1// -*- C++ -*-
2//===------------------------- fstream ------------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_FSTREAM
12#define _LIBCPP_FSTREAM
13
14/*
15    fstream synopsis
16
17template <class charT, class traits = char_traits<charT> >
18class basic_filebuf
19    : public basic_streambuf<charT, traits>
20{
21public:
22    typedef charT                          char_type;
23    typedef traits                         traits_type;
24    typedef typename traits_type::int_type int_type;
25    typedef typename traits_type::pos_type pos_type;
26    typedef typename traits_type::off_type off_type;
27
28    // 27.9.1.2 Constructors/destructor:
29    basic_filebuf();
30    basic_filebuf(basic_filebuf&& rhs);
31    virtual ~basic_filebuf();
32
33    // 27.9.1.3 Assign/swap:
34    basic_filebuf& operator=(basic_filebuf&& rhs);
35    void swap(basic_filebuf& rhs);
36
37    // 27.9.1.4 Members:
38    bool is_open() const;
39    basic_filebuf* open(const char* s, ios_base::openmode mode);
40    basic_filebuf* open(const string& s, ios_base::openmode mode);
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    basic_ifstream(basic_ifstream&& rhs);
81
82    basic_ifstream& operator=(basic_ifstream&& rhs);
83    void swap(basic_ifstream& rhs);
84
85    basic_filebuf<char_type, traits_type>* rdbuf() const;
86    bool is_open() const;
87    void open(const char* s, ios_base::openmode mode = ios_base::in);
88    void open(const string& s, ios_base::openmode mode = ios_base::in);
89    void close();
90};
91
92template <class charT, class traits>
93  void
94  swap(basic_ifstream<charT, traits>& x, basic_ifstream<charT, traits>& y);
95
96typedef basic_ifstream<char>    ifstream;
97typedef basic_ifstream<wchar_t> wifstream;
98
99template <class charT, class traits = char_traits<charT> >
100class basic_ofstream
101    : public basic_ostream<charT,traits>
102{
103public:
104    typedef charT                          char_type;
105    typedef traits                         traits_type;
106    typedef typename traits_type::int_type int_type;
107    typedef typename traits_type::pos_type pos_type;
108    typedef typename traits_type::off_type off_type;
109
110    basic_ofstream();
111    explicit basic_ofstream(const char* s, ios_base::openmode mode = ios_base::out);
112    explicit basic_ofstream(const string& s, ios_base::openmode mode = ios_base::out);
113    basic_ofstream(basic_ofstream&& rhs);
114
115    basic_ofstream& operator=(basic_ofstream&& rhs);
116    void swap(basic_ofstream& rhs);
117
118    basic_filebuf<char_type, traits_type>* rdbuf() const;
119    bool is_open() const;
120    void open(const char* s, ios_base::openmode mode = ios_base::out);
121    void open(const string& s, ios_base::openmode mode = ios_base::out);
122    void close();
123};
124
125template <class charT, class traits>
126  void
127  swap(basic_ofstream<charT, traits>& x, basic_ofstream<charT, traits>& y);
128
129typedef basic_ofstream<char>    ofstream;
130typedef basic_ofstream<wchar_t> wofstream;
131
132template <class charT, class traits=char_traits<charT> >
133class basic_fstream
134    : public basic_iostream<charT,traits>
135{
136public:
137    typedef charT                          char_type;
138    typedef traits                         traits_type;
139    typedef typename traits_type::int_type int_type;
140    typedef typename traits_type::pos_type pos_type;
141    typedef typename traits_type::off_type off_type;
142
143    basic_fstream();
144    explicit basic_fstream(const char* s, ios_base::openmode mode = ios_base::in|ios_base::out);
145    explicit basic_fstream(const string& s, ios_base::openmode mode = ios_base::in|ios_base::out);
146    basic_fstream(basic_fstream&& rhs);
147
148    basic_fstream& operator=(basic_fstream&& rhs);
149    void swap(basic_fstream& rhs);
150
151    basic_filebuf<char_type, traits_type>* rdbuf() const;
152    bool is_open() const;
153    void open(const char* s, ios_base::openmode mode = ios_base::in|ios_base::out);
154    void open(const string& s, ios_base::openmode mode = ios_base::in|ios_base::out);
155    void close();
156};
157
158template <class charT, class traits>
159  void swap(basic_fstream<charT, traits>& x, basic_fstream<charT, traits>& y);
160
161typedef basic_fstream<char>    fstream;
162typedef basic_fstream<wchar_t> wfstream;
163
164}  // std
165
166*/
167
168#include <__config>
169#include <ostream>
170#include <istream>
171#include <__locale>
172#include <cstdio>
173
174#include <__undef_min_max>
175
176#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
177#pragma GCC system_header
178#endif
179
180_LIBCPP_BEGIN_NAMESPACE_STD
181
182template <class _CharT, class _Traits>
183class _LIBCPP_TYPE_VIS_ONLY basic_filebuf
184    : public basic_streambuf<_CharT, _Traits>
185{
186public:
187    typedef _CharT                           char_type;
188    typedef _Traits                          traits_type;
189    typedef typename traits_type::int_type   int_type;
190    typedef typename traits_type::pos_type   pos_type;
191    typedef typename traits_type::off_type   off_type;
192    typedef typename traits_type::state_type state_type;
193
194    // 27.9.1.2 Constructors/destructor:
195    basic_filebuf();
196#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
197    basic_filebuf(basic_filebuf&& __rhs);
198#endif
199    virtual ~basic_filebuf();
200
201    // 27.9.1.3 Assign/swap:
