xref: /freebsd/contrib/llvm-project/libcxx/include/fstream (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_FSTREAM
11#define _LIBCPP_FSTREAM
12
13/*
14    fstream synopsis
15
16template <class charT, class traits = char_traits<charT> >
17class basic_filebuf
18    : public basic_streambuf<charT, traits>
19{
20public:
21    typedef charT                          char_type;
22    typedef traits                         traits_type;
23    typedef typename traits_type::int_type int_type;
24    typedef typename traits_type::pos_type pos_type;
25    typedef typename traits_type::off_type off_type;
26
27    // 27.9.1.2 Constructors/destructor:
28    basic_filebuf();
29    basic_filebuf(basic_filebuf&& rhs);
30    virtual ~basic_filebuf();
31
32    // 27.9.1.3 Assign/swap:
33    basic_filebuf& operator=(basic_filebuf&& rhs);
34    void swap(basic_filebuf& rhs);
35
36    // 27.9.1.4 Members:
37    bool is_open() const;
38    basic_filebuf* open(const char* s, ios_base::openmode mode);
39    basic_filebuf* open(const string& s, ios_base::openmode mode);
40    basic_filebuf* open(const filesystem::path& p, ios_base::openmode mode); // C++17
41    basic_filebuf* close();
42
43protected:
44    // 27.9.1.5 Overridden virtual functions:
45    virtual streamsize showmanyc();
46    virtual int_type underflow();
47    virtual int_type uflow();
48    virtual int_type pbackfail(int_type c = traits_type::eof());
49    virtual int_type overflow (int_type c = traits_type::eof());
50    virtual basic_streambuf<char_type, traits_type>* setbuf(char_type* s, streamsize n);
51    virtual pos_type seekoff(off_type off, ios_base::seekdir way,
52                             ios_base::openmode which = ios_base::in | ios_base::out);
53    virtual pos_type seekpos(pos_type sp,
54                             ios_base::openmode which = ios_base::in | ios_base::out);
55    virtual int sync();
56    virtual void imbue(const locale& loc);
57};
58
59template <class charT, class traits>
60  void
61  swap(basic_filebuf<charT, traits>& x, basic_filebuf<charT, traits>& y);
62
63typedef basic_filebuf<char>    filebuf;
64typedef basic_filebuf<wchar_t> wfilebuf;
65
66template <class charT, class traits = char_traits<charT> >
67class basic_ifstream
68    : public basic_istream<charT,traits>
69{
70public:
71    typedef charT                          char_type;
72    typedef traits                         traits_type;
73    typedef typename traits_type::int_type int_type;
74    typedef typename traits_type::pos_type pos_type;
75    typedef typename traits_type::off_type off_type;
76    using native_handle_type = typename basic_filebuf<charT, traits>::native_handle_type; // Since C++26
77
78    basic_ifstream();
79    explicit basic_ifstream(const char* s, ios_base::openmode mode = ios_base::in);
80    explicit basic_ifstream(const string& s, ios_base::openmode mode = ios_base::in);
81    template<class T>
82    explicit basic_ifstream(const T& s, ios_base::openmode mode = ios_base::in); // Since C++17
83    basic_ifstream(basic_ifstream&& rhs);
84
85    basic_ifstream& operator=(basic_ifstream&& rhs);
86    void swap(basic_ifstream& rhs);
87
88    basic_filebuf<char_type, traits_type>* rdbuf() const;
89    native_handle_type native_handle() const noexcept; // Since C++26
90    bool is_open() const;
91    void open(const char* s, ios_base::openmode mode = ios_base::in);
92    void open(const string& s, ios_base::openmode mode = ios_base::in);
93    void open(const filesystem::path& s, ios_base::openmode mode = ios_base::in); // C++17
94
95    void close();
96};
97
98template <class charT, class traits>
99  void
100  swap(basic_ifstream<charT, traits>& x, basic_ifstream<charT, traits>& y);
101
102typedef basic_ifstream<char>    ifstream;
103typedef basic_ifstream<wchar_t> wifstream;
104
105template <class charT, class traits = char_traits<charT> >
106class basic_ofstream
107    : public basic_ostream<charT,traits>
108{
109public:
110    typedef charT                          char_type;
111    typedef traits                         traits_type;
112    typedef typename traits_type::int_type int_type;
113    typedef typename traits_type::pos_type pos_type;
114    typedef typename traits_type::off_type off_type;
115    using native_handle_type = typename basic_filebuf<charT, traits>::native_handle_type; // Since C++26
116
117    basic_ofstream();
118    explicit basic_ofstream(const char* s, ios_base::openmode mode = ios_base::out);
119    explicit basic_ofstream(const string& s, ios_base::openmode mode = ios_base::out);
120    template<class T>
121    explicit basic_ofstream(const T& s, ios_base::openmode mode = ios_base::out); // Since C++17
122    basic_ofstream(basic_ofstream&& rhs);
123
124    basic_ofstream& operator=(basic_ofstream&& rhs);
125    void swap(basic_ofstream& rhs);
126
127    basic_filebuf<char_type, traits_type>* rdbuf() const;
128    native_handle_type native_handle() const noexcept; // Since C++26
129
130    bool is_open() const;
131    void open(const char* s, ios_base::openmode mode = ios_base::out);
132    void open(const string& s, ios_base::openmode mode = ios_base::out);
133    void open(const filesystem::path& p,
134              ios_base::openmode mode = ios_base::out); // C++17
135
136    void close();
137};
138
139template <class charT, class traits>
140  void
141  swap(basic_ofstream<charT, traits>& x, basic_ofstream<charT, traits>& y);
142
143typedef basic_ofstream<char>    ofstream;
144typedef basic_ofstream<wchar_t> wofstream;
145
146template <class charT, class traits=char_traits<charT> >
147class basic_fstream
148    : public basic_iostream<charT,traits>
149{
150public:
151    typedef charT                          char_type;
152    typedef traits                         traits_type;
153    typedef typename traits_type::int_type int_type;
154    typedef typename traits_type::pos_type pos_type;
155    typedef typename traits_type::off_type off_type;
156    using native_handle_type = typename basic_filebuf<charT, traits>::native_handle_type; // Since C++26
157
158    basic_fstream();
159    explicit basic_fstream(const char* s, ios_base::openmode mode = ios_base::in|ios_base::out);
160    explicit basic_fstream(const string& s, ios_base::openmode mode = ios_base::in|ios_base::out);
161    template<class T>
162    explicit basic_fstream(const T& s, ios_base::openmode mode = ios_base::in | ios_base::out); // Since C++17
163    basic_fstream(basic_fstream&& rhs);
164
165    basic_fstream& operator=(basic_fstream&& rhs);
166    void swap(basic_fstream& rhs);
167
168    basic_filebuf<char_type, traits_type>* rdbuf() const;
169    native_handle_type native_handle() const noexcept; // Since C++26
170    bool is_open() const;
171    void open(const char* s, ios_base::openmode mode = ios_base::in|ios_base::out);
172    void open(const string& s, ios_base::openmode mode = ios_base::in|ios_base::out);
173    void open(const filesystem::path& s,
174              ios_base::openmode mode = ios_base::in|ios_base::out); // C++17
175
176    void close();
177};
178
179template <class charT, class traits>
180  void swap(basic_fstream<charT, traits>& x, basic_fstream<charT, traits>& y);
181
182typedef basic_fstream<char>    fstream;
183typedef basic_fstream<wchar_t> wfstream;
184
185}  // std
186
187*/
188
189#include <__algorithm/max.h>
190#include <__assert>
191#include <__config>
192#include <__fwd/fstream.h>
193#include <__locale>
194#include <__type_traits/enable_if.h>
195#include <__type_traits/is_same.h>
196#include <__utility/move.h>
197#include <__utility/swap.h>
198#include <__utility/unreachable.h>
199#include <cstdio>
200#include <filesystem>
201#include <istream>
202#include <ostream>
203#include <typeinfo>
204#include <version>
205
206#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
207#  pragma GCC system_header
208#endif
209
210_LIBCPP_PUSH_MACROS
211#include <__undef_macros>
212
213#if defined(_LIBCPP_MSVCRT) || defined(_NEWLIB_VERSION)
214#  define _LIBCPP_HAS_NO_OFF_T_FUNCTIONS
215#endif
216
217#if !defined(_LIBCPP_HAS_NO_FILESYSTEM)
218
219_LIBCPP_BEGIN_NAMESPACE_STD
220
221#  if _LIBCPP_STD_VER >= 26 && defined(_LIBCPP_WIN32API)
222_LIBCPP_EXPORTED_FROM_ABI void* __filebuf_windows_native_handle(FILE* __file) noexcept;
223#  endif
224
225template <class _CharT, class _Traits>
226class _LIBCPP_TEMPLATE_VIS basic_filebuf : public basic_streambuf<_CharT, _Traits> {
227public:
228  typedef _CharT char_type;
229  typedef _Traits traits_type;
230  typedef typename traits_type::int_type int_type;
231  typedef typename traits_type::pos_type pos_type;
232  typedef typename traits_type::off_type off_type;
233  typedef typename traits_type::state_type state_type;
234#  if _LIBCPP_STD_VER >= 26
235#    if defined(_LIBCPP_WIN32API)
236  using native_handle_type = void*; // HANDLE
237#    elif __has_include(<unistd.h>)
238  using native_handle_type = int; // POSIX file descriptor
239#    else
240#      error "Provide a native file handle!"
