libstdc++-v3/testsuite/27_io/basic_fstream/assign/1.cc

// Copyright (C) 2014-2026 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 3, 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 COPYING3.  If not see
// <http://www.gnu.org/licenses/>.

// { dg-do run { target c++11 } }
// { dg-require-fileio "" }

// 27.9.1.16 Assign and swap [fstream.assign]

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

using namespace std;

string const name = "fstream-assign.txt";

void
test01()
{
  string orig = "Let the whole outside world consist of a long paper tape.";
  {
    fstream f(name, ios::in|ios::out|ios::trunc);
    VERIFY( f.is_open() );
    f << orig;
    fstream f1;
    f1 = std::move(f);
    VERIFY( f1.is_open() );
    VERIFY( !f.is_open() );
    f1.seekg(0);
    string result;
    getline(f1, result);
    VERIFY( result == orig );
  }
  {
    fstream f(name, ios::in);
    VERIFY( f.is_open() );
    fstream f1;
    f1.swap(f);
    VERIFY( f1.is_open() );
    VERIFY( !f.is_open() );
    string result;
    getline(f1, result);
    VERIFY( result == orig );
  }
  {
    fstream f(name, ios::in);
    VERIFY( f.is_open() );
    fstream f1;
    swap(f1, f);
    VERIFY( f1.is_open() );
    VERIFY( !f.is_open() );
    string result;
    getline(f1, result);
    VERIFY( result == orig );
  }
}

void
test02()
{
#ifdef _GLIBCXX_USE_WCHAR_T
  wfstream f, f2;
  f2 = std::move(f);
  f2.swap(f);
  swap(f2, f);
#endif
}

int
main()
{
  test01();
  test02();
}