202#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
203    basic_filebuf& operator=(basic_filebuf&& __rhs);
204#endif
205    void swap(basic_filebuf& __rhs);
206
207    // 27.9.1.4 Members:
208    bool is_open() const;
209#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
210    basic_filebuf* open(const char* __s, ios_base::openmode __mode);
211    basic_filebuf* open(const string& __s, ios_base::openmode __mode);
212#endif
213    basic_filebuf* close();
214
215protected:
216    // 27.9.1.5 Overridden virtual functions:
217    virtual int_type underflow();
218    virtual int_type pbackfail(int_type __c = traits_type::eof());
219    virtual int_type overflow (int_type __c = traits_type::eof());
220    virtual basic_streambuf<char_type, traits_type>* setbuf(char_type* __s, streamsize __n);
221    virtual pos_type seekoff(off_type __off, ios_base::seekdir __way,
222                             ios_base::openmode __wch = ios_base::in | ios_base::out);
223    virtual pos_type seekpos(pos_type __sp,
224                             ios_base::openmode __wch = ios_base::in | ios_base::out);
225    virtual int sync();
226    virtual void imbue(const locale& __loc);
227
228private:
229    char*       __extbuf_;
230    const char* __extbufnext_;
231    const char* __extbufend_;
232    char __extbuf_min_[8];
233    size_t __ebs_;
234    char_type* __intbuf_;
235    size_t __ibs_;
236    FILE* __file_;
237    const codecvt<char_type, char, state_type>* __cv_;
238    state_type __st_;
239    state_type __st_last_;
240    ios_base::openmode __om_;
241    ios_base::openmode __cm_;
242    bool __owns_eb_;
243    bool __owns_ib_;
244    bool __always_noconv_;
245
246    bool __read_mode();
247    void __write_mode();
248};
249
250template <class _CharT, class _Traits>
251basic_filebuf<_CharT, _Traits>::basic_filebuf()
252    : __extbuf_(0),
253      __extbufnext_(0),
254      __extbufend_(0),
255      __ebs_(0),
256      __intbuf_(0),
257      __ibs_(0),
258      __file_(0),
259      __cv_(nullptr),
260      __st_(),
261      __st_last_(),
262      __om_(0),
263      __cm_(0),
264      __owns_eb_(false),
265      __owns_ib_(false),
266      __always_noconv_(false)
267{
268    if (has_facet<codecvt<char_type, char, state_type> >(this->getloc()))
269    {
270        __cv_ = &use_facet<codecvt<char_type, char, state_type> >(this->getloc());
271        __always_noconv_ = __cv_->always_noconv();
272    }
273    setbuf(0, 4096);
274}
275
276#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
277
278template <class _CharT, class _Traits>
279basic_filebuf<_CharT, _Traits>::basic_filebuf(basic_filebuf&& __rhs)
280    : basic_streambuf<_CharT, _Traits>(__rhs)
281{
282    if (__rhs.__extbuf_ == __rhs.__extbuf_min_)
283    {
284        __extbuf_ = __extbuf_min_;
285        __extbufnext_ = __extbuf_ + (__rhs.__extbufnext_ - __rhs.__extbuf_);
286        __extbufend_ = __extbuf_ + (__rhs.__extbufend_ - __rhs.__extbuf_);
287    }
288    else
289    {
290        __extbuf_ = __rhs.__extbuf_;
291        __extbufnext_ = __rhs.__extbufnext_;
292        __extbufend_ = __rhs.__extbufend_;
293    }
294    __ebs_ = __rhs.__ebs_;
295    __intbuf_ = __rhs.__intbuf_;
296    __ibs_ = __rhs.__ibs_;
297    __file_ = __rhs.__file_;
298    __cv_ = __rhs.__cv_;
299    __st_ = __rhs.__st_;
300    __st_last_ = __rhs.__st_last_;
301    __om_ = __rhs.__om_;
302    __cm_ = __rhs.__cm_;
303    __owns_eb_ = __rhs.__owns_eb_;
304    __owns_ib_ = __rhs.__owns_ib_;
305    __always_noconv_ = __rhs.__always_noconv_;
306    if (__rhs.pbase())
307    {
308        if (__rhs.pbase() == __rhs.__intbuf_)
309            this->setp(__intbuf_, __intbuf_ + (__rhs. epptr() - __rhs.pbase()));
310        else
311            this->setp((char_type*)__extbuf_,
312                       (char_type*)__extbuf_ + (__rhs. epptr() - __rhs.pbase()));
313        this->pbump(__rhs. pptr() - __rhs.pbase());
314    }
315    else if (__rhs.eback())
316    {
317        if (__rhs.eback() == __rhs.__intbuf_)
318            this->setg(__intbuf_, __intbuf_ + (__rhs.gptr() - __rhs.eback()),
319                                  __intbuf_ + (__rhs.egptr() - __rhs.eback()));
320        else
321            this->setg((char_type*)__extbuf_,
322                       (char_type*)__extbuf_ + (__rhs.gptr() - __rhs.eback()),
323                       (char_type*)__extbuf_ + (__rhs.egptr() - __rhs.eback()));
324    }
325    __rhs.__extbuf_ = 0;
326    __rhs.__extbufnext_ = 0;
327    __rhs.__extbufend_ = 0;
328    __rhs.__ebs_ = 0;
329    __rhs.__intbuf_ = 0;
330    __rhs.__ibs_ = 0;
331    __rhs.__file_ = 0;
332    __rhs.__st_ = state_type();
333    __rhs.__st_last_ = state_type();
334    __rhs.__om_ = 0;
335    __rhs.__cm_ = 0;
336    __rhs.__owns_eb_ = false;
337    __rhs.__owns_ib_ = false;
338    __rhs.setg(0, 0, 0);
339    __rhs.setp(0, 0);
340}
341
342template <class _CharT, class _Traits>
343inline _LIBCPP_INLINE_VISIBILITY
344basic_filebuf<_CharT, _Traits>&
345basic_filebuf<_CharT, _Traits>::operator=(basic_filebuf&& __rhs)
346{
347    close();
348    swap(__rhs);
349    return *this;
350}
351
352#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
353
354template <class _CharT, class _Traits>
355basic_filebuf<_CharT, _Traits>::~basic_filebuf()
356{
357#ifndef _LIBCPP_NO_EXCEPTIONS
358    try
359    {
360#endif  // _LIBCPP_NO_EXCEPTIONS
361        close();
362#ifndef _LIBCPP_NO_EXCEPTIONS
363    }
364    catch (...)
