xref: /freebsd/contrib/llvm-project/libcxx/include/fstream (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
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
77    basic_ifstream();
78    explicit basic_ifstream(const char* s, ios_base::openmode mode = ios_base::in);
79    explicit basic_ifstream(const string& s, ios_base::openmode mode = ios_base::in);
80    explicit basic_ifstream(const filesystem::path& p,
81                            ios_base::openmode mode = ios_base::in); // C++17
82    basic_ifstream(basic_ifstream&& rhs);
83
84    basic_ifstream& operator=(basic_ifstream&& rhs);
85    void swap(basic_ifstream& rhs);
86
87    basic_filebuf<char_type, traits_type>* rdbuf() const;
88    bool is_open() const;
89    void open(const char* s, ios_base::openmode mode = ios_base::in);
90    void open(const string& s, ios_base::openmode mode = ios_base::in);
91    void open(const filesystem::path& s, ios_base::openmode mode = ios_base::in); // C++17
92
93    void close();
94};
95
96template <class charT, class traits>
97  void
98  swap(basic_ifstream<charT, traits>& x, basic_ifstream<charT, traits>& y);
99
100typedef basic_ifstream<char>    ifstream;
101typedef basic_ifstream<wchar_t> wifstream;
102
103template <class charT, class traits = char_traits<charT> >
104class basic_ofstream
105    : public basic_ostream<charT,traits>
106{
107public:
108    typedef charT                          char_type;
109    typedef traits                         traits_type;
110    typedef typename traits_type::int_type int_type;
111    typedef typename traits_type::pos_type pos_type;
112    typedef typename traits_type::off_type off_type;
113
114    basic_ofstream();
115    explicit basic_ofstream(const char* s, ios_base::openmode mode = ios_base::out);
116    explicit basic_ofstream(const string& s, ios_base::openmode mode = ios_base::out);
117    explicit basic_ofstream(const filesystem::path& p,
118                            ios_base::openmode mode = ios_base::out); // C++17
119    basic_ofstream(basic_ofstream&& rhs);
120
121    basic_ofstream& operator=(basic_ofstream&& rhs);
122    void swap(basic_ofstream& rhs);
123
124    basic_filebuf<char_type, traits_type>* rdbuf() const;
125    bool is_open() const;
126    void open(const char* s, ios_base::openmode mode = ios_base::out);
127    void open(const string& s, ios_base::openmode mode = ios_base::out);
128    void open(const filesystem::path& p,
129              ios_base::openmode mode = ios_base::out); // C++17
130
131    void close();
132};
133
134template <class charT, class traits>
135  void
136  swap(basic_ofstream<charT, traits>& x, basic_ofstream<charT, traits>& y);
137
138typedef basic_ofstream<char>    ofstream;
139typedef basic_ofstream<wchar_t> wofstream;
140
141template <class charT, class traits=char_traits<charT> >
142class basic_fstream
143    : public basic_iostream<charT,traits>
144{
145public:
146    typedef charT                          char_type;
147    typedef traits                         traits_type;
148    typedef typename traits_type::int_type int_type;
149    typedef typename traits_type::pos_type pos_type;
150    typedef typename traits_type::off_type off_type;
151
152    basic_fstream();
153    explicit basic_fstream(const char* s, ios_base::openmode mode = ios_base::in|ios_base::out);
154    explicit basic_fstream(const string& s, ios_base::openmode mode = ios_base::in|ios_base::out);
155    explicit basic_fstream(const filesystem::path& p,
156                           ios_base::openmode mode = ios_base::in|ios_base::out); C++17
157    basic_fstream(basic_fstream&& rhs);
158
159    basic_fstream& operator=(basic_fstream&& rhs);
160    void swap(basic_fstream& rhs);
161
162    basic_filebuf<char_type, traits_type>* rdbuf() const;
163    bool is_open() const;
164    void open(const char* s, ios_base::openmode mode = ios_base::in|ios_base::out);
165    void open(const string& s, ios_base::openmode mode = ios_base::in|ios_base::out);
166    void open(const filesystem::path& s,
167              ios_base::openmode mode = ios_base::in|ios_base::out); // C++17
168
169    void close();
170};
171
172template <class charT, class traits>
173  void swap(basic_fstream<charT, traits>& x, basic_fstream<charT, traits>& y);
174
175typedef basic_fstream<char>    fstream;
176typedef basic_fstream<wchar_t> wfstream;
177
178}  // std
179
180*/
181
182#include <__algorithm/max.h>
183#include <__assert> // all public C++ headers provide the assertion handler
184#include <__availability>
185#include <__config>
186#include <__fwd/fstream.h>
187#include <__locale>
188#include <__utility/move.h>
189#include <__utility/swap.h>
190#include <__utility/unreachable.h>
191#include <cstdio>
192#include <filesystem>
193#include <istream>
194#include <ostream>
195#include <typeinfo>
196#include <version>
197
198#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
199#  pragma GCC system_header
200#endif
201
202_LIBCPP_PUSH_MACROS
203#include <__undef_macros>
204
205#if defined(_LIBCPP_MSVCRT) || defined(_NEWLIB_VERSION)
206#  define _LIBCPP_HAS_NO_OFF_T_FUNCTIONS
207#endif
208
209#if !defined(_LIBCPP_HAS_NO_FILESYSTEM)
210
211_LIBCPP_BEGIN_NAMESPACE_STD
212
213template <class _CharT, class _Traits>
214class _LIBCPP_TEMPLATE_VIS basic_filebuf
215    : public basic_streambuf<_CharT, _Traits>
216{
217public:
218    typedef _CharT                           char_type;
219    typedef _Traits                          traits_type;
220    typedef typename traits_type::int_type   int_type;
221    typedef typename traits_type::pos_type   pos_type;
222    typedef typename traits_type::off_type   off_type;
223    typedef typename traits_type::state_type state_type;
224
225    // 27.9.1.2 Constructors/destructor:
226    basic_filebuf();
227    basic_filebuf(basic_filebuf&& __rhs);
228    ~basic_filebuf() override;
229
230    // 27.9.1.3 Assign/swap:
231    _LIBCPP_INLINE_VISIBILITY
232    basic_filebuf& operator=(basic_filebuf&& __rhs);
233    void swap(basic_filebuf& __rhs);
234
235    // 27.9.1.4 Members:
236    _LIBCPP_INLINE_VISIBILITY
237    bool is_open() const;
238    basic_filebuf* open(const char* __s, ios_base::openmode __mode);
239#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
240    basic_filebuf* open(const wchar_t* __s, ios_base::openmode __mode);
241#endif
242    _LIBCPP_INLINE_VISIBILITY
243    basic_filebuf* open(const string& __s, ios_base::openmode __mode);
244
245#if _LIBCPP_STD_VER >= 17
246    _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY _LIBCPP_INLINE_VISIBILITY
247    basic_filebuf* open(const _VSTD_FS::path& __p, ios_base::openmode __mode) {
248      return open(__p.c_str(), __mode);
249    }
250#endif
251    _LIBCPP_INLINE_VISIBILITY
252    basic_filebuf* __open(int __fd, ios_base::openmode __mode);
253    basic_filebuf* close();
254
255    _LIBCPP_INLINE_VISIBILITY