241#    endif
242#  endif
243
244  // 27.9.1.2 Constructors/destructor:
245  basic_filebuf();
246  basic_filebuf(basic_filebuf&& __rhs);
247  ~basic_filebuf() override;
248
249  // 27.9.1.3 Assign/swap:
250  _LIBCPP_HIDE_FROM_ABI basic_filebuf& operator=(basic_filebuf&& __rhs);
251  void swap(basic_filebuf& __rhs);
252
253  // 27.9.1.4 Members:
254  _LIBCPP_HIDE_FROM_ABI bool is_open() const;
255  basic_filebuf* open(const char* __s, ios_base::openmode __mode);
256#  ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
257  basic_filebuf* open(const wchar_t* __s, ios_base::openmode __mode);
258#  endif
259  _LIBCPP_HIDE_FROM_ABI basic_filebuf* open(const string& __s, ios_base::openmode __mode);
260
261#  if _LIBCPP_STD_VER >= 17
262  _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY _LIBCPP_HIDE_FROM_ABI basic_filebuf*
263  open(const filesystem::path& __p, ios_base::openmode __mode) {
264    return open(__p.c_str(), __mode);
265  }
266#  endif
267  _LIBCPP_HIDE_FROM_ABI basic_filebuf* __open(int __fd, ios_base::openmode __mode);
268  basic_filebuf* close();
269#  if _LIBCPP_STD_VER >= 26
270  _LIBCPP_HIDE_FROM_ABI native_handle_type native_handle() const noexcept {
271    _LIBCPP_ASSERT_UNCATEGORIZED(this->is_open(), "File must be opened");
272#    if defined(_LIBCPP_WIN32API)
273    return std::__filebuf_windows_native_handle(__file_);
274#    elif __has_include(<unistd.h>)
275    return fileno(__file_);
276#    else
277#      error "Provide a way to determine the file native handle!"
278#    endif
279  }
280#  endif //  _LIBCPP_STD_VER >= 26
281
282  _LIBCPP_HIDE_FROM_ABI inline static const char* __make_mdstring(ios_base::openmode __mode) _NOEXCEPT;
283#  ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
284  _LIBCPP_HIDE_FROM_ABI inline static const wchar_t* __make_mdwstring(ios_base::openmode __mode) _NOEXCEPT;
285#  endif
286
287protected:
288  // 27.9.1.5 Overridden virtual functions:
289  int_type underflow() override;
290  int_type pbackfail(int_type __c = traits_type::eof()) override;
291  int_type overflow(int_type __c = traits_type::eof()) override;
292  basic_streambuf<char_type, traits_type>* setbuf(char_type* __s, streamsize __n) override;
293  pos_type
294  seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __wch = ios_base::in | ios_base::out) override;
295  pos_type seekpos(pos_type __sp, ios_base::openmode __wch = ios_base::in | ios_base::out) override;
296  int sync() override;
297  void imbue(const locale& __loc) override;
298
299private:
300  char* __extbuf_;
301  const char* __extbufnext_;
302  const char* __extbufend_;
303  char __extbuf_min_[8];
304  size_t __ebs_;
305  char_type* __intbuf_;
306  size_t __ibs_;
307  FILE* __file_;
308  const codecvt<char_type, char, state_type>* __cv_;
309  state_type __st_;
310  state_type __st_last_;
311  ios_base::openmode __om_;
312  // There have been no file operations yet, which allows setting unbuffered
313  // I/O mode.
314  static const ios_base::openmode __no_io_operations = ios_base::trunc;
315  // Unbuffered I/O mode has been requested.
316  static const ios_base::openmode __use_unbuffered_io = ios_base::ate;
317  // Used to track the currently used mode and track whether the output should
318  // be unbuffered.
319  // [filebuf.virtuals]/12
320  //   If setbuf(0, 0) is called on a stream before any I/O has occurred on
321  //   that stream, the stream becomes unbuffered. Otherwise the results are
322  //   implementation-defined.
323  // This allows calling setbuf(0, 0)
324  // - before opening a file,
325  // - after opening a file, before
326  //   - a read
327  //   - a write
328  //   - a seek.
329  // Note that opening a file with ios_base::ate does a seek operation.
330  // Normally underflow, overflow, and sync change this flag to ios_base::in,
331  // ios_base_out, or 0.
332  //
333  // The ios_base::trunc and ios_base::ate flags are not used in __cm_. They
334  // are used to track the state of the unbuffered request. For readability
335  // they have the aliases __no_io_operations and __use_unbuffered_io
336  // respectively.
337  //
338  // The __no_io_operations and __use_unbuffered_io flags are used in the
339  // following way:
340  // - __no_io_operations is set upon construction to indicate the unbuffered
341  //   state can be set.
342  // - When requesting unbuffered output:
343  //   - If the file is open it sets the mode.
344  //   - Else places a request by adding the __use_unbuffered_io flag.
345  // - When a file is opened it checks whether both __no_io_operations and
346  //   __use_unbuffered_io are set. If so switches to unbuffered mode.
347  // - All file I/O operations change the mode effectively clearing the
348  //   __no_io_operations and __use_unbuffered_io flags.
349  ios_base::openmode __cm_;
350  bool __owns_eb_;
351  bool __owns_ib_;
352  bool __always_noconv_;
353
354  bool __read_mode();
355  void __write_mode();
356
357  _LIBCPP_EXPORTED_FROM_ABI friend FILE* __get_ostream_file(ostream&);
358
359  // There are multiple (__)open function, they use different C-API open
360  // function. After that call these functions behave the same. This function
361  // does that part and determines the final return value.
362  _LIBCPP_HIDE_FROM_ABI basic_filebuf* __do_open(FILE* __file, ios_base::openmode __mode) {
363    __file_ = __file;
364    if (!__file_)
365      return nullptr;
366
367    __om_ = __mode;
368    if (__cm_ == (__no_io_operations | __use_unbuffered_io)) {
369      std::setbuf(__file_, nullptr);
370      __cm_ = 0;
371    }
372
373    if (__mode & ios_base::ate) {
374      __cm_ = 0;
375      if (fseek(__file_, 0, SEEK_END)) {
376        fclose(__file_);
377        __file_ = nullptr;
378        return nullptr;
379      }
380    }
381
382    return this;
383  }
384
385  // If the file is already open, switch to unbuffered mode. Otherwise, record
386  // the request to use unbuffered mode so that we use that mode when we
387  // eventually open the file.