365    {
366    }
367#endif  // _LIBCPP_NO_EXCEPTIONS
368    if (__owns_eb_)
369        delete [] __extbuf_;
370    if (__owns_ib_)
371        delete [] __intbuf_;
372}
373
374template <class _CharT, class _Traits>
375void
376basic_filebuf<_CharT, _Traits>::swap(basic_filebuf& __rhs)
377{
378    basic_streambuf<char_type, traits_type>::swap(__rhs);
379    if (__extbuf_ != __extbuf_min_ && __rhs.__extbuf_ != __rhs.__extbuf_min_)
380    {
381        _VSTD::swap(__extbuf_, __rhs.__extbuf_);
382        _VSTD::swap(__extbufnext_, __rhs.__extbufnext_);
383        _VSTD::swap(__extbufend_, __rhs.__extbufend_);
384    }
385    else
386    {
387        ptrdiff_t __ln = __extbufnext_ - __extbuf_;
388        ptrdiff_t __le = __extbufend_ - __extbuf_;
389        ptrdiff_t __rn = __rhs.__extbufnext_ - __rhs.__extbuf_;
390        ptrdiff_t __re = __rhs.__extbufend_ - __rhs.__extbuf_;
391        if (__extbuf_ == __extbuf_min_ && __rhs.__extbuf_ != __rhs.__extbuf_min_)
392        {
393            __extbuf_ = __rhs.__extbuf_;
394            __rhs.__extbuf_ = __rhs.__extbuf_min_;
395        }
396        else if (__extbuf_ != __extbuf_min_ && __rhs.__extbuf_ == __rhs.__extbuf_min_)
397        {
398            __rhs.__extbuf_ = __extbuf_;
399            __extbuf_ = __extbuf_min_;
400        }
401        __extbufnext_ = __extbuf_ + __rn;
402        __extbufend_ = __extbuf_ + __re;
403        __rhs.__extbufnext_ = __rhs.__extbuf_ + __ln;
404        __rhs.__extbufend_ = __rhs.__extbuf_ + __le;
405    }
406    _VSTD::swap(__ebs_, __rhs.__ebs_);
407    _VSTD::swap(__intbuf_, __rhs.__intbuf_);
408    _VSTD::swap(__ibs_, __rhs.__ibs_);
409    _VSTD::swap(__file_, __rhs.__file_);
410    _VSTD::swap(__cv_, __rhs.__cv_);
411    _VSTD::swap(__st_, __rhs.__st_);
412    _VSTD::swap(__st_last_, __rhs.__st_last_);
413    _VSTD::swap(__om_, __rhs.__om_);
414    _VSTD::swap(__cm_, __rhs.__cm_);
415    _VSTD::swap(__owns_eb_, __rhs.__owns_eb_);
416    _VSTD::swap(__owns_ib_, __rhs.__owns_ib_);
417    _VSTD::swap(__always_noconv_, __rhs.__always_noconv_);
418    if (this->eback() == (char_type*)__rhs.__extbuf_min_)
419    {
420        ptrdiff_t __n = this->gptr() - this->eback();
421        ptrdiff_t __e = this->egptr() - this->eback();
422        this->setg((char_type*)__extbuf_min_,
423                   (char_type*)__extbuf_min_ + __n,
424                   (char_type*)__extbuf_min_ + __e);
425    }
426    else if (this->pbase() == (char_type*)__rhs.__extbuf_min_)
427    {
428        ptrdiff_t __n = this->pptr() - this->pbase();
429        ptrdiff_t __e = this->epptr() - this->pbase();
430        this->setp((char_type*)__extbuf_min_,
431                   (char_type*)__extbuf_min_ + __e);
432        this->pbump(__n);
433    }
434    if (__rhs.eback() == (char_type*)__extbuf_min_)
435    {
436        ptrdiff_t __n = __rhs.gptr() - __rhs.eback();
437        ptrdiff_t __e = __rhs.egptr() - __rhs.eback();
438        __rhs.setg((char_type*)__rhs.__extbuf_min_,
439                   (char_type*)__rhs.__extbuf_min_ + __n,
440                   (char_type*)__rhs.__extbuf_min_ + __e);
441    }
442    else if (__rhs.pbase() == (char_type*)__extbuf_min_)
443    {
444        ptrdiff_t __n = __rhs.pptr() - __rhs.pbase();
445        ptrdiff_t __e = __rhs.epptr() - __rhs.pbase();
446        __rhs.setp((char_type*)__rhs.__extbuf_min_,
447                   (char_type*)__rhs.__extbuf_min_ + __e);
448        __rhs.pbump(__n);
449    }
450}
451
452template <class _CharT, class _Traits>
453inline _LIBCPP_INLINE_VISIBILITY
454void
455swap(basic_filebuf<_CharT, _Traits>& __x, basic_filebuf<_CharT, _Traits>& __y)
456{
457    __x.swap(__y);
458}
459
460template <class _CharT, class _Traits>
461inline _LIBCPP_INLINE_VISIBILITY
462bool
463basic_filebuf<_CharT, _Traits>::is_open() const
464{
465    return __file_ != 0;
466}
467
468#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
469template <class _CharT, class _Traits>
470basic_filebuf<_CharT, _Traits>*
471basic_filebuf<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
472{
473    basic_filebuf<_CharT, _Traits>* __rt = 0;
474    if (__file_ == 0)
475    {
476        __rt = this;
477        const char* __mdstr;
478        switch (__mode & ~ios_base::ate)
479        {
480        case ios_base::out:
481        case ios_base::out | ios_base::trunc:
482            __mdstr = "w";
483            break;
484        case ios_base::out | ios_base::app:
485        case ios_base::app:
486            __mdstr = "a";
487            break;
488        case ios_base::in:
489            __mdstr = "r";
490            break;
491        case ios_base::in | ios_base::out:
492            __mdstr = "r+";
493            break;