256    inline static const char*
257    __make_mdstring(ios_base::openmode __mode) _NOEXCEPT;
258
259  protected:
260    // 27.9.1.5 Overridden virtual functions:
261    int_type underflow() override;
262    int_type pbackfail(int_type __c = traits_type::eof()) override;
263    int_type overflow (int_type __c = traits_type::eof()) override;
264    basic_streambuf<char_type, traits_type>* setbuf(char_type* __s, streamsize __n) override;
265    pos_type seekoff(off_type __off, ios_base::seekdir __way,
266                     ios_base::openmode __wch = ios_base::in | ios_base::out) override;
267    pos_type seekpos(pos_type __sp,
268                     ios_base::openmode __wch = ios_base::in | ios_base::out) override;
269    int sync() override;
270    void imbue(const locale& __loc) override;
271
272private:
273  char* __extbuf_;
274  const char* __extbufnext_;
275  const char* __extbufend_;
276  char __extbuf_min_[8];
277  size_t __ebs_;
278  char_type* __intbuf_;
279  size_t __ibs_;
280  FILE* __file_;
281  const codecvt<char_type, char, state_type>* __cv_;
282  state_type __st_;
283  state_type __st_last_;
284  ios_base::openmode __om_;
285  ios_base::openmode __cm_;
286  bool __owns_eb_;
287  bool __owns_ib_;
288  bool __always_noconv_;
289
290  bool __read_mode();
291  void __write_mode();
292};
293
294template <class _CharT, class _Traits>
295basic_filebuf<_CharT, _Traits>::basic_filebuf()
296    : __extbuf_(nullptr),
297      __extbufnext_(nullptr),
298      __extbufend_(nullptr),
299      __ebs_(0),
300      __intbuf_(nullptr),
301      __ibs_(0),
302      __file_(nullptr),
303      __cv_(nullptr),
304      __st_(),
305      __st_last_(),
306      __om_(0),
307      __cm_(0),
308      __owns_eb_(false),
309      __owns_ib_(false),
310      __always_noconv_(false)
311{
312    if (std::has_facet<codecvt<char_type, char, state_type> >(this->getloc()))
313    {
314        __cv_ = &std::use_facet<codecvt<char_type, char, state_type> >(this->getloc());
315        __always_noconv_ = __cv_->always_noconv();
316    }
317    setbuf(nullptr, 4096);
318}
319
320template <class _CharT, class _Traits>
321basic_filebuf<_CharT, _Traits>::basic_filebuf(basic_filebuf&& __rhs)
322    : basic_streambuf<_CharT, _Traits>(__rhs)
323{
324    if (__rhs.__extbuf_ == __rhs.__extbuf_min_)
325    {
326        __extbuf_ = __extbuf_min_;
327        __extbufnext_ = __extbuf_ + (__rhs.__extbufnext_ - __rhs.__extbuf_);
328        __extbufend_ = __extbuf_ + (__rhs.__extbufend_ - __rhs.__extbuf_);
329    }
330    else
331    {
332        __extbuf_ = __rhs.__extbuf_;
333        __extbufnext_ = __rhs.__extbufnext_;
334        __extbufend_ = __rhs.__extbufend_;
335    }
336    __ebs_ = __rhs.__ebs_;
337    __intbuf_ = __rhs.__intbuf_;
338    __ibs_ = __rhs.__ibs_;
339    __file_ = __rhs.__file_;
340    __cv_ = __rhs.__cv_;
341    __st_ = __rhs.__st_;
342    __st_last_ = __rhs.__st_last_;
343    __om_ = __rhs.__om_;
344    __cm_ = __rhs.__cm_;
345    __owns_eb_ = __rhs.__owns_eb_;
346    __owns_ib_ = __rhs.__owns_ib_;
347    __always_noconv_ = __rhs.__always_noconv_;
348    if (__rhs.pbase())
349    {
350        if (__rhs.pbase() == __rhs.__intbuf_)
351            this->setp(__intbuf_, __intbuf_ + (__rhs. epptr() - __rhs.pbase()));
352        else
353            this->setp((char_type*)__extbuf_,
354                       (char_type*)__extbuf_ + (__rhs. epptr() - __rhs.pbase()));
355        this->__pbump(__rhs. pptr() - __rhs.pbase());
356    }
357    else if (__rhs.eback())
358    {
359        if (__rhs.eback() == __rhs.__intbuf_)
360            this->setg(__intbuf_, __intbuf_ + (__rhs.gptr() - __rhs.eback()),
361                                  __intbuf_ + (__rhs.egptr() - __rhs.eback()));
362        else
363            this->setg((char_type*)__extbuf_,
364                       (char_type*)__extbuf_ + (__rhs.gptr() - __rhs.eback()),
365                       (char_type*)__extbuf_ + (__rhs.egptr() - __rhs.eback()));
366    }
367    __rhs.__extbuf_ = nullptr;
368    __rhs.__extbufnext_ = nullptr;
369    __rhs.__extbufend_ = nullptr;
370    __rhs.__ebs_ = 0;
371    __rhs.__intbuf_ = 0;
372    __rhs.__ibs_ = 0;
373    __rhs.__file_ = nullptr;
374    __rhs.__st_ = state_type();
375    __rhs.__st_last_ = state_type();
376    __rhs.__om_ = 0;
377    __rhs.__cm_ = 0;
378    __rhs.__owns_eb_ = false;
379    __rhs.__owns_ib_ = false;
380    __rhs.setg(0, 0, 0);
381    __rhs.setp(0, 0);
382}
383
384template <class _CharT, class _Traits>
385inline
386basic_filebuf<_CharT, _Traits>&
387basic_filebuf<_CharT, _Traits>::operator=(basic_filebuf&& __rhs)
388{
389    close();
390    swap(__rhs);
391    return *this;
392}
393
394template <class _CharT, class _Traits>
395basic_filebuf<_CharT, _Traits>::~basic_filebuf()
396{
397#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
398    try
399    {
400#endif // _LIBCPP_HAS_NO_EXCEPTIONS
401        close();
402#ifndef _LIBCPP_HAS_NO_EXCEPTIONS
403    }
404    catch (...)
405    {
406    }
407#endif // _LIBCPP_HAS_NO_EXCEPTIONS
408    if (__owns_eb_)
409        delete [] __extbuf_;
410    if (__owns_ib_)
411        delete [] __intbuf_;
412}
413
414template <class _CharT, class _Traits>
415void
416basic_filebuf<_CharT, _Traits>::swap(basic_filebuf& __rhs)
417{
418    basic_streambuf<char_type, traits_type>::swap(__rhs);
419    if (__extbuf_ != __extbuf_min_ && __rhs.__extbuf_ != __rhs.__extbuf_min_)
420    {
421        // Neither *this nor __rhs uses the small buffer, so we can simply swap the pointers.
422        std::swap(__extbuf_, __rhs.__extbuf_);
423        std::swap(__extbufnext_, __rhs.__extbufnext_);
424        std::swap(__extbufend_, __rhs.__extbufend_);
425    }
426    else
427    {
428        ptrdiff_t __ln = __extbufnext_       ? __extbufnext_ - __extbuf_             : 0;
429        ptrdiff_t __le = __extbufend_        ? __extbufend_ - __extbuf_              : 0;
430        ptrdiff_t __rn = __rhs.__extbufnext_ ? __rhs.__extbufnext_ - __rhs.__extbuf_ : 0;
431        ptrdiff_t __re = __rhs.__extbufend_  ? __rhs.__extbufend_ - __rhs.__extbuf_  : 0;
432        if (__extbuf_ == __extbuf_min_ && __rhs.__extbuf_ != __rhs.__extbuf_min_)
433        {
434            // *this uses the small buffer, but __rhs doesn't.
435            __extbuf_ = __rhs.__extbuf_;
436            __rhs.__extbuf_ = __rhs.__extbuf_min_;
437            std::memmove(__rhs.__extbuf_min_, __extbuf_min_, sizeof(__extbuf_min_));
438        }
439        else if (__extbuf_ != __extbuf_min_ && __rhs.__extbuf_ == __rhs.__extbuf_min_)
440        {
441            // *this doesn't use the small buffer, but __rhs does.
442            __rhs.__extbuf_ = __extbuf_;
443            __extbuf_ = __extbuf_min_;
444            std::memmove(__extbuf_min_, __rhs.__extbuf_min_, sizeof(__extbuf_min_));
445        }
446        else
447        {
448            // Both *this and __rhs use the small buffer.