388  _LIBCPP_HIDE_FROM_ABI void __request_unbuffered_mode(char_type* __s, streamsize __n) {
389    if (__cm_ == __no_io_operations && __s == nullptr && __n == 0) {
390      if (__file_) {
391        std::setbuf(__file_, nullptr);
392        __cm_ = 0;
393      } else {
394        __cm_ = __no_io_operations | __use_unbuffered_io;
395      }
396    }
397  }
398};
399
400template <class _CharT, class _Traits>
401basic_filebuf<_CharT, _Traits>::basic_filebuf()
402    : __extbuf_(nullptr),
403      __extbufnext_(nullptr),
404      __extbufend_(nullptr),
405      __ebs_(0),
406      __intbuf_(nullptr),
407      __ibs_(0),
408      __file_(nullptr),
409      __cv_(nullptr),
410      __st_(),
411      __st_last_(),
412      __om_(0),
413      __cm_(__no_io_operations),
414      __owns_eb_(false),
415      __owns_ib_(false),
416      __always_noconv_(false) {
417  if (std::has_facet<codecvt<char_type, char, state_type> >(this->getloc())) {
418    __cv_            = &std::use_facet<codecvt<char_type, char, state_type> >(this->getloc());
419    __always_noconv_ = __cv_->always_noconv();
420  }
421  setbuf(nullptr, 4096);
422}
423
424template <class _CharT, class _Traits>
425basic_filebuf<_CharT, _Traits>::basic_filebuf(basic_filebuf&& __rhs) : basic_streambuf<_CharT, _Traits>(__rhs) {
426  if (__rhs.__extbuf_ == __rhs.__extbuf_min_) {
427    __extbuf_     = __extbuf_min_;
428    __extbufnext_ = __extbuf_ + (__rhs.__extbufnext_ - __rhs.__extbuf_);
429    __extbufend_  = __extbuf_ + (__rhs.__extbufend_ - __rhs.__extbuf_);
430  } else {
431    __extbuf_     = __rhs.__extbuf_;
432    __extbufnext_ = __rhs.__extbufnext_;
433    __extbufend_  = __rhs.__extbufend_;
434  }
435  __ebs_           = __rhs.__ebs_;
436  __intbuf_        = __rhs.__intbuf_;
437  __ibs_           = __rhs.__ibs_;
438  __file_          = __rhs.__file_;
439  __cv_            = __rhs.__cv_;
440  __st_            = __rhs.__st_;
441  __st_last_       = __rhs.__st_last_;
442  __om_            = __rhs.__om_;
443  __cm_            = __rhs.__cm_;
444  __owns_eb_       = __rhs.__owns_eb_;
445  __owns_ib_       = __rhs.__owns_ib_;
446  __always_noconv_ = __rhs.__always_noconv_;
447  if (__rhs.pbase()) {
448    if (__rhs.pbase() == __rhs.__intbuf_)
449      this->setp(__intbuf_, __intbuf_ + (__rhs.epptr() - __rhs.pbase()));
450    else
451      this->setp((char_type*)__extbuf_, (char_type*)__extbuf_ + (__rhs.epptr() - __rhs.pbase()));
452    this->__pbump(__rhs.pptr() - __rhs.pbase());
453  } else if (__rhs.eback()) {
454    if (__rhs.eback() == __rhs.__intbuf_)
455      this->setg(__intbuf_, __intbuf_ + (__rhs.gptr() - __rhs.eback()), __intbuf_ + (__rhs.egptr() - __rhs.eback()));
456    else
457      this->setg((char_type*)__extbuf_,
458                 (char_type*)__extbuf_ + (__rhs.gptr() - __rhs.eback()),
459                 (char_type*)__extbuf_ + (__rhs.egptr() - __rhs.eback()));
460  }
461  __rhs.__extbuf_     = nullptr;
462  __rhs.__extbufnext_ = nullptr;
463  __rhs.__extbufend_  = nullptr;
464  __rhs.__ebs_        = 0;
465  __rhs.__intbuf_     = 0;
466  __rhs.__ibs_        = 0;
467  __rhs.__file_       = nullptr;
468  __rhs.__st_         = state_type();
469  __rhs.__st_last_    = state_type();
470  __rhs.__om_         = 0;
471  __rhs.__cm_         = 0;
472  __rhs.__owns_eb_    = false;
473  __rhs.__owns_ib_    = false;
474  __rhs.setg(0, 0, 0);
475  __rhs.setp(0, 0);
476}
477
478template <class _CharT, class _Traits>
479inline basic_filebuf<_CharT, _Traits>& basic_filebuf<_CharT, _Traits>::operator=(basic_filebuf&& __rhs) {
480  close();
481  swap(__rhs);
482  return *this;
483}
484
485template <class _CharT, class _Traits>
486basic_filebuf<_CharT, _Traits>::~basic_filebuf() {
487#  ifndef _LIBCPP_HAS_NO_EXCEPTIONS
488  try {
489#  endif // _LIBCPP_HAS_NO_EXCEPTIONS
490    close();
491#  ifndef _LIBCPP_HAS_NO_EXCEPTIONS
492  } catch (...) {
493  }
494#  endif // _LIBCPP_HAS_NO_EXCEPTIONS
495  if (__owns_eb_)
496    delete[] __extbuf_;
497  if (__owns_ib_)
498    delete[] __intbuf_;
499}
500
501template <class _CharT, class _Traits>
502void basic_filebuf<_CharT, _Traits>::swap(basic_filebuf& __rhs) {
503  basic_streambuf<char_type, traits_type>::swap(__rhs);
504  if (__extbuf_ != __extbuf_min_ && __rhs.__extbuf_ != __rhs.__extbuf_min_) {
505    // Neither *this nor __rhs uses the small buffer, so we can simply swap the pointers.
506    std::swap(__extbuf_, __rhs.__extbuf_);
507    std::swap(__extbufnext_, __rhs.__extbufnext_);
508    std::swap(__extbufend_, __rhs.__extbufend_);
509  } else {
510    ptrdiff_t __ln = __extbufnext_ ? __extbufnext_ - __extbuf_ : 0;
511    ptrdiff_t __le = __extbufend_ ? __extbufend_ - __extbuf_ : 0;
512    ptrdiff_t __rn = __rhs.__extbufnext_ ? __rhs.__extbufnext_ - __rhs.__extbuf_ : 0;
513    ptrdiff_t __re = __rhs.__extbufend_ ? __rhs.__extbufend_ - __rhs.__extbuf_ : 0;
514    if (__extbuf_ == __extbuf_min_ && __rhs.__extbuf_ != __rhs.__extbuf_min_) {
515      // *this uses the small buffer, but __rhs doesn't.
516      __extbuf_       = __rhs.__extbuf_;
517      __rhs.__extbuf_ = __rhs.__extbuf_min_;
518      std::memmove(__rhs.__extbuf_min_, __extbuf_min_, sizeof(__extbuf_min_));
519    } else if (__extbuf_ != __extbuf_min_ && __rhs.__extbuf_ == __rhs.__extbuf_min_) {
520      // *this doesn't use the small buffer, but __rhs does.
521      __rhs.__extbuf_ = __extbuf_;
522      __extbuf_       = __extbuf_min_;
523      std::memmove(__extbuf_min_, __rhs.__extbuf_min_, sizeof(__extbuf_min_));
524    } else {
525      // Both *this and __rhs use the small buffer.
526      char __tmp[sizeof(__extbuf_min_)];
527      std::memmove(__tmp, __extbuf_min_, sizeof(__extbuf_min_));
528      std::memmove(__extbuf_min_, __rhs.__extbuf_min_, sizeof(__extbuf_min_));
529      std::memmove(__rhs.__extbuf_min_, __tmp, sizeof(__extbuf_min_));
530    }
531    __extbufnext_       = __extbuf_ + __rn;
532    __extbufend_        = __extbuf_ + __re;
533    __rhs.__extbufnext_ = __rhs.__extbuf_ + __ln;
534    __rhs.__extbufend_  = __rhs.__extbuf_ + __le;
535  }
536  std::swap(__ebs_, __rhs.__ebs_);
537  std::swap(__intbuf_, __rhs.__intbuf_);
538  std::swap(__ibs_, __rhs.__ibs_);
539  std::swap(__file_, __rhs.__file_);
540  std::swap(__cv_, __rhs.__cv_);
541  std::swap(__st_, __rhs.__st_);
542  std::swap(__st_last_, __rhs.__st_last_);
543  std::swap(__om_, __rhs.__om_);
544  std::swap(__cm_, __rhs.__cm_);
545  std::swap(__owns_eb_, __rhs.__owns_eb_);
546  std::swap(__owns_ib_, __rhs.__owns_ib_);
547  std::swap(__always_noconv_, __rhs.__always_noconv_);
548  if (this->eback() == (char_type*)__rhs.__extbuf_min_) {
549    ptrdiff_t __n = this->gptr() - this->eback();
550    ptrdiff_t __e = this->egptr() - this->eback();
551    this->setg((char_type*)__extbuf_min_, (char_type*)__extbuf_min_ + __n, (char_type*)__extbuf_min_ + __e);
552  } else if (this->pbase() == (char_type*)__rhs.__extbuf_min_) {
553    ptrdiff_t __n = this->pptr() - this->pbase();
554    ptrdiff_t __e = this->epptr() - this->pbase();
555    this->setp((char_type*)__extbuf_min_, (char_type*)__extbuf_min_ + __e);
556    this->__pbump(__n);
557  }
558  if (__rhs.eback() == (char_type*)__extbuf_min_) {
559    ptrdiff_t __n = __rhs.gptr() - __rhs.eback();
560    ptrdiff_t __e = __rhs.egptr() - __rhs.eback();
561    __rhs.setg(
562        (char_type*)__rhs.__extbuf_min_, (char_type*)__rhs.__extbuf_min_ + __n, (char_type*)__rhs.__extbuf_min_ + __e);
563  } else if (__rhs.pbase() == (char_type*)__extbuf_min_) {
564    ptrdiff_t __n = __rhs.pptr() - __rhs.pbase();
565    ptrdiff_t __e = __rhs.epptr() - __rhs.pbase();
566    __rhs.setp((char_type*)__rhs.__extbuf_min_, (char_type*)__rhs.__extbuf_min_ + __e);
567    __rhs.__pbump(__n);
568  }
569}
570
571template <class _CharT, class _Traits>
572inline _LIBCPP_HIDE_FROM_ABI void swap(basic_filebuf<_CharT, _Traits>& __x, basic_filebuf<_CharT, _Traits>& __y) {
573  __x.swap(__y);
574}
575
576template <class _CharT, class _Traits>
577inline bool basic_filebuf<_CharT, _Traits>::is_open() const {
578  return __file_ != nullptr;
579}
580
581template <class _CharT, class _Traits>
582const char* basic_filebuf<_CharT, _Traits>::__make_mdstring(ios_base::openmode __mode) _NOEXCEPT {
583  switch (__mode & ~ios_base::ate) {
584  case ios_base::out:
585  case ios_base::out | ios_base::trunc:
586    return "w" _LIBCPP_FOPEN_CLOEXEC_MODE;
587  case ios_base::out | ios_base::app:
588  case ios_base::app:
589    return "a" _LIBCPP_FOPEN_CLOEXEC_MODE;
590  case ios_base::in:
591    return "r" _LIBCPP_FOPEN_CLOEXEC_MODE;
592  case ios_base::in | ios_base::out:
593    return "r+" _LIBCPP_FOPEN_CLOEXEC_MODE;
594  case ios_base::in | ios_base::out | ios_base::trunc:
595    return "w+" _LIBCPP_FOPEN_CLOEXEC_MODE;
596  case ios_base::in | ios_base::out | ios_base::app:
597  case ios_base::in | ios_base::app:
598    return "a+" _LIBCPP_FOPEN_CLOEXEC_MODE;
599  case ios_base::out | ios_base::binary:
600  case ios_base::out | ios_base::trunc | ios_base::binary:
601    return "wb" _LIBCPP_FOPEN_CLOEXEC_MODE;
602  case ios_base::out | ios_base::app | ios_base::binary:
603  case ios_base::app | ios_base::binary:
604    return "ab" _LIBCPP_FOPEN_CLOEXEC_MODE;
605  case ios_base::in | ios_base::binary:
606    return "rb" _LIBCPP_FOPEN_CLOEXEC_MODE;
607  case ios_base::in | ios_base::out | ios_base::binary:
608    return "r+b" _LIBCPP_FOPEN_CLOEXEC_MODE;
609  case ios_base::in | ios_base::out | ios_base::trunc | ios_base::binary:
610    return "w+b" _LIBCPP_FOPEN_CLOEXEC_MODE;
611  case ios_base::in | ios_base::out | ios_base::app | ios_base::binary:
612  case ios_base::in | ios_base::app | ios_base::binary:
613    return "a+b" _LIBCPP_FOPEN_CLOEXEC_MODE;
614#  if _LIBCPP_STD_VER >= 23
615  case ios_base::out | ios_base::noreplace:
616  case ios_base::out | ios_base::trunc | ios_base::noreplace:
617    return "wx" _LIBCPP_FOPEN_CLOEXEC_MODE;
618  case ios_base::in | ios_base::out | ios_base::trunc | ios_base::noreplace:
619    return "w+x" _LIBCPP_FOPEN_CLOEXEC_MODE;
620  case ios_base::out | ios_base::binary | ios_base::noreplace:
621  case ios_base::out | ios_base::trunc | ios_base::binary | ios_base::noreplace:
622    return "wbx" _LIBCPP_FOPEN_CLOEXEC_MODE;
623  case ios_base::in | ios_base::out | ios_base::trunc | ios_base::binary | ios_base::noreplace:
624    return "w+bx" _LIBCPP_FOPEN_CLOEXEC_MODE;
625#  endif // _LIBCPP_STD_VER >= 23
626  default:
627    return nullptr;
628  }
629  __libcpp_unreachable();
630}
631
632#  ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
633template <class _CharT, class _Traits>
634const wchar_t* basic_filebuf<_CharT, _Traits>::__make_mdwstring(ios_base::openmode __mode) _NOEXCEPT {
635  switch (__mode & ~ios_base::ate) {
636  case ios_base::out:
637  case ios_base::out | ios_base::trunc:
638    return L"w";
639  case ios_base::out | ios_base::app:
640  case ios_base::app:
641    return L"a";
642  case ios_base::in:
643    return L"r";
644  case ios_base::in | ios_base::out:
645    return L"r+";
646  case ios_base::in | ios_base::out | ios_base::trunc:
647    return L"w+";
648  case ios_base::in | ios_base::out | ios_base::app:
649  case ios_base::in | ios_base::app:
650    return L"a+";
651  case ios_base::out | ios_base::binary:
652  case ios_base::out | ios_base::trunc | ios_base::binary:
653    return L"wb";
654  case ios_base::out | ios_base::app | ios_base::binary:
655  case ios_base::app | ios_base::binary:
656    return L"ab";
657  case ios_base::in | ios_base::binary:
658    return L"rb";
659  case ios_base::in | ios_base::out | ios_base::binary:
660    return L"r+b";
661  case ios_base::in | ios_base::out | ios_base::trunc | ios_base::binary:
662    return L"w+b";
663  case ios_base::in | ios_base::out | ios_base::app | ios_base::binary:
664  case ios_base::in | ios_base::app | ios_base::binary:
665    return L"a+b";
666#    if _LIBCPP_STD_VER >= 23
667  case ios_base::out | ios_base::noreplace:
668  case ios_base::out | ios_base::trunc | ios_base::noreplace:
669    return L"wx";
670  case ios_base::in | ios_base::out | ios_base::trunc | ios_base::noreplace:
671    return L"w+x";
672  case ios_base::out | ios_base::binary | ios_base::noreplace:
673  case ios_base::out | ios_base::trunc | ios_base::binary | ios_base::noreplace:
674    return L"wbx";
675  case ios_base::in | ios_base::out | ios_base::trunc | ios_base::binary | ios_base::noreplace:
676    return L"w+bx";
677#    endif // _LIBCPP_STD_VER >= 23
678  default:
679    return nullptr;
680  }
681  __libcpp_unreachable();
682}
683#  endif
684
685template <class _CharT, class _Traits>
686basic_filebuf<_CharT, _Traits>* basic_filebuf<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode) {
687  if (__file_)
688    return nullptr;
689  const char* __mdstr = __make_mdstring(__mode);
690  if (!__mdstr)
691    return nullptr;
692
693  return __do_open(fopen(__s, __mdstr), __mode);
694}
695
696template <class _CharT, class _Traits>
697inline basic_filebuf<_CharT, _Traits>* basic_filebuf<_CharT, _Traits>::__open(int __fd, ios_base::openmode __mode) {
698  if (__file_)
699    return nullptr;
700  const char* __mdstr = __make_mdstring(__mode);
701  if (!__mdstr)
702    return nullptr;
703
704  return __do_open(fdopen(__fd, __mdstr), __mode);
705}
706
707#  ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
708// This is basically the same as the char* overload except that it uses _wfopen
709// and long mode strings.
710template <class _CharT, class _Traits>
711basic_filebuf<_CharT, _Traits>* basic_filebuf<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode) {
712  if (__file_)
713    return nullptr;
714  const wchar_t* __mdstr = __make_mdwstring(__mode);
715  if (!__mdstr)
716    return nullptr;
717
718  return __do_open(_wfopen(__s, __mdstr), __mode);
719}
720#  endif
721
722template <class _CharT, class _Traits>
723inline basic_filebuf<_CharT, _Traits>*
724basic_filebuf<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode) {
725  return open(__s.c_str(), __mode);
726}
727
728template <class _CharT, class _Traits>
729basic_filebuf<_CharT, _Traits>* basic_filebuf<_CharT, _Traits>::close() {
730  basic_filebuf<_CharT, _Traits>* __rt = nullptr;
731  if (__file_) {
732    __rt = this;
733    unique_ptr<FILE, int (*)(FILE*)> __h(__file_, fclose);
734    if (sync())
735      __rt = nullptr;
736    if (fclose(__h.release()))
737      __rt = nullptr;
738    __file_ = nullptr;
739    setbuf(0, 0);
740  }
741  return __rt;
742}
743
744template <class _CharT, class _Traits>
745typename basic_filebuf<_CharT, _Traits>::int_type basic_filebuf<_CharT, _Traits>::underflow() {
746  if (__file_ == nullptr)
747    return traits_type::eof();
748  bool __initial = __read_mode();
749  char_type __1buf;
750  if (this->gptr() == nullptr)
751    this->setg(&__1buf, &__1buf + 1, &__1buf + 1);
752  const size_t __unget_sz = __initial ? 0 : std::min<size_t>((this->egptr() - this->eback()) / 2, 4);
753  int_type __c            = traits_type::eof();
754  if (this->gptr() == this->egptr()) {
755    std::memmove(this->eback(), this->egptr() - __unget_sz, __unget_sz * sizeof(char_type));
756    if (__always_noconv_) {
757      size_t __nmemb = static_cast<size_t>(this->egptr() - this->eback() - __unget_sz);
758      __nmemb        = ::fread(this->eback() + __unget_sz, 1, __nmemb, __file_);
759      if (__nmemb != 0) {
760        this->setg(this->eback(), this->eback() + __unget_sz, this->eback() + __unget_sz + __nmemb);
761        __c = traits_type::to_int_type(*this->gptr());
762      }
763    } else {
764      if (__extbufend_ != __extbufnext_) {
765        _LIBCPP_ASSERT_NON_NULL(__extbufnext_ != nullptr, "underflow moving from nullptr");
766        _LIBCPP_ASSERT_NON_NULL(__extbuf_ != nullptr, "underflow moving into nullptr");
767        std::memmove(__extbuf_, __extbufnext_, __extbufend_ - __extbufnext_);
768      }
769      __extbufnext_ = __extbuf_ + (__extbufend_ - __extbufnext_);
770      __extbufend_  = __extbuf_ + (__extbuf_ == __extbuf_min_ ? sizeof(__extbuf_min_) : __ebs_);
771      size_t __nmemb =
772          std::min(static_cast<size_t>(__ibs_ - __unget_sz), static_cast<size_t>(__extbufend_ - __extbufnext_));
773      codecvt_base::result __r;
774      __st_last_  = __st_;
775      size_t __nr = fread((void*)const_cast<char*>(__extbufnext_), 1, __nmemb, __file_);
776      if (__nr != 0) {
777        if (!__cv_)
778          __throw_bad_cast();
779
780        __extbufend_ = __extbufnext_ + __nr;
781        char_type* __inext;
782        __r = __cv_->in(
783            __st_, __extbuf_, __extbufend_, __extbufnext_, this->eback() + __unget_sz, this->eback() + __ibs_, __inext);
784        if (__r == codecvt_base::noconv) {
785          this->setg((char_type*)__extbuf_, (char_type*)__extbuf_, (char_type*)const_cast<char*>(__extbufend_));
786          __c = traits_type::to_int_type(*this->gptr());
787        } else if (__inext != this->eback() + __unget_sz) {
788          this->setg(this->eback(), this->eback() + __unget_sz, __inext);
789          __c = traits_type::to_int_type(*this->gptr());
790        }
791      }
792    }
793  } else
794    __c = traits_type::to_int_type(*this->gptr());