494        case ios_base::in | ios_base::out | ios_base::trunc:
495            __mdstr = "w+";
496            break;
497        case ios_base::in | ios_base::out | ios_base::app:
498        case ios_base::in | ios_base::app:
499            __mdstr = "a+";
500            break;
501        case ios_base::out | ios_base::binary:
502        case ios_base::out | ios_base::trunc | ios_base::binary:
503            __mdstr = "wb";
504            break;
505        case ios_base::out | ios_base::app | ios_base::binary:
506        case ios_base::app | ios_base::binary:
507            __mdstr = "ab";
508            break;
509        case ios_base::in | ios_base::binary:
510            __mdstr = "rb";
511            break;
512        case ios_base::in | ios_base::out | ios_base::binary:
513            __mdstr = "r+b";
514            break;
515        case ios_base::in | ios_base::out | ios_base::trunc | ios_base::binary:
516            __mdstr = "w+b";
517            break;
518        case ios_base::in | ios_base::out | ios_base::app | ios_base::binary:
519        case ios_base::in | ios_base::app | ios_base::binary:
520            __mdstr = "a+b";
521            break;
522        default:
523            __rt = 0;
524            break;
525        }
526        if (__rt)
527        {
528            __file_ = fopen(__s, __mdstr);
529            if (__file_)
530            {
531                __om_ = __mode;
532                if (__mode & ios_base::ate)
533                {
534                    if (fseek(__file_, 0, SEEK_END))
535                    {
536                        fclose(__file_);
537                        __file_ = 0;
538                        __rt = 0;
539                    }
540                }
541            }
542            else
543                __rt = 0;
544        }
545    }
546    return __rt;
547}
548
549template <class _CharT, class _Traits>
550inline _LIBCPP_INLINE_VISIBILITY
551basic_filebuf<_CharT, _Traits>*
552basic_filebuf<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
553{
554    return open(__s.c_str(), __mode);
555}
556#endif
557
558template <class _CharT, class _Traits>
559basic_filebuf<_CharT, _Traits>*
560basic_filebuf<_CharT, _Traits>::close()
561{
562    basic_filebuf<_CharT, _Traits>* __rt = 0;
563    if (__file_)
564    {
565        __rt = this;
566        unique_ptr<FILE, int(*)(FILE*)> __h(__file_, fclose);
567        if (sync())
568            __rt = 0;
569        if (fclose(__h.release()) == 0)
570            __file_ = 0;
571        else
572            __rt = 0;
573    }
574    return __rt;
575}
576
577template <class _CharT, class _Traits>
578typename basic_filebuf<_CharT, _Traits>::int_type
579basic_filebuf<_CharT, _Traits>::underflow()
580{
581    if (__file_ == 0)
582        return traits_type::eof();
583    bool __initial = __read_mode();
584    char_type __1buf;
585    if (this->gptr() == 0)
586        this->setg(&__1buf, &__1buf+1, &__1buf+1);
587    const size_t __unget_sz = __initial ? 0 : min<size_t>((this->egptr() - this->eback()) / 2, 4);
588    int_type __c = traits_type::eof();
589    if (this->gptr() == this->egptr())
590    {
591        memmove(this->eback(), this->egptr() - __unget_sz, __unget_sz * sizeof(char_type));
592        if (__always_noconv_)
593        {
594            size_t __nmemb = static_cast<size_t>(this->egptr() - this->eback() - __unget_sz);
595            __nmemb = fread(this->eback() + __unget_sz, 1, __nmemb, __file_);
596            if (__nmemb != 0)
597            {
598                this->setg(this->eback(),
599                           this->eback() + __unget_sz,
600                           this->eback() + __unget_sz + __nmemb);
601                __c = traits_type::to_int_type(*this->gptr());
602            }
603        }
604        else
605        {
606            memmove(__extbuf_, __extbufnext_, __extbufend_ - __extbufnext_);
607            __extbufnext_ = __extbuf_ + (__extbufend_ - __extbufnext_);
608            __extbufend_ = __extbuf_ + (__extbuf_ == __extbuf_min_ ? sizeof(__extbuf_min_) : __ebs_);
609            size_t __nmemb = _VSTD::min(static_cast<size_t>(__ibs_ - __unget_sz),
610                                 static_cast<size_t>(__extbufend_ - __extbufnext_));
611            codecvt_base::result __r;
612            __st_last_ = __st_;
613            size_t __nr = fread((void*)__extbufnext_, 1, __nmemb, __file_);
614            if (__nr != 0)
615            {
616#ifndef _LIBCPP_NO_EXCEPTIONS
617                if (!__cv_)
618                    throw bad_cast();
619#endif
620                __extbufend_ = __extbufnext_ + __nr;
621                char_type*  __inext;