449            char __tmp[sizeof(__extbuf_min_)];
450            std::memmove(__tmp, __extbuf_min_, sizeof(__extbuf_min_));
451            std::memmove(__extbuf_min_, __rhs.__extbuf_min_, sizeof(__extbuf_min_));
452            std::memmove(__rhs.__extbuf_min_, __tmp, sizeof(__extbuf_min_));
453        }
454        __extbufnext_ = __extbuf_ + __rn;
455        __extbufend_ = __extbuf_ + __re;
456        __rhs.__extbufnext_ = __rhs.__extbuf_ + __ln;
457        __rhs.__extbufend_ = __rhs.__extbuf_ + __le;
458    }
459    _VSTD::swap(__ebs_, __rhs.__ebs_);
460    _VSTD::swap(__intbuf_, __rhs.__intbuf_);
461    _VSTD::swap(__ibs_, __rhs.__ibs_);
462    _VSTD::swap(__file_, __rhs.__file_);
463    _VSTD::swap(__cv_, __rhs.__cv_);
464    _VSTD::swap(__st_, __rhs.__st_);
465    _VSTD::swap(__st_last_, __rhs.__st_last_);
466    _VSTD::swap(__om_, __rhs.__om_);
467    _VSTD::swap(__cm_, __rhs.__cm_);
468    _VSTD::swap(__owns_eb_, __rhs.__owns_eb_);
469    _VSTD::swap(__owns_ib_, __rhs.__owns_ib_);
470    _VSTD::swap(__always_noconv_, __rhs.__always_noconv_);
471    if (this->eback() == (char_type*)__rhs.__extbuf_min_)
472    {
473        ptrdiff_t __n = this->gptr() - this->eback();
474        ptrdiff_t __e = this->egptr() - this->eback();
475        this->setg((char_type*)__extbuf_min_,
476                   (char_type*)__extbuf_min_ + __n,
477                   (char_type*)__extbuf_min_ + __e);
478    }
479    else if (this->pbase() == (char_type*)__rhs.__extbuf_min_)
480    {
481        ptrdiff_t __n = this->pptr() - this->pbase();
482        ptrdiff_t __e = this->epptr() - this->pbase();
483        this->setp((char_type*)__extbuf_min_,
484                   (char_type*)__extbuf_min_ + __e);
485        this->__pbump(__n);
486    }
487    if (__rhs.eback() == (char_type*)__extbuf_min_)
488    {
489        ptrdiff_t __n = __rhs.gptr() - __rhs.eback();
490        ptrdiff_t __e = __rhs.egptr() - __rhs.eback();
491        __rhs.setg((char_type*)__rhs.__extbuf_min_,
492                   (char_type*)__rhs.__extbuf_min_ + __n,
493                   (char_type*)__rhs.__extbuf_min_ + __e);
494    }
495    else if (__rhs.pbase() == (char_type*)__extbuf_min_)
496    {
497        ptrdiff_t __n = __rhs.pptr() - __rhs.pbase();
498        ptrdiff_t __e = __rhs.epptr() - __rhs.pbase();
499        __rhs.setp((char_type*)__rhs.__extbuf_min_,
500                   (char_type*)__rhs.__extbuf_min_ + __e);
501        __rhs.__pbump(__n);
502    }
503}
504
505template <class _CharT, class _Traits>
506inline _LIBCPP_INLINE_VISIBILITY
507void
508swap(basic_filebuf<_CharT, _Traits>& __x, basic_filebuf<_CharT, _Traits>& __y)
509{
510    __x.swap(__y);
511}
512
513template <class _CharT, class _Traits>
514inline
515bool
516basic_filebuf<_CharT, _Traits>::is_open() const
517{
518    return __file_ != nullptr;
519}
520
521template <class _CharT, class _Traits>
522const char* basic_filebuf<_CharT, _Traits>::__make_mdstring(
523    ios_base::openmode __mode) _NOEXCEPT {
524  switch (__mode & ~ios_base::ate) {
525  case ios_base::out:
526  case ios_base::out | ios_base::trunc:
527    return "w" _LIBCPP_FOPEN_CLOEXEC_MODE;
528  case ios_base::out | ios_base::app:
529  case ios_base::app:
530    return "a" _LIBCPP_FOPEN_CLOEXEC_MODE;
531  case ios_base::in:
532    return "r" _LIBCPP_FOPEN_CLOEXEC_MODE;
533  case ios_base::in | ios_base::out:
534    return "r+" _LIBCPP_FOPEN_CLOEXEC_MODE;
535  case ios_base::in | ios_base::out | ios_base::trunc:
536    return "w+" _LIBCPP_FOPEN_CLOEXEC_MODE;
537  case ios_base::in | ios_base::out | ios_base::app:
538  case ios_base::in | ios_base::app:
539    return "a+" _LIBCPP_FOPEN_CLOEXEC_MODE;
540  case ios_base::out | ios_base::binary:
541  case ios_base::out | ios_base::trunc | ios_base::binary:
542    return "wb" _LIBCPP_FOPEN_CLOEXEC_MODE;
543  case ios_base::out | ios_base::app | ios_base::binary:
544  case ios_base::app | ios_base::binary:
545    return "ab" _LIBCPP_FOPEN_CLOEXEC_MODE;
546  case ios_base::in | ios_base::binary:
547    return "rb" _LIBCPP_FOPEN_CLOEXEC_MODE;
548  case ios_base::in | ios_base::out | ios_base::binary:
549    return "r+b" _LIBCPP_FOPEN_CLOEXEC_MODE;
550  case ios_base::in | ios_base::out | ios_base::trunc | ios_base::binary:
551    return "w+b" _LIBCPP_FOPEN_CLOEXEC_MODE;
552  case ios_base::in | ios_base::out | ios_base::app | ios_base::binary:
553  case ios_base::in | ios_base::app | ios_base::binary:
554    return "a+b" _LIBCPP_FOPEN_CLOEXEC_MODE;
555  default:
556    return nullptr;
557  }
558  __libcpp_unreachable();
559}
560
561template <class _CharT, class _Traits>
562basic_filebuf<_CharT, _Traits>*
563basic_filebuf<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
564{
565    basic_filebuf<_CharT, _Traits>* __rt = nullptr;
566    if (__file_ == nullptr)
567    {
568      if (const char* __mdstr = __make_mdstring(__mode)) {
569        __rt = this;
570        __file_ = fopen(__s, __mdstr);
571        if (__file_) {
572          __om_ = __mode;
573          if (__mode & ios_base::ate) {
574            if (fseek(__file_, 0, SEEK_END)) {
575              fclose(__file_);
576              __file_ = nullptr;
577              __rt = nullptr;
578            }
579          }
580        } else
581          __rt = nullptr;
582      }
583    }
584    return __rt;
585}
586
587template <class _CharT, class _Traits>
588inline
589basic_filebuf<_CharT, _Traits>*
590basic_filebuf<_CharT, _Traits>::__open(int __fd, ios_base::openmode __mode) {
591  basic_filebuf<_CharT, _Traits>* __rt = nullptr;
592  if (__file_ == nullptr) {
593    if (const char* __mdstr = __make_mdstring(__mode)) {
594      __rt = this;
595      __file_ = fdopen(__fd, __mdstr);
596      if (__file_) {
597        __om_ = __mode;
598        if (__mode & ios_base::ate) {
599          if (fseek(__file_, 0, SEEK_END)) {
600            fclose(__file_);
601            __file_ = nullptr;
602            __rt = nullptr;
603          }
604        }
605      } else
606        __rt = nullptr;
607    }
608  }
609  return __rt;
610}
611
612#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
613// This is basically the same as the char* overload except that it uses _wfopen
614// and long mode strings.