795  if (this->eback() == &__1buf)
796    this->setg(nullptr, nullptr, nullptr);
797  return __c;
798}
799
800template <class _CharT, class _Traits>
801typename basic_filebuf<_CharT, _Traits>::int_type basic_filebuf<_CharT, _Traits>::pbackfail(int_type __c) {
802  if (__file_ && this->eback() < this->gptr()) {
803    if (traits_type::eq_int_type(__c, traits_type::eof())) {
804      this->gbump(-1);
805      return traits_type::not_eof(__c);
806    }
807    if ((__om_ & ios_base::out) || traits_type::eq(traits_type::to_char_type(__c), this->gptr()[-1])) {
808      this->gbump(-1);
809      *this->gptr() = traits_type::to_char_type(__c);
810      return __c;
811    }
812  }
813  return traits_type::eof();
814}
815
816template <class _CharT, class _Traits>
817typename basic_filebuf<_CharT, _Traits>::int_type basic_filebuf<_CharT, _Traits>::overflow(int_type __c) {
818  if (__file_ == nullptr)
819    return traits_type::eof();
820  __write_mode();
821  char_type __1buf;
822  char_type* __pb_save  = this->pbase();
823  char_type* __epb_save = this->epptr();
824  if (!traits_type::eq_int_type(__c, traits_type::eof())) {
825    if (this->pptr() == nullptr)
826      this->setp(&__1buf, &__1buf + 1);
827    *this->pptr() = traits_type::to_char_type(__c);
828    this->pbump(1);
829  }
830  if (this->pptr() != this->pbase()) {
831    if (__always_noconv_) {
832      size_t __nmemb = static_cast<size_t>(this->pptr() - this->pbase());
833      if (std::fwrite(this->pbase(), sizeof(char_type), __nmemb, __file_) != __nmemb)
834        return traits_type::eof();
835    } else {
836      char* __extbe = __extbuf_;
837      codecvt_base::result __r;
838      do {
839        if (!__cv_)
840          __throw_bad_cast();
841
842        const char_type* __e;
843        __r = __cv_->out(__st_, this->pbase(), this->pptr(), __e, __extbuf_, __extbuf_ + __ebs_, __extbe);
844        if (__e == this->pbase())
845          return traits_type::eof();
846        if (__r == codecvt_base::noconv) {
847          size_t __nmemb = static_cast<size_t>(this->pptr() - this->pbase());
848          if (std::fwrite(this->pbase(), 1, __nmemb, __file_) != __nmemb)
849            return traits_type::eof();
850        } else if (__r == codecvt_base::ok || __r == codecvt_base::partial) {
851          size_t __nmemb = static_cast<size_t>(__extbe - __extbuf_);
852          if (fwrite(__extbuf_, 1, __nmemb, __file_) != __nmemb)
853            return traits_type::eof();
854          if (__r == codecvt_base::partial) {
855            this->setp(const_cast<char_type*>(__e), this->pptr());
856            this->__pbump(this->epptr() - this->pbase());
857          }
858        } else
859          return traits_type::eof();
860      } while (__r == codecvt_base::partial);
861    }
862    this->setp(__pb_save, __epb_save);
863  }
864  return traits_type::not_eof(__c);
865}
866
867template <class _CharT, class _Traits>
868basic_streambuf<_CharT, _Traits>* basic_filebuf<_CharT, _Traits>::setbuf(char_type* __s, streamsize __n) {
869  this->setg(nullptr, nullptr, nullptr);
870  this->setp(nullptr, nullptr);
871  __request_unbuffered_mode(__s, __n);
872  if (__owns_eb_)
873    delete[] __extbuf_;
874  if (__owns_ib_)
875    delete[] __intbuf_;
876  __ebs_ = __n;
877  if (__ebs_ > sizeof(__extbuf_min_)) {
878    if (__always_noconv_ && __s) {
879      __extbuf_  = (char*)__s;
880      __owns_eb_ = false;
881    } else {
882      __extbuf_  = new char[__ebs_];
883      __owns_eb_ = true;
884    }
885  } else {
886    __extbuf_  = __extbuf_min_;
887    __ebs_     = sizeof(__extbuf_min_);
888    __owns_eb_ = false;
889  }
890  if (!__always_noconv_) {
891    __ibs_ = max<streamsize>(__n, sizeof(__extbuf_min_));
892    if (__s && __ibs_ > sizeof(__extbuf_min_)) {
893      __intbuf_  = __s;
894      __owns_ib_ = false;
895    } else {
896      __intbuf_  = new char_type[__ibs_];
897      __owns_ib_ = true;
898    }
899  } else {
900    __ibs_     = 0;
901    __intbuf_  = nullptr;
902    __owns_ib_ = false;
903  }
904  return this;
905}
906
907template <class _CharT, class _Traits>
908typename basic_filebuf<_CharT, _Traits>::pos_type
909basic_filebuf<_CharT, _Traits>::seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode) {
910  if (!__cv_)
911    __throw_bad_cast();
912
913  int __width = __cv_->encoding();
914  if (__file_ == nullptr || (__width <= 0 && __off != 0) || sync())
915    return pos_type(off_type(-1));
916  // __width > 0 || __off == 0
917  int __whence;
918  switch (__way) {
919  case ios_base::beg:
920    __whence = SEEK_SET;
921    break;
922  case ios_base::cur:
923    __whence = SEEK_CUR;
924    break;
925  case ios_base::end:
926    __whence = SEEK_END;
927    break;
928  default:
929    return pos_type(off_type(-1));
930  }
931#  if defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
932  if (fseek(__file_, __width > 0 ? __width * __off : 0, __whence))
933    return pos_type(off_type(-1));
934  pos_type __r = ftell(__file_);
935#  else
936  if (::fseeko(__file_, __width > 0 ? __width * __off : 0, __whence))
937    return pos_type(off_type(-1));
938  pos_type __r = ftello(__file_);
939#  endif
940  __r.state(__st_);
941  return __r;
942}
943
944template <class _CharT, class _Traits>
945typename basic_filebuf<_CharT, _Traits>::pos_type
946basic_filebuf<_CharT, _Traits>::seekpos(pos_type __sp, ios_base::openmode) {
947  if (__file_ == nullptr || sync())
948    return pos_type(off_type(-1));
949#  if defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
950  if (fseek(__file_, __sp, SEEK_SET))
951    return pos_type(off_type(-1));
952#  else
953  if (::fseeko(__file_, __sp, SEEK_SET))
954    return pos_type(off_type(-1));
955#  endif
956  __st_ = __sp.state();
957  return __sp;
958}
959
960template <class _CharT, class _Traits>
961int basic_filebuf<_CharT, _Traits>::sync() {
962  if (__file_ == nullptr)
963    return 0;
964  if (!__cv_)
965    __throw_bad_cast();
966
967  if (__cm_ & ios_base::out) {
968    if (this->pptr() != this->pbase())
969      if (overflow() == traits_type::eof())
970        return -1;
971    codecvt_base::result __r;
972    do {
973      char* __extbe;
974      __r            = __cv_->unshift(__st_, __extbuf_, __extbuf_ + __ebs_, __extbe);
975      size_t __nmemb = static_cast<size_t>(__extbe - __extbuf_);
976      if (fwrite(__extbuf_, 1, __nmemb, __file_) != __nmemb)
977        return -1;
978    } while (__r == codecvt_base::partial);
979    if (__r == codecvt_base::error)
980      return -1;
981    if (fflush(__file_))
982      return -1;
983  } else if (__cm_ & ios_base::in) {
984    off_type __c;
985    state_type __state = __st_last_;
986    bool __update_st   = false;
987    if (__always_noconv_)
988      __c = this->egptr() - this->gptr();
989    else {
990      int __width = __cv_->encoding();
991      __c         = __extbufend_ - __extbufnext_;
992      if (__width > 0)
993        __c += __width * (this->egptr() - this->gptr());
994      else {
995        if (this->gptr() != this->egptr()) {
996          const int __off = __cv_->length(__state, __extbuf_, __extbufnext_, this->gptr() - this->eback());
997          __c += __extbufnext_ - __extbuf_ - __off;
998          __update_st = true;
999        }
1000      }
1001    }
1002#  if defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
1003    if (fseek(__file_, -__c, SEEK_CUR))
1004      return -1;
1005#  else
1006    if (::fseeko(__file_, -__c, SEEK_CUR))
1007      return -1;
1008#  endif
1009    if (__update_st)
1010      __st_ = __state;
1011    __extbufnext_ = __extbufend_ = __extbuf_;
1012    this->setg(nullptr, nullptr, nullptr);
1013    __cm_ = 0;
1014  }
1015  return 0;
1016}
1017
1018template <class _CharT, class _Traits>
1019void basic_filebuf<_CharT, _Traits>::imbue(const locale& __loc) {
1020  sync();
1021  __cv_            = &std::use_facet<codecvt<char_type, char, state_type> >(__loc);
1022  bool __old_anc   = __always_noconv_;
1023  __always_noconv_ = __cv_->always_noconv();
1024  if (__old_anc != __always_noconv_) {
1025    this->setg(nullptr, nullptr, nullptr);
1026    this->setp(nullptr, nullptr);
1027    // invariant, char_type is char, else we couldn't get here
1028    if (__always_noconv_) // need to dump __intbuf_
1029    {
1030      if (__owns_eb_)
1031        delete[] __extbuf_;
1032      __owns_eb_ = __owns_ib_;
1033      __ebs_     = __ibs_;
1034      __extbuf_  = (char*)__intbuf_;
1035      __ibs_     = 0;
1036      __intbuf_  = nullptr;
1037      __owns_ib_ = false;
1038    } else // need to obtain an __intbuf_.