622                __r = __cv_->in(__st_, __extbuf_, __extbufend_, __extbufnext_,
623                                       this->eback() + __unget_sz,
624                                       this->eback() + __ibs_, __inext);
625                if (__r == codecvt_base::noconv)
626                {
627                    this->setg((char_type*)__extbuf_, (char_type*)__extbuf_, (char_type*)__extbufend_);
628                    __c = traits_type::to_int_type(*this->gptr());
629                }
630                else if (__inext != this->eback() + __unget_sz)
631                {
632                    this->setg(this->eback(), this->eback() + __unget_sz, __inext);
633                    __c = traits_type::to_int_type(*this->gptr());
634                }
635            }
636        }
637    }
638    else
639        __c = traits_type::to_int_type(*this->gptr());
640    if (this->eback() == &__1buf)
641        this->setg(0, 0, 0);
642    return __c;
643}
644
645template <class _CharT, class _Traits>
646typename basic_filebuf<_CharT, _Traits>::int_type
647basic_filebuf<_CharT, _Traits>::pbackfail(int_type __c)
648{
649    if (__file_ && this->eback() < this->gptr())
650    {
651        if (traits_type::eq_int_type(__c, traits_type::eof()))
652        {
653            this->gbump(-1);
654            return traits_type::not_eof(__c);
655        }
656        if ((__om_ & ios_base::out) ||
657            traits_type::eq(traits_type::to_char_type(__c), this->gptr()[-1]))
658        {
659            this->gbump(-1);
660            *this->gptr() = traits_type::to_char_type(__c);
661            return __c;
662        }
663    }
664    return traits_type::eof();
665}
666
667template <class _CharT, class _Traits>
668typename basic_filebuf<_CharT, _Traits>::int_type
669basic_filebuf<_CharT, _Traits>::overflow(int_type __c)
670{
671    if (__file_ == 0)
672        return traits_type::eof();
673    __write_mode();
674    char_type __1buf;
675    char_type* __pb_save = this->pbase();
676    char_type* __epb_save = this->epptr();
677    if (!traits_type::eq_int_type(__c, traits_type::eof()))
678    {
679        if (this->pptr() == 0)
680            this->setp(&__1buf, &__1buf+1);
681        *this->pptr() = traits_type::to_char_type(__c);
682        this->pbump(1);
683    }
684    if (this->pptr() != this->pbase())
685    {
686        if (__always_noconv_)
687        {
688            size_t __nmemb = static_cast<size_t>(this->pptr() - this->pbase());
689            if (fwrite(this->pbase(), sizeof(char_type), __nmemb, __file_) != __nmemb)
690                return traits_type::eof();
691        }
692        else
693        {
694            char* __extbe = __extbuf_;
695            codecvt_base::result __r;
696            do
697            {
698#ifndef _LIBCPP_NO_EXCEPTIONS
699                if (!__cv_)
700                    throw bad_cast();
701#endif
702                const char_type* __e;
703                __r = __cv_->out(__st_, this->pbase(), this->pptr(), __e,
704                                        __extbuf_, __extbuf_ + __ebs_, __extbe);
705                if (__e == this->pbase())
706                    return traits_type::eof();
707                if (__r == codecvt_base::noconv)
708                {
709                    size_t __nmemb = static_cast<size_t>(this->pptr() - this->pbase());
710                    if (fwrite(this->pbase(), 1, __nmemb, __file_) != __nmemb)
711                        return traits_type::eof();
712                }
713                else if (__r == codecvt_base::ok || __r == codecvt_base::partial)
714                {
715                    size_t __nmemb = static_cast<size_t>(__extbe - __extbuf_);
716                    if (fwrite(__extbuf_, 1, __nmemb, __file_) != __nmemb)
717                        return traits_type::eof();
718                    if (__r == codecvt_base::partial)
719                    {
720                        this->setp((char_type*)__e, this->pptr());
721                        this->pbump(this->epptr() - this->pbase());
722                    }
723                }
724                else
725                    return traits_type::eof();
726            } while (__r == codecvt_base::partial);
727        }
728        this->setp(__pb_save, __epb_save);
729    }
730    return traits_type::not_eof(__c);
731}
732
733template <class _CharT, class _Traits>
734basic_streambuf<_CharT, _Traits>*
735basic_filebuf<_CharT, _Traits>::setbuf(char_type* __s, streamsize __n)
736{
737    this->setg(0, 0, 0);
738    this->setp(0, 0);
739    if (__owns_eb_)
740        delete [] __extbuf_;
741    if (__owns_ib_)
742        delete [] __intbuf_;
743    __ebs_ = __n;
744    if (__ebs_ > sizeof(__extbuf_min_))