615template <class _CharT, class _Traits>
616basic_filebuf<_CharT, _Traits>*
617basic_filebuf<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode)
618{
619    basic_filebuf<_CharT, _Traits>* __rt = nullptr;
620    if (__file_ == nullptr)
621    {
622        __rt = this;
623        const wchar_t* __mdstr;
624        switch (__mode & ~ios_base::ate)
625        {
626        case ios_base::out:
627        case ios_base::out | ios_base::trunc:
628            __mdstr = L"w";
629            break;
630        case ios_base::out | ios_base::app:
631        case ios_base::app:
632            __mdstr = L"a";
633            break;
634        case ios_base::in:
635            __mdstr = L"r";
636            break;
637        case ios_base::in | ios_base::out:
638            __mdstr = L"r+";
639            break;
640        case ios_base::in | ios_base::out | ios_base::trunc:
641            __mdstr = L"w+";
642            break;
643        case ios_base::in | ios_base::out | ios_base::app:
644        case ios_base::in | ios_base::app:
645            __mdstr = L"a+";
646            break;
647        case ios_base::out | ios_base::binary:
648        case ios_base::out | ios_base::trunc | ios_base::binary:
649            __mdstr = L"wb";
650            break;
651        case ios_base::out | ios_base::app | ios_base::binary:
652        case ios_base::app | ios_base::binary:
653            __mdstr = L"ab";
654            break;
655        case ios_base::in | ios_base::binary:
656            __mdstr = L"rb";
657            break;
658        case ios_base::in | ios_base::out | ios_base::binary:
659            __mdstr = L"r+b";
660            break;
661        case ios_base::in | ios_base::out | ios_base::trunc | ios_base::binary:
662            __mdstr = L"w+b";
663            break;
664        case ios_base::in | ios_base::out | ios_base::app | ios_base::binary:
665        case ios_base::in | ios_base::app | ios_base::binary:
666            __mdstr = L"a+b";
667            break;
668        default:
669            __rt = nullptr;
670            break;
671        }
672        if (__rt)
673        {
674            __file_ = _wfopen(__s, __mdstr);
675            if (__file_)
676            {
677                __om_ = __mode;
678                if (__mode & ios_base::ate)
679                {
680                    if (fseek(__file_, 0, SEEK_END))
681                    {
682                        fclose(__file_);
683                        __file_ = nullptr;
684                        __rt = nullptr;
685                    }
686                }
687            }
688            else
689                __rt = nullptr;
690        }
691    }
692    return __rt;
693}
694#endif
695
696template <class _CharT, class _Traits>
697inline
698basic_filebuf<_CharT, _Traits>*
699basic_filebuf<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
700{
701    return open(__s.c_str(), __mode);
702}
703
704template <class _CharT, class _Traits>
705basic_filebuf<_CharT, _Traits>*
706basic_filebuf<_CharT, _Traits>::close()
707{
708    basic_filebuf<_CharT, _Traits>* __rt = nullptr;
709    if (__file_)
710    {
711        __rt = this;
712        unique_ptr<FILE, int(*)(FILE*)> __h(__file_, fclose);
713        if (sync())
714            __rt = nullptr;
715        if (fclose(__h.release()))
716            __rt = nullptr;
717        __file_ = nullptr;
718        setbuf(0, 0);
719    }
720    return __rt;
721}
722
723template <class _CharT, class _Traits>
724typename basic_filebuf<_CharT, _Traits>::int_type
725basic_filebuf<_CharT, _Traits>::underflow()
726{
727    if (__file_ == nullptr)
728        return traits_type::eof();
729    bool __initial = __read_mode();
730    char_type __1buf;
731    if (this->gptr() == nullptr)
732        this->setg(&__1buf, &__1buf+1, &__1buf+1);
733    const size_t __unget_sz = __initial ? 0 : std::min<size_t>((this->egptr() - this->eback()) / 2, 4);
734    int_type __c = traits_type::eof();
735    if (this->gptr() == this->egptr())
736    {
737        _VSTD::memmove(this->eback(), this->egptr() - __unget_sz, __unget_sz * sizeof(char_type));
738        if (__always_noconv_)
739        {
740            size_t __nmemb = static_cast<size_t>(this->egptr() - this->eback() - __unget_sz);
741            __nmemb = ::fread(this->eback() + __unget_sz, 1, __nmemb, __file_);
742            if (__nmemb != 0)
743            {
744                this->setg(this->eback(),
745                           this->eback() + __unget_sz,
746                           this->eback() + __unget_sz + __nmemb);
747                __c = traits_type::to_int_type(*this->gptr());
748            }
749        }
750        else
751        {
752            if (__extbufend_ != __extbufnext_) {
753                _LIBCPP_ASSERT_UNCATEGORIZED(__extbufnext_ != nullptr, "underflow moving from nullptr");
754                _LIBCPP_ASSERT_UNCATEGORIZED(__extbuf_ != nullptr, "underflow moving into nullptr");
755                _VSTD::memmove(__extbuf_, __extbufnext_, __extbufend_ - __extbufnext_);
756            }
757            __extbufnext_ = __extbuf_ + (__extbufend_ - __extbufnext_);
758            __extbufend_ = __extbuf_ + (__extbuf_ == __extbuf_min_ ? sizeof(__extbuf_min_) : __ebs_);
759            size_t __nmemb = _VSTD::min(static_cast<size_t>(__ibs_ - __unget_sz),
760                                 static_cast<size_t>(__extbufend_ - __extbufnext_));
761            codecvt_base::result __r;
762            __st_last_ = __st_;
763            size_t __nr = fread((void*) const_cast<char *>(__extbufnext_), 1, __nmemb, __file_);
764            if (__nr != 0)
765            {
766                if (!__cv_)
767                    __throw_bad_cast();
768
769                __extbufend_ = __extbufnext_ + __nr;
770                char_type*  __inext;
771                __r = __cv_->in(__st_, __extbuf_, __extbufend_, __extbufnext_,
772                                       this->eback() + __unget_sz,
773                                       this->eback() + __ibs_, __inext);
774                if (__r == codecvt_base::noconv)
775                {
776                    this->setg((char_type*)__extbuf_, (char_type*)__extbuf_,
777                                          (char_type*)const_cast<char *>(__extbufend_));
778                    __c = traits_type::to_int_type(*this->gptr());
779                }
780                else if (__inext != this->eback() + __unget_sz)
781                {
782                    this->setg(this->eback(), this->eback() + __unget_sz, __inext);
783                    __c = traits_type::to_int_type(*this->gptr());
784                }
785            }
786        }
787    }
788    else
789        __c = traits_type::to_int_type(*this->gptr());
790    if (this->eback() == &__1buf)
791        this->setg(nullptr, nullptr, nullptr);
792    return __c;
793}
794
795template <class _CharT, class _Traits>
796typename basic_filebuf<_CharT, _Traits>::int_type
797basic_filebuf<_CharT, _Traits>::pbackfail(int_type __c)
798{
799    if (__file_ && this->eback() < this->gptr())
800    {
801        if (traits_type::eq_int_type(__c, traits_type::eof()))
802        {
803            this->gbump(-1);
804            return traits_type::not_eof(__c);
805        }
806        if ((__om_ & ios_base::out) ||
807            traits_type::eq(traits_type::to_char_type(__c), this->gptr()[-1]))
808        {
809            this->gbump(-1);
810            *this->gptr() = traits_type::to_char_type(__c);
811            return __c;
812        }
813    }
814    return traits_type::eof();
815}
816
817template <class _CharT, class _Traits>
818typename basic_filebuf<_CharT, _Traits>::int_type
819basic_filebuf<_CharT, _Traits>::overflow(int_type __c)
820{
821    if (__file_ == nullptr)
822        return traits_type::eof();
823    __write_mode();
824    char_type __1buf;
825    char_type* __pb_save = this->pbase();
826    char_type* __epb_save = this->epptr();
827    if (!traits_type::eq_int_type(__c, traits_type::eof()))
828    {
829        if (this->pptr() == nullptr)
830            this->setp(&__1buf, &__1buf+1);
831        *this->pptr() = traits_type::to_char_type(__c);
832        this->pbump(1);
833    }
834    if (this->pptr() != this->pbase())
835    {
836        if (__always_noconv_)
837        {
838            size_t __nmemb = static_cast<size_t>(this->pptr() - this->pbase());