1039    {      // If __extbuf_ is user-supplied, use it, else new __intbuf_
1040      if (!__owns_eb_ && __extbuf_ != __extbuf_min_) {
1041        __ibs_     = __ebs_;
1042        __intbuf_  = (char_type*)__extbuf_;
1043        __owns_ib_ = false;
1044        __extbuf_  = new char[__ebs_];
1045        __owns_eb_ = true;
1046      } else {
1047        __ibs_     = __ebs_;
1048        __intbuf_  = new char_type[__ibs_];
1049        __owns_ib_ = true;
1050      }
1051    }
1052  }
1053}
1054
1055template <class _CharT, class _Traits>
1056bool basic_filebuf<_CharT, _Traits>::__read_mode() {
1057  if (!(__cm_ & ios_base::in)) {
1058    this->setp(nullptr, nullptr);
1059    if (__always_noconv_)
1060      this->setg((char_type*)__extbuf_, (char_type*)__extbuf_ + __ebs_, (char_type*)__extbuf_ + __ebs_);
1061    else
1062      this->setg(__intbuf_, __intbuf_ + __ibs_, __intbuf_ + __ibs_);
1063    __cm_ = ios_base::in;
1064    return true;
1065  }
1066  return false;
1067}
1068
1069template <class _CharT, class _Traits>
1070void basic_filebuf<_CharT, _Traits>::__write_mode() {
1071  if (!(__cm_ & ios_base::out)) {
1072    this->setg(nullptr, nullptr, nullptr);
1073    if (__ebs_ > sizeof(__extbuf_min_)) {
1074      if (__always_noconv_)
1075        this->setp((char_type*)__extbuf_, (char_type*)__extbuf_ + (__ebs_ - 1));
1076      else
1077        this->setp(__intbuf_, __intbuf_ + (__ibs_ - 1));
1078    } else
1079      this->setp(nullptr, nullptr);
1080    __cm_ = ios_base::out;
1081  }
1082}
1083
1084// basic_ifstream
1085
1086template <class _CharT, class _Traits>
1087class _LIBCPP_TEMPLATE_VIS basic_ifstream : public basic_istream<_CharT, _Traits> {
1088public:
1089  typedef _CharT char_type;
1090  typedef _Traits traits_type;
1091  typedef typename traits_type::int_type int_type;
1092  typedef typename traits_type::pos_type pos_type;
1093  typedef typename traits_type::off_type off_type;
1094#  if _LIBCPP_STD_VER >= 26
1095  using native_handle_type = typename basic_filebuf<_CharT, _Traits>::native_handle_type;
1096#  endif
1097
1098  _LIBCPP_HIDE_FROM_ABI basic_ifstream();
1099  _LIBCPP_HIDE_FROM_ABI explicit basic_ifstream(const char* __s, ios_base::openmode __mode = ios_base::in);
1100#  ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1101  _LIBCPP_HIDE_FROM_ABI explicit basic_ifstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::in);
1102#  endif
1103  _LIBCPP_HIDE_FROM_ABI explicit basic_ifstream(const string& __s, ios_base::openmode __mode = ios_base::in);
1104#  if _LIBCPP_STD_VER >= 17
1105  template <class _Tp, class = enable_if_t<is_same_v<_Tp, filesystem::path>>>
1106  _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY
1107      _LIBCPP_HIDE_FROM_ABI explicit basic_ifstream(const _Tp& __p, ios_base::openmode __mode = ios_base::in)
1108      : basic_ifstream(__p.c_str(), __mode) {}
1109#  endif // _LIBCPP_STD_VER >= 17
1110  _LIBCPP_HIDE_FROM_ABI basic_ifstream(basic_ifstream&& __rhs);
1111  _LIBCPP_HIDE_FROM_ABI basic_ifstream& operator=(basic_ifstream&& __rhs);
1112  _LIBCPP_HIDE_FROM_ABI void swap(basic_ifstream& __rhs);
1113
1114  _LIBCPP_HIDE_FROM_ABI basic_filebuf<char_type, traits_type>* rdbuf() const;
1115#  if _LIBCPP_STD_VER >= 26
1116  _LIBCPP_HIDE_FROM_ABI native_handle_type native_handle() const noexcept { return rdbuf()->native_handle(); }
1117#  endif
1118  _LIBCPP_HIDE_FROM_ABI bool is_open() const;
1119  void open(const char* __s, ios_base::openmode __mode = ios_base::in);
1120#  ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1121  void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::in);
1122#  endif
1123  void open(const string& __s, ios_base::openmode __mode = ios_base::in);
1124#  if _LIBCPP_STD_VER >= 17
1125  _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY _LIBCPP_HIDE_FROM_ABI void
1126  open(const filesystem::path& __p, ios_base::openmode __mode = ios_base::in) {
1127    return open(__p.c_str(), __mode);
1128  }
1129#  endif // _LIBCPP_STD_VER >= 17
1130
1131  _LIBCPP_HIDE_FROM_ABI void __open(int __fd, ios_base::openmode __mode);
1132  _LIBCPP_HIDE_FROM_ABI void close();
1133
1134private:
1135  basic_filebuf<char_type, traits_type> __sb_;
1136};
1137
1138template <class _CharT, class _Traits>
1139inline basic_ifstream<_CharT, _Traits>::basic_ifstream() : basic_istream<char_type, traits_type>(&__sb_) {}
1140
1141template <class _CharT, class _Traits>
1142inline basic_ifstream<_CharT, _Traits>::basic_ifstream(const char* __s, ios_base::openmode __mode)
1143    : basic_istream<char_type, traits_type>(&__sb_) {
1144  if (__sb_.open(__s, __mode | ios_base::in) == nullptr)
1145    this->setstate(ios_base::failbit);
1146}
1147
1148#  ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1149template <class _CharT, class _Traits>
1150inline basic_ifstream<_CharT, _Traits>::basic_ifstream(const wchar_t* __s, ios_base::openmode __mode)
1151    : basic_istream<char_type, traits_type>(&__sb_) {
1152  if (__sb_.open(__s, __mode | ios_base::in) == nullptr)
1153    this->setstate(ios_base::failbit);
1154}
1155#  endif
1156
1157template <class _CharT, class _Traits>
1158inline basic_ifstream<_CharT, _Traits>::basic_ifstream(const string& __s, ios_base::openmode __mode)
1159    : basic_istream<char_type, traits_type>(&__sb_) {
1160  if (__sb_.open(__s, __mode | ios_base::in) == nullptr)
1161    this->setstate(ios_base::failbit);
1162}
1163
1164template <class _CharT, class _Traits>
1165inline basic_ifstream<_CharT, _Traits>::basic_ifstream(basic_ifstream&& __rhs)
1166    : basic_istream<char_type, traits_type>(std::move(__rhs)), __sb_(std::move(__rhs.__sb_)) {
1167  this->set_rdbuf(&__sb_);
1168}
1169
1170template <class _CharT, class _Traits>
1171inline basic_ifstream<_CharT, _Traits>& basic_ifstream<_CharT, _Traits>::operator=(basic_ifstream&& __rhs) {
1172  basic_istream<char_type, traits_type>::operator=(std::move(__rhs));
1173  __sb_ = std::move(__rhs.__sb_);
1174  return *this;
1175}
1176
1177template <class _CharT, class _Traits>
1178inline void basic_ifstream<_CharT, _Traits>::swap(basic_ifstream& __rhs) {
1179  basic_istream<char_type, traits_type>::swap(__rhs);
1180  __sb_.swap(__rhs.__sb_);
1181}
1182
1183template <class _CharT, class _Traits>
1184inline _LIBCPP_HIDE_FROM_ABI void swap(basic_ifstream<_CharT, _Traits>& __x, basic_ifstream<_CharT, _Traits>& __y) {
1185  __x.swap(__y);
1186}
1187
1188template <class _CharT, class _Traits>
1189inline basic_filebuf<_CharT, _Traits>* basic_ifstream<_CharT, _Traits>::rdbuf() const {
1190  return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
1191}
1192
1193template <class _CharT, class _Traits>
1194inline bool basic_ifstream<_CharT, _Traits>::is_open() const {
1195  return __sb_.is_open();
1196}
1197
1198template <class _CharT, class _Traits>
1199void basic_ifstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode) {
1200  if (__sb_.open(__s, __mode | ios_base::in))
1201    this->clear();
1202  else
1203    this->setstate(ios_base::failbit);
1204}
1205
1206#  ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1207template <class _CharT, class _Traits>
1208void basic_ifstream<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode) {
1209  if (__sb_.open(__s, __mode | ios_base::in))
1210    this->clear();
1211  else