745    {
746        if (__always_noconv_ && __s)
747        {
748            __extbuf_ = (char*)__s;
749            __owns_eb_ = false;
750        }
751        else
752        {
753            __extbuf_ = new char[__ebs_];
754            __owns_eb_ = true;
755        }
756    }
757    else
758    {
759        __extbuf_ = __extbuf_min_;
760        __ebs_ = sizeof(__extbuf_min_);
761        __owns_eb_ = false;
762    }
763    if (!__always_noconv_)
764    {
765        __ibs_ = max<streamsize>(__n, sizeof(__extbuf_min_));
766        if (__s && __ibs_ >= sizeof(__extbuf_min_))
767        {
768            __intbuf_ = __s;
769            __owns_ib_ = false;
770        }
771        else
772        {
773            __intbuf_ = new char_type[__ibs_];
774            __owns_ib_ = true;
775        }
776    }
777    else
778    {
779        __ibs_ = 0;
780        __intbuf_ = 0;
781        __owns_ib_ = false;
782    }
783    return this;
784}
785
786template <class _CharT, class _Traits>
787typename basic_filebuf<_CharT, _Traits>::pos_type
788basic_filebuf<_CharT, _Traits>::seekoff(off_type __off, ios_base::seekdir __way,
789                                        ios_base::openmode)
790{
791#ifndef _LIBCPP_NO_EXCEPTIONS
792    if (!__cv_)
793        throw bad_cast();
794#endif
795    int __width = __cv_->encoding();
796    if (__file_ == 0 || (__width <= 0 && __off != 0) || sync())
797        return pos_type(off_type(-1));
798    // __width > 0 || __off == 0
799    int __whence;
800    switch (__way)
801    {
802    case ios_base::beg:
803        __whence = SEEK_SET;
804        break;
805    case ios_base::cur:
806        __whence = SEEK_CUR;
807        break;
808    case ios_base::end:
809        __whence = SEEK_END;
810        break;
811    default:
812        return pos_type(off_type(-1));
813    }
814#if defined(_WIN32) || defined(_NEWLIB_VERSION)
815    if (fseek(__file_, __width > 0 ? __width * __off : 0, __whence))
816        return pos_type(off_type(-1));
817    pos_type __r = ftell(__file_);
818#else
819    if (fseeko(__file_, __width > 0 ? __width * __off : 0, __whence))
820        return pos_type(off_type(-1));
821    pos_type __r = ftello(__file_);
822#endif
823    __r.state(__st_);
824    return __r;
825}
826
827template <class _CharT, class _Traits>
828typename basic_filebuf<_CharT, _Traits>::pos_type
829basic_filebuf<_CharT, _Traits>::seekpos(pos_type __sp, ios_base::openmode)
830{
831    if (__file_ == 0 || sync())
832        return pos_type(off_type(-1));
833#if defined(_WIN32) || defined(_NEWLIB_VERSION)
834    if (fseek(__file_, __sp, SEEK_SET))
835        return pos_type(off_type(-1));
836#else
837    if (fseeko(__file_, __sp, SEEK_SET))
838        return pos_type(off_type(-1));
839#endif
840    __st_ = __sp.state();
841    return __sp;
842}
843
844template <class _CharT, class _Traits>
845int
846basic_filebuf<_CharT, _Traits>::sync()
847{
848    if (__file_ == 0)
849        return 0;
850#ifndef _LIBCPP_NO_EXCEPTIONS
851    if (!__cv_)
852        throw bad_cast();
853#endif
854    if (__cm_ & ios_base::out)
855    {
856        if (this->pptr() != this->pbase())
857            if (overflow() == traits_type::eof())
858                return -1;
859        codecvt_base::result __r;
860        do
861        {
862            char* __extbe;
863            __r = __cv_->unshift(__st_, __extbuf_, __extbuf_ + __ebs_, __extbe);
864            size_t __nmemb = static_cast<size_t>(__extbe - __extbuf_);
865            if (fwrite(__extbuf_, 1, __nmemb, __file_) != __nmemb)
866                return -1;
867        } while (__r == codecvt_base::partial);
868        if (__r == codecvt_base::error)
869            return -1;
870        if (fflush(__file_))
871            return -1;
872    }
873    else if (__cm_ & ios_base::in)
874    {
875        off_type __c;
876        state_type __state = __st_last_;
877        bool __update_st = false;
878        if (__always_noconv_)
879            __c = this->egptr() - this->gptr();
880        else
881        {
882            int __width = __cv_->encoding();
883            __c = __extbufend_ - __extbufnext_;
884            if (__width > 0)
885                __c += __width * (this->egptr() - this->gptr());
886            else
887            {
888                if (this->gptr() != this->egptr())
889                {
890                    const int __off =  __cv_->length(__state, __extbuf_,
891                                                     __extbufnext_,
892                                                     this->gptr() - this->eback());
893                    __c += __extbufnext_ - __extbuf_ - __off;
894                    __update_st = true;