839            if (std::fwrite(this->pbase(), sizeof(char_type), __nmemb, __file_) != __nmemb)
840                return traits_type::eof();
841        }
842        else
843        {
844            char* __extbe = __extbuf_;
845            codecvt_base::result __r;
846            do
847            {
848                if (!__cv_)
849                    __throw_bad_cast();
850
851                const char_type* __e;
852                __r = __cv_->out(__st_, this->pbase(), this->pptr(), __e,
853                                        __extbuf_, __extbuf_ + __ebs_, __extbe);
854                if (__e == this->pbase())
855                    return traits_type::eof();
856                if (__r == codecvt_base::noconv)
857                {
858                    size_t __nmemb = static_cast<size_t>(this->pptr() - this->pbase());
859                    if (std::fwrite(this->pbase(), 1, __nmemb, __file_) != __nmemb)
860                        return traits_type::eof();
861                }
862                else if (__r == codecvt_base::ok || __r == codecvt_base::partial)
863                {
864                    size_t __nmemb = static_cast<size_t>(__extbe - __extbuf_);
865                    if (fwrite(__extbuf_, 1, __nmemb, __file_) != __nmemb)
866                        return traits_type::eof();
867                    if (__r == codecvt_base::partial)
868                    {
869                        this->setp(const_cast<char_type*>(__e), this->pptr());
870                        this->__pbump(this->epptr() - this->pbase());
871                    }
872                }
873                else
874                    return traits_type::eof();
875            } while (__r == codecvt_base::partial);
876        }
877        this->setp(__pb_save, __epb_save);
878    }
879    return traits_type::not_eof(__c);
880}
881
882template <class _CharT, class _Traits>
883basic_streambuf<_CharT, _Traits>*
884basic_filebuf<_CharT, _Traits>::setbuf(char_type* __s, streamsize __n)
885{
886    this->setg(nullptr, nullptr, nullptr);
887    this->setp(nullptr, nullptr);
888    if (__owns_eb_)
889        delete [] __extbuf_;
890    if (__owns_ib_)
891        delete [] __intbuf_;
892    __ebs_ = __n;
893    if (__ebs_ > sizeof(__extbuf_min_))
894    {
895        if (__always_noconv_ && __s)
896        {
897            __extbuf_ = (char*)__s;
898            __owns_eb_ = false;
899        }
900        else
901        {
902            __extbuf_ = new char[__ebs_];
903            __owns_eb_ = true;
904        }
905    }
906    else
907    {
908        __extbuf_ = __extbuf_min_;
909        __ebs_ = sizeof(__extbuf_min_);
910        __owns_eb_ = false;
911    }
912    if (!__always_noconv_)
913    {
914        __ibs_ = max<streamsize>(__n, sizeof(__extbuf_min_));
915        if (__s && __ibs_ >= sizeof(__extbuf_min_))
916        {
917            __intbuf_ = __s;
918            __owns_ib_ = false;
919        }
920        else
921        {
922            __intbuf_ = new char_type[__ibs_];
923            __owns_ib_ = true;
924        }
925    }
926    else
927    {
928        __ibs_ = 0;
929        __intbuf_ = nullptr;
930        __owns_ib_ = false;
931    }
932    return this;
933}
934
935template <class _CharT, class _Traits>
936typename basic_filebuf<_CharT, _Traits>::pos_type
937basic_filebuf<_CharT, _Traits>::seekoff(off_type __off, ios_base::seekdir __way,
938                                        ios_base::openmode)
939{
940    if (!__cv_)
941        __throw_bad_cast();
942
943    int __width = __cv_->encoding();
944    if (__file_ == nullptr || (__width <= 0 && __off != 0) || sync())
945        return pos_type(off_type(-1));
946    // __width > 0 || __off == 0
947    int __whence;
948    switch (__way)
949    {
950    case ios_base::beg:
951        __whence = SEEK_SET;
952        break;
953    case ios_base::cur:
954        __whence = SEEK_CUR;
955        break;
956    case ios_base::end:
957        __whence = SEEK_END;
958        break;
959    default:
960        return pos_type(off_type(-1));
961    }
962#if defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
963    if (fseek(__file_, __width > 0 ? __width * __off : 0, __whence))
964        return pos_type(off_type(-1));
965    pos_type __r = ftell(__file_);
966#else
967    if (::fseeko(__file_, __width > 0 ? __width * __off : 0, __whence))
968        return pos_type(off_type(-1));
969    pos_type __r = ftello(__file_);
970#endif
971    __r.state(__st_);
972    return __r;
973}
974
975template <class _CharT, class _Traits>
976typename basic_filebuf<_CharT, _Traits>::pos_type
977basic_filebuf<_CharT, _Traits>::seekpos(pos_type __sp, ios_base::openmode)
978{
979    if (__file_ == nullptr || sync())
980        return pos_type(off_type(-1));
981#if defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
982    if (fseek(__file_, __sp, SEEK_SET))
983        return pos_type(off_type(-1));
984#else
985    if (::fseeko(__file_, __sp, SEEK_SET))
986        return pos_type(off_type(-1));
987#endif
988    __st_ = __sp.state();
989    return __sp;
990}
991
992template <class _CharT, class _Traits>
993int
994basic_filebuf<_CharT, _Traits>::sync()
995{
996    if (__file_ == nullptr)
997        return 0;
998    if (!__cv_)
999        __throw_bad_cast();
1000
1001    if (__cm_ & ios_base::out)
1002    {
1003        if (this->pptr() != this->pbase())
1004            if (overflow() == traits_type::eof())
1005                return -1;
1006        codecvt_base::result __r;
1007        do
1008        {
1009            char* __extbe;
1010            __r = __cv_->unshift(__st_, __extbuf_, __extbuf_ + __ebs_, __extbe);
1011            size_t __nmemb = static_cast<size_t>(__extbe - __extbuf_);
1012            if (fwrite(__extbuf_, 1, __nmemb, __file_) != __nmemb)
1013                return -1;
1014        } while (__r == codecvt_base::partial);
1015        if (__r == codecvt_base::error)
1016            return -1;
1017        if (fflush(__file_))
1018            return -1;
1019    }
1020    else if (__cm_ & ios_base::in)
1021    {
1022        off_type __c;
1023        state_type __state = __st_last_;
1024        bool __update_st = false;
1025        if (__always_noconv_)
1026            __c = this->egptr() - this->gptr();
1027        else
1028        {
1029            int __width = __cv_->encoding();
1030            __c = __extbufend_ - __extbufnext_;
1031            if (__width > 0)
1032                __c += __width * (this->egptr() - this->gptr());
1033            else
1034            {
1035                if (this->gptr() != this->egptr())
1036                {
1037                    const int __off =  __cv_->length(__state, __extbuf_,
1038                                                     __extbufnext_,
1039                                                     this->gptr() - this->eback());
1040                    __c += __extbufnext_ - __extbuf_ - __off;
1041                    __update_st = true;
1042                }
1043            }
1044        }
1045#if defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
1046        if (fseek(__file_, -__c, SEEK_CUR))
1047            return -1;
1048#else
1049        if (::fseeko(__file_, -__c, SEEK_CUR))
1050            return -1;
1051#endif
1052        if (__update_st)
1053            __st_ = __state;
1054        __extbufnext_ = __extbufend_ = __extbuf_;
1055        this->setg(nullptr, nullptr, nullptr);
1056        __cm_ = 0;
1057    }
1058    return 0;
1059}
1060
1061template <class _CharT, class _Traits>
1062void
1063basic_filebuf<_CharT, _Traits>::imbue(const locale& __loc)
1064{
1065    sync();
1066    __cv_ = &std::use_facet<codecvt<char_type, char, state_type> >(__loc);
1067    bool __old_anc = __always_noconv_;
1068    __always_noconv_ = __cv_->always_noconv();
1069    if (__old_anc != __always_noconv_)
1070    {
1071        this->setg(nullptr, nullptr, nullptr);
1072        this->setp(nullptr, nullptr);
1073        // invariant, char_type is char, else we couldn't get here
1074        if (__always_noconv_)  // need to dump __intbuf_
1075        {
1076            if (__owns_eb_)
1077                delete [] __extbuf_;
1078            __owns_eb_ = __owns_ib_;
1079            __ebs_ = __ibs_;
1080            __extbuf_ = (char*)__intbuf_;
1081            __ibs_ = 0;
1082            __intbuf_ = nullptr;
1083            __owns_ib_ = false;
1084        }
1085        else  // need to obtain an __intbuf_.
