libcxx/test/std/localization/locales/locale.convenience/conversions/conversions.buffer/seekoff.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 // <locale>
  10
  11 // ADDITIONAL_COMPILE_FLAGS: -D_LIBCPP_DISABLE_DEPRECATION_WARNINGS -D_LIBCPP_ENABLE_CXX26_REMOVED_WSTRING_CONVERT
  12
  13 // wbuffer_convert<Codecvt, Elem, Tr>
  14
  15 // pos_type seekoff(off_type off, ios_base::seekdir way,
  16 //                  ios_base::openmode which = ios_base::in | ios_base::out);
  17 // pos_type seekpos(pos_type sp,
  18 //                  ios_base::openmode which = ios_base::in | ios_base::out);
  19
  20 // This test is not entirely portable
  21
  22 // XFAIL: no-wide-characters
  23
  24 // TODO: Avoid using <fstream> in this test.
  25 // XFAIL: no-filesystem
  26
  27 #include <locale>
  28 #include <codecvt>
  29 #include <fstream>
  30 #include <cassert>
  31
  32 class test_codecvt
  33     : public std::codecvt<wchar_t, char, std::mbstate_t>
  34 {
  35     typedef std::codecvt<wchar_t, char, std::mbstate_t> base;
  36 public:
  37     explicit test_codecvt(std::size_t refs = 0) : base(refs) {}
  38     ~test_codecvt() {}
  39 };
  40
  41 int main(int, char**)
  42 {
  43     {
  44         wchar_t buf[10];
  45         typedef std::wbuffer_convert<test_codecvt> test_buf;
  46         typedef test_buf::pos_type pos_type;
  47         std::fstream bs("seekoff.dat", std::ios::trunc | std::ios::in
  48                                                        | std::ios::out);
  49         test_buf f(bs.rdbuf());
  50         f.pubsetbuf(buf, sizeof(buf)/sizeof(buf[0]));
  51         f.sputn(L"abcdefghijklmnopqrstuvwxyz", 26);
  52         assert(buf[0] == L'v');
  53         pos_type p = f.pubseekoff(-15, std::ios_base::cur);
  54         assert(p == 11);
  55         assert(f.sgetc() == L'l');
  56         f.pubseekoff(0, std::ios_base::beg);
  57         assert(f.sgetc() == L'a');
  58         f.pubseekoff(-1, std::ios_base::end);
  59         assert(f.sgetc() == L'z');
  60         assert(f.pubseekpos(p) == p);
  61         assert(f.sgetc() == L'l');
  62     }
  63     std::remove("seekoff.dat");
  64
  65   return 0;
  66 }