895                }
896            }
897        }
898#if defined(_WIN32) || defined(_NEWLIB_VERSION)
899        if (fseek(__file_, -__c, SEEK_CUR))
900            return -1;
901#else
902        if (fseeko(__file_, -__c, SEEK_CUR))
903            return -1;
904#endif
905        if (__update_st)
906            __st_ = __state;
907        __extbufnext_ = __extbufend_ = __extbuf_;
908        this->setg(0, 0, 0);
909        __cm_ = 0;
910    }
911    return 0;
912}
913
914template <class _CharT, class _Traits>
915void
916basic_filebuf<_CharT, _Traits>::imbue(const locale& __loc)
917{
918    sync();
919    __cv_ = &use_facet<codecvt<char_type, char, state_type> >(__loc);
920    bool __old_anc = __always_noconv_;
921    __always_noconv_ = __cv_->always_noconv();
922    if (__old_anc != __always_noconv_)
923    {
924        this->setg(0, 0, 0);
925        this->setp(0, 0);
926        // invariant, char_type is char, else we couldn't get here
927        if (__always_noconv_)  // need to dump __intbuf_
928        {
929            if (__owns_eb_)
930                delete [] __extbuf_;
931            __owns_eb_ = __owns_ib_;
932            __ebs_ = __ibs_;
933            __extbuf_ = (char*)__intbuf_;
934            __ibs_ = 0;
935            __intbuf_ = 0;
936            __owns_ib_ = false;
937        }
938        else  // need to obtain an __intbuf_.
939        {     // If __extbuf_ is user-supplied, use it, else new __intbuf_
940            if (!__owns_eb_ && __extbuf_ != __extbuf_min_)
941            {
942                __ibs_ = __ebs_;
943                __intbuf_ = (char_type*)__extbuf_;
944                __owns_ib_ = false;
945                __extbuf_ = new char[__ebs_];
946                __owns_eb_ = true;
947            }
948            else
949            {
950                __ibs_ = __ebs_;
951                __intbuf_ = new char_type[__ibs_];
952                __owns_ib_ = true;
953            }
954        }
955    }
956}
957
958template <class _CharT, class _Traits>
959bool
960basic_filebuf<_CharT, _Traits>::__read_mode()
961{
962    if (!(__cm_ & ios_base::in))
963    {
964        this->setp(0, 0);
965        if (__always_noconv_)
966            this->setg((char_type*)__extbuf_,
967                       (char_type*)__extbuf_ + __ebs_,
968                       (char_type*)__extbuf_ + __ebs_);
969        else
970            this->setg(__intbuf_, __intbuf_ + __ibs_, __intbuf_ + __ibs_);
971        __cm_ = ios_base::in;
972        return true;
973    }
974    return false;
975}
976
977template <class _CharT, class _Traits>
978void
979basic_filebuf<_CharT, _Traits>::__write_mode()
980{
981    if (!(__cm_ & ios_base::out))
982    {
983        this->setg(0, 0, 0);
984        if (__ebs_ > sizeof(__extbuf_min_))
985        {
986            if (__always_noconv_)
987                this->setp((char_type*)__extbuf_,
988                           (char_type*)__extbuf_ + (__ebs_ - 1));
989            else
990                this->setp(__intbuf_, __intbuf_ + (__ibs_ - 1));
991        }
992        else
993            this->setp(0, 0);
994        __cm_ = ios_base::out;
995    }
996}
997
998// basic_ifstream
999
1000template <class _CharT, class _Traits>
1001class _LIBCPP_TYPE_VIS_ONLY basic_ifstream
1002    : public basic_istream<_CharT, _Traits>
1003{
1004public:
1005    typedef _CharT                         char_type;
1006    typedef _Traits                        traits_type;
1007    typedef typename traits_type::int_type int_type;
1008    typedef typename traits_type::pos_type pos_type;
1009    typedef typename traits_type::off_type off_type;
1010
1011    basic_ifstream();
1012#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
1013    explicit basic_ifstream(const char* __s, ios_base::openmode __mode = ios_base::in);
1014    explicit basic_ifstream(const string& __s, ios_base::openmode __mode = ios_base::in);
1015#endif
1016#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1017    basic_ifstream(basic_ifstream&& __rhs);
1018#endif
1019
1020#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1021    basic_ifstream& operator=(basic_ifstream&& __rhs);
1022#endif
1023    void swap(basic_ifstream& __rhs);
1024
1025    basic_filebuf<char_type, traits_type>* rdbuf() const;
1026    bool is_open() const;
1027#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
1028    void open(const char* __s, ios_base::openmode __mode = ios_base::in);
1029    void open(const string& __s, ios_base::openmode __mode = ios_base::in);
1030#endif
1031    void close();
1032
1033private:
1034    basic_filebuf<char_type, traits_type> __sb_;
1035};
1036
1037template <class _CharT, class _Traits>
1038inline _LIBCPP_INLINE_VISIBILITY
