  bool test = true;
  std::istream::pos_type pos01, pos02, pos03, pos04, pos05, pos06;
  std::ios_base::iostate state01, state02;
  const char str_lit01[] = "istream_unformatted-1.tst";
  std::ifstream if01(str_lit01);
  std::ifstream if02(str_lit01);
  std::ifstream if03(str_lit01);
  VERIFY( if01.good() );
  VERIFY( if02.good() );
  VERIFY( if03.good() );

  std::stringbuf strbuf01(std::ios_base::in | std::ios_base::out);
  if01 >> &strbuf01; 
  // initialize stringbufs that are ios_base::out
  std::stringbuf strbuf03(strbuf01.str(), std::ios_base::out);
  // initialize stringbufs that are ios_base::in
  std::stringbuf strbuf02(strbuf01.str(), std::ios_base::in);

  std::istream is01(&strbuf01);
  std::istream is02(&strbuf02);
  std::istream is03(&strbuf03);

  // pos_type tellg()
  // in | out
  pos01 = is01.tellg();
  pos02 = is01.tellg();
  VERIFY( pos01 == pos02 );
  // VERIFY( istream::pos_type(0) != pos01 ); // deprecated

  // in
  pos03 = is02.tellg();
  pos04 = is02.tellg();
  VERIFY( pos03 == pos04 );
  //  VERIFY( istream::pos_type(0) != pos03 ); // deprecated

  // out
  pos05 = is03.tellg();
  pos06 = is03.tellg();
  VERIFY( pos05 == pos06 );
  //  VERIFY( istream::pos_type(0) != pos01 ); //deprecated

  // istream& seekg(pos_type)
  // istream& seekg(off_type, ios_base::seekdir)

  // cur 
  // NB: see library issues list 136. It's the v-3 interp that seekg
  // only sets the input buffer, or else istreams with buffers that
  // have _M_mode == ios_base::out will fail to have consistency
  // between seekg and tellg.
  state01 = is01.rdstate();
  is01.seekg(10, std::ios_base::cur);
  state02 = is01.rdstate();
  pos01 = is01.tellg(); 
  VERIFY( pos01 == pos02 + 10 ); 
  VERIFY( state01 == state02 );
  pos02 = is01.tellg(); 
  VERIFY( pos02 == pos01 ); 

  state01 = is02.rdstate();
  is02.seekg(10, std::ios_base::cur);
  state02 = is02.rdstate();
  pos03 = is02.tellg(); 
  VERIFY( pos03 == pos04 + 10 ); 
  VERIFY( state01 == state02 );
  pos04 = is02.tellg(); 
  VERIFY( pos03 == pos04 ); 

  state01 = is03.rdstate();
  is03.seekg(10, std::ios_base::cur);
  state02 = is03.rdstate();
  pos05 = is03.tellg(); 
  VERIFY( pos05 == pos06 ); // as only out buffer 
  VERIFY( state01 == state02 );
  pos06 = is03.tellg(); 
  VERIFY( pos05 == pos06 ); 

  // beg
  state01 = is01.rdstate();
  is01.seekg(20, std::ios_base::beg);
  state02 = is01.rdstate();
  pos01 = is01.tellg(); 
  VERIFY( pos01 == pos02 + 10 ); 
  VERIFY( state01 == state02 );
  pos02 = is01.tellg(); 
  VERIFY( pos02 == pos01 ); 

  state01 = is02.rdstate();
  is02.seekg(20, std::ios_base::beg);
  state02 = is02.rdstate();
  pos03 = is02.tellg(); 
  VERIFY( pos03 == pos04 + 10 ); 
  VERIFY( state01 == state02 );
  pos04 = is02.tellg(); 
  VERIFY( pos03 == pos04 ); 

  state01 = is03.rdstate();
  is03.seekg(20, std::ios_base::beg);
  state02 = is03.rdstate();
  pos05 = is03.tellg(); 
  VERIFY( pos05 == pos06 ); // as only out buffer 
  VERIFY( state01 == state02 );
  pos06 = is03.tellg(); 
  VERIFY( pos05 == pos06 ); 

#ifdef DEBUG_ASSERT
  assert(test);
#endif
}

int main()
{
  test01();
  test04();
  test05();
  return 0;
}