1086        {     // If __extbuf_ is user-supplied, use it, else new __intbuf_
1087            if (!__owns_eb_ && __extbuf_ != __extbuf_min_)
1088            {
1089                __ibs_ = __ebs_;
1090                __intbuf_ = (char_type*)__extbuf_;
1091                __owns_ib_ = false;
1092                __extbuf_ = new char[__ebs_];
1093                __owns_eb_ = true;
1094            }
1095            else
1096            {
1097                __ibs_ = __ebs_;
1098                __intbuf_ = new char_type[__ibs_];
1099                __owns_ib_ = true;
1100            }
1101        }
1102    }
1103}
1104
1105template <class _CharT, class _Traits>
1106bool
1107basic_filebuf<_CharT, _Traits>::__read_mode()
1108{
1109    if (!(__cm_ & ios_base::in))
1110    {
1111        this->setp(nullptr, nullptr);
1112        if (__always_noconv_)
1113            this->setg((char_type*)__extbuf_,
1114                       (char_type*)__extbuf_ + __ebs_,
1115                       (char_type*)__extbuf_ + __ebs_);
1116        else
1117            this->setg(__intbuf_, __intbuf_ + __ibs_, __intbuf_ + __ibs_);
1118        __cm_ = ios_base::in;
1119        return true;
1120    }
1121    return false;
1122}
1123
1124template <class _CharT, class _Traits>
1125void
1126basic_filebuf<_CharT, _Traits>::__write_mode()
1127{
1128    if (!(__cm_ & ios_base::out))
1129    {
1130        this->setg(nullptr, nullptr, nullptr);
1131        if (__ebs_ > sizeof(__extbuf_min_))
1132        {
1133            if (__always_noconv_)
1134                this->setp((char_type*)__extbuf_,
1135                           (char_type*)__extbuf_ + (__ebs_ - 1));
1136            else
1137                this->setp(__intbuf_, __intbuf_ + (__ibs_ - 1));
1138        }
1139        else
1140            this->setp(nullptr, nullptr);
1141        __cm_ = ios_base::out;
1142    }
1143}
1144
1145// basic_ifstream
1146
1147template <class _CharT, class _Traits>
1148class _LIBCPP_TEMPLATE_VIS basic_ifstream
1149    : public basic_istream<_CharT, _Traits>
1150{
1151public:
1152    typedef _CharT                         char_type;
1153    typedef _Traits                        traits_type;
1154    typedef typename traits_type::int_type int_type;
1155    typedef typename traits_type::pos_type pos_type;
1156    typedef typename traits_type::off_type off_type;
1157
1158    _LIBCPP_INLINE_VISIBILITY
1159    basic_ifstream();
1160    _LIBCPP_INLINE_VISIBILITY
1161    explicit basic_ifstream(const char* __s, ios_base::openmode __mode = ios_base::in);
1162#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1163    _LIBCPP_INLINE_VISIBILITY
1164    explicit basic_ifstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::in);
1165#endif
1166    _LIBCPP_INLINE_VISIBILITY
1167    explicit basic_ifstream(const string& __s, ios_base::openmode __mode = ios_base::in);
1168#if _LIBCPP_STD_VER >= 17
1169    _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY _LIBCPP_INLINE_VISIBILITY
1170    explicit basic_ifstream(const filesystem::path& __p, ios_base::openmode __mode = ios_base::in)
1171      : basic_ifstream(__p.c_str(), __mode) {}
1172#endif // _LIBCPP_STD_VER >= 17
1173    _LIBCPP_INLINE_VISIBILITY
1174    basic_ifstream(basic_ifstream&& __rhs);
1175    _LIBCPP_INLINE_VISIBILITY
1176    basic_ifstream& operator=(basic_ifstream&& __rhs);
1177    _LIBCPP_INLINE_VISIBILITY
1178    void swap(basic_ifstream& __rhs);
1179
1180    _LIBCPP_INLINE_VISIBILITY
1181    basic_filebuf<char_type, traits_type>* rdbuf() const;
1182    _LIBCPP_INLINE_VISIBILITY
1183    bool is_open() const;
1184    void open(const char* __s, ios_base::openmode __mode = ios_base::in);
1185#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1186    void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::in);
1187#endif
1188    void open(const string& __s, ios_base::openmode __mode = ios_base::in);
1189#if _LIBCPP_STD_VER >= 17
1190    _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY _LIBCPP_INLINE_VISIBILITY
1191    void open(const filesystem::path& __p,
1192              ios_base::openmode __mode = ios_base::in) {
1193      return open(__p.c_str(), __mode);
1194    }
1195#endif // _LIBCPP_STD_VER >= 17
1196
1197    _LIBCPP_INLINE_VISIBILITY
1198    void __open(int __fd, ios_base::openmode __mode);
1199    _LIBCPP_INLINE_VISIBILITY
1200    void close();
1201
1202private:
1203    basic_filebuf<char_type, traits_type> __sb_;
1204};
1205
1206template <class _CharT, class _Traits>
1207inline
1208basic_ifstream<_CharT, _Traits>::basic_ifstream()
1209    : basic_istream<char_type, traits_type>(&__sb_)
1210{
1211}
1212
1213template <class _CharT, class _Traits>
1214inline
1215basic_ifstream<_CharT, _Traits>::basic_ifstream(const char* __s, ios_base::openmode __mode)
1216    : basic_istream<char_type, traits_type>(&__sb_)
1217{
1218    if (__sb_.open(__s, __mode | ios_base::in) == nullptr)
1219        this->setstate(ios_base::failbit);
1220}
1221
1222#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1223template <class _CharT, class _Traits>
1224inline
1225basic_ifstream<_CharT, _Traits>::basic_ifstream(const wchar_t* __s, ios_base::openmode __mode)
1226    : basic_istream<char_type, traits_type>(&__sb_)
1227{
1228    if (__sb_.open(__s, __mode | ios_base::in) == nullptr)
1229        this->setstate(ios_base::failbit);
1230}
1231#endif
1232
1233template <class _CharT, class _Traits>
1234inline
1235basic_ifstream<_CharT, _Traits>::basic_ifstream(const string& __s, ios_base::openmode __mode)
1236    : basic_istream<char_type, traits_type>(&__sb_)
1237{
1238    if (__sb_.open(__s, __mode | ios_base::in) == nullptr)
1239        this->setstate(ios_base::failbit);
1240}
1241
1242template <class _CharT, class _Traits>
1243inline
1244basic_ifstream<_CharT, _Traits>::basic_ifstream(basic_ifstream&& __rhs)
1245    : basic_istream<char_type, traits_type>(_VSTD::move(__rhs)),
1246      __sb_(_VSTD::move(__rhs.__sb_))
1247{
1248    this->set_rdbuf(&__sb_);
1249}
1250
1251template <class _CharT, class _Traits>
1252inline
1253basic_ifstream<_CharT, _Traits>&
1254basic_ifstream<_CharT, _Traits>::operator=(basic_ifstream&& __rhs)
1255{
1256    basic_istream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
1257    __sb_ = _VSTD::move(__rhs.__sb_);
1258    return *this;
1259}
1260
1261template <class _CharT, class _Traits>
1262inline
1263void
1264basic_ifstream<_CharT, _Traits>::swap(basic_ifstream& __rhs)
1265{
1266    basic_istream<char_type, traits_type>::swap(__rhs);
1267    __sb_.swap(__rhs.__sb_);
1268}
1269
1270template <class _CharT, class _Traits>
1271inline _LIBCPP_INLINE_VISIBILITY
1272void
1273swap(basic_ifstream<_CharT, _Traits>& __x, basic_ifstream<_CharT, _Traits>& __y)
1274{
1275    __x.swap(__y);
1276}
1277
1278template <class _CharT, class _Traits>
1279inline
1280basic_filebuf<_CharT, _Traits>*
1281basic_ifstream<_CharT, _Traits>::rdbuf() const
1282{
1283    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
1284}
1285
1286template <class _CharT, class _Traits>
1287inline
1288bool
1289basic_ifstream<_CharT, _Traits>::is_open() const
1290{
1291    return __sb_.is_open();
1292}
1293
1294template <class _CharT, class _Traits>
1295void
1296basic_ifstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
1297{
1298    if (__sb_.open(__s, __mode | ios_base::in))
1299        this->clear();
1300    else
1301        this->setstate(ios_base::failbit);
1302}
1303