1212    this->setstate(ios_base::failbit);
1213}
1214#  endif
1215
1216template <class _CharT, class _Traits>
1217void basic_ifstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode) {
1218  if (__sb_.open(__s, __mode | ios_base::in))
1219    this->clear();
1220  else
1221    this->setstate(ios_base::failbit);
1222}
1223
1224template <class _CharT, class _Traits>
1225inline void basic_ifstream<_CharT, _Traits>::__open(int __fd, ios_base::openmode __mode) {
1226  if (__sb_.__open(__fd, __mode | ios_base::in))
1227    this->clear();
1228  else
1229    this->setstate(ios_base::failbit);
1230}
1231
1232template <class _CharT, class _Traits>
1233inline void basic_ifstream<_CharT, _Traits>::close() {
1234  if (__sb_.close() == 0)
1235    this->setstate(ios_base::failbit);
1236}
1237
1238// basic_ofstream
1239
1240template <class _CharT, class _Traits>
1241class _LIBCPP_TEMPLATE_VIS basic_ofstream : public basic_ostream<_CharT, _Traits> {
1242public:
1243  typedef _CharT char_type;
1244  typedef _Traits traits_type;
1245  typedef typename traits_type::int_type int_type;
1246  typedef typename traits_type::pos_type pos_type;
1247  typedef typename traits_type::off_type off_type;
1248#  if _LIBCPP_STD_VER >= 26
1249  using native_handle_type = typename basic_filebuf<_CharT, _Traits>::native_handle_type;
1250#  endif
1251
1252  _LIBCPP_HIDE_FROM_ABI basic_ofstream();
1253  _LIBCPP_HIDE_FROM_ABI explicit basic_ofstream(const char* __s, ios_base::openmode __mode = ios_base::out);
1254#  ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1255  _LIBCPP_HIDE_FROM_ABI explicit basic_ofstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::out);
1256#  endif
1257  _LIBCPP_HIDE_FROM_ABI explicit basic_ofstream(const string& __s, ios_base::openmode __mode = ios_base::out);
1258
1259#  if _LIBCPP_STD_VER >= 17
1260  template <class _Tp, class = enable_if_t<is_same_v<_Tp, filesystem::path>>>
1261  _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY
1262      _LIBCPP_HIDE_FROM_ABI explicit basic_ofstream(const _Tp& __p, ios_base::openmode __mode = ios_base::out)
1263      : basic_ofstream(__p.c_str(), __mode) {}
1264#  endif // _LIBCPP_STD_VER >= 17
1265
1266  _LIBCPP_HIDE_FROM_ABI basic_ofstream(basic_ofstream&& __rhs);
1267  _LIBCPP_HIDE_FROM_ABI basic_ofstream& operator=(basic_ofstream&& __rhs);
1268  _LIBCPP_HIDE_FROM_ABI void swap(basic_ofstream& __rhs);
1269
1270  _LIBCPP_HIDE_FROM_ABI basic_filebuf<char_type, traits_type>* rdbuf() const;
1271#  if _LIBCPP_STD_VER >= 26
1272  _LIBCPP_HIDE_FROM_ABI native_handle_type native_handle() const noexcept { return rdbuf()->native_handle(); }
1273#  endif
1274  _LIBCPP_HIDE_FROM_ABI bool is_open() const;
1275  void open(const char* __s, ios_base::openmode __mode = ios_base::out);
1276#  ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1277  void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::out);
1278#  endif
1279  void open(const string& __s, ios_base::openmode __mode = ios_base::out);
1280
1281#  if _LIBCPP_STD_VER >= 17
1282  _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY _LIBCPP_HIDE_FROM_ABI void
1283  open(const filesystem::path& __p, ios_base::openmode __mode = ios_base::out) {
1284    return open(__p.c_str(), __mode);
1285  }
1286#  endif // _LIBCPP_STD_VER >= 17
1287
1288  _LIBCPP_HIDE_FROM_ABI void __open(int __fd, ios_base::openmode __mode);
1289  _LIBCPP_HIDE_FROM_ABI void close();
1290
1291private:
1292  basic_filebuf<char_type, traits_type> __sb_;
1293};
1294
1295template <class _CharT, class _Traits>
1296inline basic_ofstream<_CharT, _Traits>::basic_ofstream() : basic_ostream<char_type, traits_type>(&__sb_) {}
1297
1298template <class _CharT, class _Traits>
1299inline basic_ofstream<_CharT, _Traits>::basic_ofstream(const char* __s, ios_base::openmode __mode)
1300    : basic_ostream<char_type, traits_type>(&__sb_) {
1301  if (__sb_.open(__s, __mode | ios_base::out) == nullptr)
1302    this->setstate(ios_base::failbit);
1303}
1304
1305#  ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1306template <class _CharT, class _Traits>
1307inline basic_ofstream<_CharT, _Traits>::basic_ofstream(const wchar_t* __s, ios_base::openmode __mode)
1308    : basic_ostream<char_type, traits_type>(&__sb_) {
1309  if (__sb_.open(__s, __mode | ios_base::out) == nullptr)
1310    this->setstate(ios_base::failbit);
1311}
1312#  endif
1313
1314template <class _CharT, class _Traits>
1315inline basic_ofstream<_CharT, _Traits>::basic_ofstream(const string& __s, ios_base::openmode __mode)
1316    : basic_ostream<char_type, traits_type>(&__sb_) {
1317  if (__sb_.open(__s, __mode | ios_base::out) == nullptr)
1318    this->setstate(ios_base::failbit);
1319}
1320
1321template <class _CharT, class _Traits>
1322inline basic_ofstream<_CharT, _Traits>::basic_ofstream(basic_ofstream&& __rhs)
1323    : basic_ostream<char_type, traits_type>(std::move(__rhs)), __sb_(std::move(__rhs.__sb_)) {
1324  this->set_rdbuf(&__sb_);
1325}
1326
1327template <class _CharT, class _Traits>
1328inline basic_ofstream<_CharT, _Traits>& basic_ofstream<_CharT, _Traits>::operator=(basic_ofstream&& __rhs) {
1329  basic_ostream<char_type, traits_type>::operator=(std::move(__rhs));
1330  __sb_ = std::move(__rhs.__sb_);
1331  return *this;
1332}
1333
1334template <class _CharT, class _Traits>
1335inline void basic_ofstream<_CharT, _Traits>::swap(basic_ofstream& __rhs) {
1336  basic_ostream<char_type, traits_type>::swap(__rhs);
1337  __sb_.swap(__rhs.__sb_);
1338}
1339
1340template <class _CharT, class _Traits>
1341inline _LIBCPP_HIDE_FROM_ABI void swap(basic_ofstream<_CharT, _Traits>& __x, basic_ofstream<_CharT, _Traits>& __y) {
1342  __x.swap(__y);
1343}
1344
1345template <class _CharT, class _Traits>
1346inline basic_filebuf<_CharT, _Traits>* basic_ofstream<_CharT, _Traits>::rdbuf() const {
1347  return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
1348}
1349
1350template <class _CharT, class _Traits>
1351inline bool basic_ofstream<_CharT, _Traits>::is_open() const {
1352  return __sb_.is_open();
1353}
1354
1355template <class _CharT, class _Traits>
1356void basic_ofstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode) {
1357  if (__sb_.open(__s, __mode | ios_base::out))
1358    this->clear();
1359  else
1360    this->setstate(ios_base::failbit);
1361}
1362
1363#  ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1364template <class _CharT, class _Traits>
1365void basic_ofstream<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode) {
1366  if (__sb_.open(__s, __mode | ios_base::out))
1367    this->clear();
1368  else
1369    this->setstate(ios_base::failbit);
1370}
1371#  endif
1372
1373template <class _CharT, class _Traits>
1374void basic_ofstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode) {
1375  if (__sb_.open(__s, __mode | ios_base::out))
1376    this->clear();
1377  else
1378    this->setstate(ios_base::failbit);
1379}
1380
1381template <class _CharT, class _Traits>
1382inline void basic_ofstream<_CharT, _Traits>::__open(int __fd, ios_base::openmode __mode) {
1383  if (__sb_.__open(__fd, __mode | ios_base::out))
1384    this->clear();
1385  else
1386    this->setstate(ios_base::failbit);
1387}
1388
1389template <class _CharT, class _Traits>
1390inline void basic_ofstream<_CharT, _Traits>::close() {
