libcxx/test/std/input.output/file.streams/fstreams/filebuf.assign/nonmember_swap_min.pass.cpp

   1 //===----------------------------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 // This tests that swapping filebufs works correctly even when the small buffer
  10 // optimization is in use (https://github.com/llvm/llvm-project/issues/49282).
  11
  12 // <fstream>
  13
  14 // template <class charT, class traits = char_traits<charT> >
  15 // class basic_filebuf
  16
  17 // template <class charT, class traits>
  18 // void
  19 // swap(basic_filebuf<charT, traits>& x, basic_filebuf<charT, traits>& y);
  20
  21 #include <fstream>
  22 #include <cassert>
  23 #include "test_macros.h"
  24 #include "platform_support.h"
  25
  26 int main(int, char**)
  27 {
  28     std::string tmpA = get_temp_file_name();
  29     std::string tmpB = get_temp_file_name();
  30
  31     {
  32         std::ofstream sa(tmpA), sb(tmpB);
  33         sa << "AAAA";
  34         sb << "BBBB";
  35     }
  36
  37     std::filebuf f1;
  38     assert(f1.open(tmpA, std::ios_base::in) != 0);
  39     assert(f1.is_open());
  40     f1.pubsetbuf(0, 0);
  41
  42     std::filebuf f2;
  43     assert(f2.open(tmpB, std::ios_base::in) != 0);
  44     assert(f2.is_open());
  45     f2.pubsetbuf(0, 0);
  46
  47     assert(f1.sgetc() == 'A');
  48     assert(f2.sgetc() == 'B');
  49
  50     swap(f1, f2);
  51
  52     assert(f1.is_open());
  53     assert(f2.is_open());
  54
  55     assert(f1.sgetc() == 'B');
  56     assert(f2.sgetc() == 'A');
  57
  58     std::remove(tmpA.c_str());
  59     std::remove(tmpB.c_str());
  60
  61     return 0;
  62 }