1304#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1305template <class _CharT, class _Traits>
1306void
1307basic_ifstream<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode)
1308{
1309    if (__sb_.open(__s, __mode | ios_base::in))
1310        this->clear();
1311    else
1312        this->setstate(ios_base::failbit);
1313}
1314#endif
1315
1316template <class _CharT, class _Traits>
1317void
1318basic_ifstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
1319{
1320    if (__sb_.open(__s, __mode | ios_base::in))
1321        this->clear();
1322    else
1323        this->setstate(ios_base::failbit);
1324}
1325
1326template <class _CharT, class _Traits>
1327inline
1328void basic_ifstream<_CharT, _Traits>::__open(int __fd,
1329                                             ios_base::openmode __mode) {
1330  if (__sb_.__open(__fd, __mode | ios_base::in))
1331    this->clear();
1332  else
1333    this->setstate(ios_base::failbit);
1334}
1335
1336template <class _CharT, class _Traits>
1337inline
1338void
1339basic_ifstream<_CharT, _Traits>::close()
1340{
1341    if (__sb_.close() == 0)
1342        this->setstate(ios_base::failbit);
1343}
1344
1345// basic_ofstream
1346
1347template <class _CharT, class _Traits>
1348class _LIBCPP_TEMPLATE_VIS basic_ofstream
1349    : public basic_ostream<_CharT, _Traits>
1350{
1351public:
1352    typedef _CharT                         char_type;
1353    typedef _Traits                        traits_type;
1354    typedef typename traits_type::int_type int_type;
1355    typedef typename traits_type::pos_type pos_type;
1356    typedef typename traits_type::off_type off_type;
1357
1358    _LIBCPP_INLINE_VISIBILITY
1359    basic_ofstream();
1360    _LIBCPP_INLINE_VISIBILITY
1361    explicit basic_ofstream(const char* __s, ios_base::openmode __mode = ios_base::out);
1362#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1363    _LIBCPP_INLINE_VISIBILITY
1364    explicit basic_ofstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::out);
1365#endif
1366    _LIBCPP_INLINE_VISIBILITY
1367    explicit basic_ofstream(const string& __s, ios_base::openmode __mode = ios_base::out);
1368
1369#if _LIBCPP_STD_VER >= 17
1370    _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY _LIBCPP_INLINE_VISIBILITY
1371    explicit basic_ofstream(const filesystem::path& __p, ios_base::openmode __mode = ios_base::out)
1372      : basic_ofstream(__p.c_str(), __mode) {}
1373#endif // _LIBCPP_STD_VER >= 17
1374
1375    _LIBCPP_INLINE_VISIBILITY
1376    basic_ofstream(basic_ofstream&& __rhs);
1377    _LIBCPP_INLINE_VISIBILITY
1378    basic_ofstream& operator=(basic_ofstream&& __rhs);
1379    _LIBCPP_INLINE_VISIBILITY
1380    void swap(basic_ofstream& __rhs);
1381
1382    _LIBCPP_INLINE_VISIBILITY
1383    basic_filebuf<char_type, traits_type>* rdbuf() const;
1384    _LIBCPP_INLINE_VISIBILITY
1385    bool is_open() const;
1386    void open(const char* __s, ios_base::openmode __mode = ios_base::out);
1387#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1388    void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::out);
1389#endif
1390    void open(const string& __s, ios_base::openmode __mode = ios_base::out);
1391
1392#if _LIBCPP_STD_VER >= 17
1393    _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY _LIBCPP_INLINE_VISIBILITY
1394    void open(const filesystem::path& __p, ios_base::openmode __mode = ios_base::out)
1395    { return open(__p.c_str(), __mode); }
1396#endif // _LIBCPP_STD_VER >= 17
1397
1398    _LIBCPP_INLINE_VISIBILITY
1399    void __open(int __fd, ios_base::openmode __mode);
1400    _LIBCPP_INLINE_VISIBILITY
1401    void close();
1402
1403private:
1404    basic_filebuf<char_type, traits_type> __sb_;
1405};
1406
1407template <class _CharT, class _Traits>
1408inline
1409basic_ofstream<_CharT, _Traits>::basic_ofstream()
1410    : basic_ostream<char_type, traits_type>(&__sb_)
1411{
1412}
1413
1414template <class _CharT, class _Traits>
1415inline
1416basic_ofstream<_CharT, _Traits>::basic_ofstream(const char* __s, ios_base::openmode __mode)
1417    : basic_ostream<char_type, traits_type>(&__sb_)
1418{
1419    if (__sb_.open(__s, __mode | ios_base::out) == nullptr)
1420        this->setstate(ios_base::failbit);
1421}
1422
1423#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1424template <class _CharT, class _Traits>
1425inline
1426basic_ofstream<_CharT, _Traits>::basic_ofstream(const wchar_t* __s, ios_base::openmode __mode)
1427    : basic_ostream<char_type, traits_type>(&__sb_)
1428{
1429    if (__sb_.open(__s, __mode | ios_base::out) == nullptr)
1430        this->setstate(ios_base::failbit);
1431}
1432#endif
1433
1434template <class _CharT, class _Traits>
1435inline
1436basic_ofstream<_CharT, _Traits>::basic_ofstream(const string& __s, ios_base::openmode __mode)
1437    : basic_ostream<char_type, traits_type>(&__sb_)
1438{
1439    if (__sb_.open(__s, __mode | ios_base::out) == nullptr)
1440        this->setstate(ios_base::failbit);
1441}
1442
1443template <class _CharT, class _Traits>
1444inline
1445basic_ofstream<_CharT, _Traits>::basic_ofstream(basic_ofstream&& __rhs)
1446    : basic_ostream<char_type, traits_type>(_VSTD::move(__rhs)),
1447      __sb_(_VSTD::move(__rhs.__sb_))
1448{
1449    this->set_rdbuf(&__sb_);
1450}
1451
1452template <class _CharT, class _Traits>
1453inline
1454basic_ofstream<_CharT, _Traits>&
1455basic_ofstream<_CharT, _Traits>::operator=(basic_ofstream&& __rhs)
1456{
1457    basic_ostream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
1458    __sb_ = _VSTD::move(__rhs.__sb_);
1459    return *this;
1460}
1461
1462template <class _CharT, class _Traits>
1463inline
1464void
1465basic_ofstream<_CharT, _Traits>::swap(basic_ofstream& __rhs)
1466{
1467    basic_ostream<char_type, traits_type>::swap(__rhs);
1468    __sb_.swap(__rhs.__sb_);
1469}
1470
1471template <class _CharT, class _Traits>
1472inline _LIBCPP_INLINE_VISIBILITY
1473void
1474swap(basic_ofstream<_CharT, _Traits>& __x, basic_ofstream<_CharT, _Traits>& __y)
1475{
1476    __x.swap(__y);
1477}
1478
1479template <class _CharT, class _Traits>
1480inline
1481basic_filebuf<_CharT, _Traits>*
1482basic_ofstream<_CharT, _Traits>::rdbuf() const
1483{
1484    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
1485}
1486
1487template <class _CharT, class _Traits>
1488inline
1489bool
1490basic_ofstream<_CharT, _Traits>::is_open() const
1491{
1492    return __sb_.is_open();
1493}
1494
1495template <class _CharT, class _Traits>
1496void
1497basic_ofstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
1498{
1499    if (__sb_.open(__s, __mode | ios_base::out))
1500        this->clear();
1501    else
1502        this->setstate(ios_base::failbit);
1503}
1504
1505#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1506template <class _CharT, class _Traits>
1507void
1508basic_ofstream<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode)
1509{
1510    if (__sb_.open(__s, __mode | ios_base::out))
1511        this->clear();
1512    else
1513        this->setstate(ios_base::failbit);
1514}
1515#endif
1516
1517template <class _CharT, class _Traits>
1518void
1519basic_ofstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
1520{
1521    if (__sb_.open(__s, __mode | ios_base::out))
1522        this->clear();
1523    else
1524        this->setstate(ios_base::failbit);
1525}
1526
1527template <class _CharT, class _Traits>
1528inline
1529void basic_ofstream<_CharT, _Traits>::__open(int __fd,