1391  if (__sb_.close() == nullptr)
1392    this->setstate(ios_base::failbit);
1393}
1394
1395// basic_fstream
1396
1397template <class _CharT, class _Traits>
1398class _LIBCPP_TEMPLATE_VIS basic_fstream : public basic_iostream<_CharT, _Traits> {
1399public:
1400  typedef _CharT char_type;
1401  typedef _Traits traits_type;
1402  typedef typename traits_type::int_type int_type;
1403  typedef typename traits_type::pos_type pos_type;
1404  typedef typename traits_type::off_type off_type;
1405#  if _LIBCPP_STD_VER >= 26
1406  using native_handle_type = typename basic_filebuf<_CharT, _Traits>::native_handle_type;
1407#  endif
1408
1409  _LIBCPP_HIDE_FROM_ABI basic_fstream();
1410  _LIBCPP_HIDE_FROM_ABI explicit basic_fstream(const char* __s,
1411                                               ios_base::openmode __mode = ios_base::in | ios_base::out);
1412#  ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1413  _LIBCPP_HIDE_FROM_ABI explicit basic_fstream(const wchar_t* __s,
1414                                               ios_base::openmode __mode = ios_base::in | ios_base::out);
1415#  endif
1416  _LIBCPP_HIDE_FROM_ABI explicit basic_fstream(const string& __s,
1417                                               ios_base::openmode __mode = ios_base::in | ios_base::out);
1418
1419#  if _LIBCPP_STD_VER >= 17
1420  template <class _Tp, class = enable_if_t<is_same_v<_Tp, filesystem::path>>>
1421  _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY _LIBCPP_HIDE_FROM_ABI explicit basic_fstream(
1422      const _Tp& __p, ios_base::openmode __mode = ios_base::in | ios_base::out)
1423      : basic_fstream(__p.c_str(), __mode) {}
1424#  endif // _LIBCPP_STD_VER >= 17
1425
1426  _LIBCPP_HIDE_FROM_ABI basic_fstream(basic_fstream&& __rhs);
1427
1428  _LIBCPP_HIDE_FROM_ABI basic_fstream& operator=(basic_fstream&& __rhs);
1429
1430  _LIBCPP_HIDE_FROM_ABI void swap(basic_fstream& __rhs);
1431
1432  _LIBCPP_HIDE_FROM_ABI basic_filebuf<char_type, traits_type>* rdbuf() const;
1433#  if _LIBCPP_STD_VER >= 26
1434  _LIBCPP_HIDE_FROM_ABI native_handle_type native_handle() const noexcept { return rdbuf()->native_handle(); }
1435#  endif
1436  _LIBCPP_HIDE_FROM_ABI bool is_open() const;
1437  _LIBCPP_HIDE_FROM_ABI void open(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
1438#  ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1439  void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
1440#  endif
1441  _LIBCPP_HIDE_FROM_ABI void open(const string& __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
1442
1443#  if _LIBCPP_STD_VER >= 17
1444  _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY _LIBCPP_HIDE_FROM_ABI void
1445  open(const filesystem::path& __p, ios_base::openmode __mode = ios_base::in | ios_base::out) {
1446    return open(__p.c_str(), __mode);
1447  }
1448#  endif // _LIBCPP_STD_VER >= 17
1449
1450  _LIBCPP_HIDE_FROM_ABI void close();
1451
1452private:
1453  basic_filebuf<char_type, traits_type> __sb_;
1454};
1455
1456template <class _CharT, class _Traits>
1457inline basic_fstream<_CharT, _Traits>::basic_fstream() : basic_iostream<char_type, traits_type>(&__sb_) {}
1458
1459template <class _CharT, class _Traits>
1460inline basic_fstream<_CharT, _Traits>::basic_fstream(const char* __s, ios_base::openmode __mode)
1461    : basic_iostream<char_type, traits_type>(&__sb_) {
1462  if (__sb_.open(__s, __mode) == nullptr)
1463    this->setstate(ios_base::failbit);
1464}
1465
1466#  ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1467template <class _CharT, class _Traits>
1468inline basic_fstream<_CharT, _Traits>::basic_fstream(const wchar_t* __s, ios_base::openmode __mode)
1469    : basic_iostream<char_type, traits_type>(&__sb_) {
1470  if (__sb_.open(__s, __mode) == nullptr)
1471    this->setstate(ios_base::failbit);
1472}
1473#  endif
1474
1475template <class _CharT, class _Traits>
1476inline basic_fstream<_CharT, _Traits>::basic_fstream(const string& __s, ios_base::openmode __mode)
1477    : basic_iostream<char_type, traits_type>(&__sb_) {
1478  if (__sb_.open(__s, __mode) == nullptr)
1479    this->setstate(ios_base::failbit);
1480}
1481
1482template <class _CharT, class _Traits>
1483inline basic_fstream<_CharT, _Traits>::basic_fstream(basic_fstream&& __rhs)
1484    : basic_iostream<char_type, traits_type>(std::move(__rhs)), __sb_(std::move(__rhs.__sb_)) {
1485  this->set_rdbuf(&__sb_);
1486}
1487
1488template <class _CharT, class _Traits>
1489inline basic_fstream<_CharT, _Traits>& basic_fstream<_CharT, _Traits>::operator=(basic_fstream&& __rhs) {
1490  basic_iostream<char_type, traits_type>::operator=(std::move(__rhs));
1491  __sb_ = std::move(__rhs.__sb_);
1492  return *this;
1493}
1494
1495template <class _CharT, class _Traits>
1496inline void basic_fstream<_CharT, _Traits>::swap(basic_fstream& __rhs) {
1497  basic_iostream<char_type, traits_type>::swap(__rhs);
1498  __sb_.swap(__rhs.__sb_);
1499}
1500
1501template <class _CharT, class _Traits>
1502inline _LIBCPP_HIDE_FROM_ABI void swap(basic_fstream<_CharT, _Traits>& __x, basic_fstream<_CharT, _Traits>& __y) {
1503  __x.swap(__y);
1504}
1505
1506template <class _CharT, class _Traits>
1507inline basic_filebuf<_CharT, _Traits>* basic_fstream<_CharT, _Traits>::rdbuf() const {
1508  return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
1509}
1510
1511template <class _CharT, class _Traits>
1512inline bool basic_fstream<_CharT, _Traits>::is_open() const {
1513  return __sb_.is_open();
1514}
1515
1516template <class _CharT, class _Traits>
1517void basic_fstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode) {
1518  if (__sb_.open(__s, __mode))
1519    this->clear();
1520  else
1521    this->setstate(ios_base::failbit);
1522}
1523
1524#  ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1525template <class _CharT, class _Traits>
1526void basic_fstream<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode) {
1527  if (__sb_.open(__s, __mode))
1528    this->clear();
1529  else
1530    this->setstate(ios_base::failbit);
1531}
1532#  endif
1533
1534template <class _CharT, class _Traits>
1535void basic_fstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode) {
1536  if (__sb_.open(__s, __mode))
1537    this->clear();
1538  else
1539    this->setstate(ios_base::failbit);
1540}
1541
1542template <class _CharT, class _Traits>
1543inline void basic_fstream<_CharT, _Traits>::close() {
1544  if (__sb_.close() == nullptr)
1545    this->setstate(ios_base::failbit);
1546}
1547
1548#  if _LIBCPP_AVAILABILITY_HAS_ADDITIONAL_IOSTREAM_EXPLICIT_INSTANTIATIONS_1
1549extern template class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_ifstream<char>;
1550extern template class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_ofstream<char>;
1551extern template class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_filebuf<char>;
1552#  endif
1553
1554_LIBCPP_END_NAMESPACE_STD
1555
1556#endif // _LIBCPP_HAS_NO_FILESYSTEM
1557
1558_LIBCPP_POP_MACROS
1559
1560#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
1561#  include <atomic>
1562#  include <concepts>
1563#  include <cstdlib>
1564#  include <iosfwd>
1565#  include <limits>
1566#  include <mutex>
1567#  include <new>
1568#  include <stdexcept>
1569#  include <type_traits>
1570#endif
1571
1572#endif // _LIBCPP_FSTREAM
1573