1530                                             ios_base::openmode __mode) {
1531  if (__sb_.__open(__fd, __mode | ios_base::out))
1532    this->clear();
1533  else
1534    this->setstate(ios_base::failbit);
1535}
1536
1537template <class _CharT, class _Traits>
1538inline
1539void
1540basic_ofstream<_CharT, _Traits>::close()
1541{
1542    if (__sb_.close() == nullptr)
1543        this->setstate(ios_base::failbit);
1544}
1545
1546// basic_fstream
1547
1548template <class _CharT, class _Traits>
1549class _LIBCPP_TEMPLATE_VIS basic_fstream
1550    : public basic_iostream<_CharT, _Traits>
1551{
1552public:
1553    typedef _CharT                         char_type;
1554    typedef _Traits                        traits_type;
1555    typedef typename traits_type::int_type int_type;
1556    typedef typename traits_type::pos_type pos_type;
1557    typedef typename traits_type::off_type off_type;
1558
1559    _LIBCPP_INLINE_VISIBILITY
1560    basic_fstream();
1561    _LIBCPP_INLINE_VISIBILITY
1562    explicit basic_fstream(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
1563#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1564    _LIBCPP_INLINE_VISIBILITY
1565    explicit basic_fstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
1566#endif
1567    _LIBCPP_INLINE_VISIBILITY
1568    explicit basic_fstream(const string& __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
1569
1570#if _LIBCPP_STD_VER >= 17
1571    _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY _LIBCPP_INLINE_VISIBILITY
1572    explicit basic_fstream(const filesystem::path& __p, ios_base::openmode __mode = ios_base::in | ios_base::out)
1573      : basic_fstream(__p.c_str(), __mode) {}
1574#endif // _LIBCPP_STD_VER >= 17
1575
1576    _LIBCPP_INLINE_VISIBILITY
1577    basic_fstream(basic_fstream&& __rhs);
1578
1579    _LIBCPP_INLINE_VISIBILITY
1580    basic_fstream& operator=(basic_fstream&& __rhs);
1581
1582    _LIBCPP_INLINE_VISIBILITY
1583    void swap(basic_fstream& __rhs);
1584
1585    _LIBCPP_INLINE_VISIBILITY
1586    basic_filebuf<char_type, traits_type>* rdbuf() const;
1587    _LIBCPP_INLINE_VISIBILITY
1588    bool is_open() const;
1589    _LIBCPP_HIDE_FROM_ABI void open(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
1590#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1591    void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
1592#endif
1593    _LIBCPP_HIDE_FROM_ABI void open(const string& __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
1594
1595#if _LIBCPP_STD_VER >= 17
1596    _LIBCPP_AVAILABILITY_FILESYSTEM_LIBRARY _LIBCPP_INLINE_VISIBILITY
1597    void open(const filesystem::path& __p, ios_base::openmode __mode = ios_base::in|ios_base::out)
1598    { return open(__p.c_str(), __mode); }
1599#endif // _LIBCPP_STD_VER >= 17
1600
1601    _LIBCPP_INLINE_VISIBILITY
1602    void close();
1603
1604private:
1605    basic_filebuf<char_type, traits_type> __sb_;
1606};
1607
1608template <class _CharT, class _Traits>
1609inline
1610basic_fstream<_CharT, _Traits>::basic_fstream()
1611    : basic_iostream<char_type, traits_type>(&__sb_)
1612{
1613}
1614
1615template <class _CharT, class _Traits>
1616inline
1617basic_fstream<_CharT, _Traits>::basic_fstream(const char* __s, ios_base::openmode __mode)
1618    : basic_iostream<char_type, traits_type>(&__sb_)
1619{
1620    if (__sb_.open(__s, __mode) == nullptr)
1621        this->setstate(ios_base::failbit);
1622}
1623
1624#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1625template <class _CharT, class _Traits>
1626inline
1627basic_fstream<_CharT, _Traits>::basic_fstream(const wchar_t* __s, ios_base::openmode __mode)
1628    : basic_iostream<char_type, traits_type>(&__sb_)
1629{
1630    if (__sb_.open(__s, __mode) == nullptr)
1631        this->setstate(ios_base::failbit);
1632}
1633#endif
1634
1635template <class _CharT, class _Traits>
1636inline
1637basic_fstream<_CharT, _Traits>::basic_fstream(const string& __s, ios_base::openmode __mode)
1638    : basic_iostream<char_type, traits_type>(&__sb_)
1639{
1640    if (__sb_.open(__s, __mode) == nullptr)
1641        this->setstate(ios_base::failbit);
1642}
1643
1644template <class _CharT, class _Traits>
1645inline
1646basic_fstream<_CharT, _Traits>::basic_fstream(basic_fstream&& __rhs)
1647    : basic_iostream<char_type, traits_type>(_VSTD::move(__rhs)),
1648      __sb_(_VSTD::move(__rhs.__sb_))
1649{
1650    this->set_rdbuf(&__sb_);
1651}
1652
1653template <class _CharT, class _Traits>
1654inline
1655basic_fstream<_CharT, _Traits>&
1656basic_fstream<_CharT, _Traits>::operator=(basic_fstream&& __rhs)
1657{
1658    basic_iostream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
1659    __sb_ = _VSTD::move(__rhs.__sb_);
1660    return *this;
1661}
1662
1663template <class _CharT, class _Traits>
1664inline
1665void
1666basic_fstream<_CharT, _Traits>::swap(basic_fstream& __rhs)
1667{
1668    basic_iostream<char_type, traits_type>::swap(__rhs);
1669    __sb_.swap(__rhs.__sb_);
1670}
1671
1672template <class _CharT, class _Traits>
1673inline _LIBCPP_INLINE_VISIBILITY
1674void
1675swap(basic_fstream<_CharT, _Traits>& __x, basic_fstream<_CharT, _Traits>& __y)
1676{
1677    __x.swap(__y);
1678}
1679
1680template <class _CharT, class _Traits>
1681inline
1682basic_filebuf<_CharT, _Traits>*
1683basic_fstream<_CharT, _Traits>::rdbuf() const
1684{
1685    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
1686}
1687
1688template <class _CharT, class _Traits>
1689inline
1690bool
1691basic_fstream<_CharT, _Traits>::is_open() const
1692{
1693    return __sb_.is_open();
1694}
1695
1696template <class _CharT, class _Traits>
1697void
1698basic_fstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
1699{
1700    if (__sb_.open(__s, __mode))
1701        this->clear();
1702    else
1703        this->setstate(ios_base::failbit);
1704}
1705
1706#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
1707template <class _CharT, class _Traits>
1708void
1709basic_fstream<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode)
1710{
1711    if (__sb_.open(__s, __mode))
1712        this->clear();
1713    else
1714        this->setstate(ios_base::failbit);
1715}
1716#endif
1717
1718template <class _CharT, class _Traits>
1719void
1720basic_fstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
1721{
1722    if (__sb_.open(__s, __mode))
1723        this->clear();
1724    else
1725        this->setstate(ios_base::failbit);
1726}
1727
1728template <class _CharT, class _Traits>
1729inline
1730void
1731basic_fstream<_CharT, _Traits>::close()
1732{
1733    if (__sb_.close() == nullptr)
1734        this->setstate(ios_base::failbit);
1735}
1736
1737#if defined(_LIBCPP_ABI_ENABLE_ADDITIONAL_IOSTREAM_EXPLICIT_INSTANTIATIONS_1)
1738extern template class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_ifstream<char>;
1739extern template class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_ofstream<char>;
1740extern template class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_filebuf<char>;
1741#endif
1742
1743_LIBCPP_END_NAMESPACE_STD
1744
1745#endif // _LIBCPP_HAS_NO_FILESYSTEM
1746
1747_LIBCPP_POP_MACROS
1748
1749#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
1750#  include <atomic>
1751#  include <concepts>
1752#  include <cstdlib>
1753#  include <iosfwd>
1754#  include <limits>
1755#  include <new>
1756#  include <stdexcept>
1757#  include <type_traits>
1758#endif
1759
1760#endif // _LIBCPP_FSTREAM
1761