1039basic_ifstream<_CharT, _Traits>::basic_ifstream()
1040    : basic_istream<char_type, traits_type>(&__sb_)
1041{
1042}
1043
1044#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
1045template <class _CharT, class _Traits>
1046inline _LIBCPP_INLINE_VISIBILITY
1047basic_ifstream<_CharT, _Traits>::basic_ifstream(const char* __s, ios_base::openmode __mode)
1048    : basic_istream<char_type, traits_type>(&__sb_)
1049{
1050    if (__sb_.open(__s, __mode | ios_base::in) == 0)
1051        this->setstate(ios_base::failbit);
1052}
1053
1054template <class _CharT, class _Traits>
1055inline _LIBCPP_INLINE_VISIBILITY
1056basic_ifstream<_CharT, _Traits>::basic_ifstream(const string& __s, ios_base::openmode __mode)
1057    : basic_istream<char_type, traits_type>(&__sb_)
1058{
1059    if (__sb_.open(__s, __mode | ios_base::in) == 0)
1060        this->setstate(ios_base::failbit);
1061}
1062#endif
1063
1064#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1065
1066template <class _CharT, class _Traits>
1067inline _LIBCPP_INLINE_VISIBILITY
1068basic_ifstream<_CharT, _Traits>::basic_ifstream(basic_ifstream&& __rhs)
1069    : basic_istream<char_type, traits_type>(_VSTD::move(__rhs)),
1070      __sb_(_VSTD::move(__rhs.__sb_))
1071{
1072    this->set_rdbuf(&__sb_);
1073}
1074
1075template <class _CharT, class _Traits>
1076inline _LIBCPP_INLINE_VISIBILITY
1077basic_ifstream<_CharT, _Traits>&
1078basic_ifstream<_CharT, _Traits>::operator=(basic_ifstream&& __rhs)
1079{
1080    basic_istream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
1081    __sb_ = _VSTD::move(__rhs.__sb_);
1082    return *this;
1083}
1084
1085#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
1086
1087template <class _CharT, class _Traits>
1088inline _LIBCPP_INLINE_VISIBILITY
1089void
1090basic_ifstream<_CharT, _Traits>::swap(basic_ifstream& __rhs)
1091{
1092    basic_istream<char_type, traits_type>::swap(__rhs);
1093    __sb_.swap(__rhs.__sb_);
1094}
1095
1096template <class _CharT, class _Traits>
1097inline _LIBCPP_INLINE_VISIBILITY
1098void
1099swap(basic_ifstream<_CharT, _Traits>& __x, basic_ifstream<_CharT, _Traits>& __y)
1100{
1101    __x.swap(__y);
1102}
1103
1104template <class _CharT, class _Traits>
1105inline _LIBCPP_INLINE_VISIBILITY
1106basic_filebuf<_CharT, _Traits>*
1107basic_ifstream<_CharT, _Traits>::rdbuf() const
1108{
1109    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
1110}
1111
1112template <class _CharT, class _Traits>
1113inline _LIBCPP_INLINE_VISIBILITY
1114bool
1115basic_ifstream<_CharT, _Traits>::is_open() const
1116{
1117    return __sb_.is_open();
1118}
1119
1120#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
1121template <class _CharT, class _Traits>
1122void
1123basic_ifstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
1124{
1125    if (__sb_.open(__s, __mode | ios_base::in))
1126        this->clear();
1127    else
1128        this->setstate(ios_base::failbit);
1129}
1130
1131template <class _CharT, class _Traits>
1132void
1133basic_ifstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
1134{
1135    if (__sb_.open(__s, __mode | ios_base::in))
1136        this->clear();
1137    else
1138        this->setstate(ios_base::failbit);
1139}
1140#endif
1141
1142template <class _CharT, class _Traits>
1143inline _LIBCPP_INLINE_VISIBILITY
1144void
1145basic_ifstream<_CharT, _Traits>::close()
1146{
1147    if (__sb_.close() == 0)
1148        this->setstate(ios_base::failbit);
1149}
1150
1151// basic_ofstream
1152
1153template <class _CharT, class _Traits>
1154class _LIBCPP_TYPE_VIS_ONLY basic_ofstream
1155    : public basic_ostream<_CharT, _Traits>
1156{
1157public:
1158    typedef _CharT                         char_type;
1159    typedef _Traits                        traits_type;
1160    typedef typename traits_type::int_type int_type;
1161    typedef typename traits_type::pos_type pos_type;
1162    typedef typename traits_type::off_type off_type;
1163
1164    basic_ofstream();
1165    explicit basic_ofstream(const char* __s, ios_base::openmode __mode = ios_base::out);
1166    explicit basic_ofstream(const string& __s, ios_base::openmode __mode = ios_base::out);
1167#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1168    basic_ofstream(basic_ofstream&& __rhs);
1169#endif
1170
1171#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1172    basic_ofstream& operator=(basic_ofstream&& __rhs);
1173#endif
1174    void swap(basic_ofstream& __rhs);
1175
1176    basic_filebuf<char_type, traits_type>* rdbuf() const;
1177    bool is_open() const;
1178#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
1179    void open(const char* __s, ios_base::openmode __mode = ios_base::out);
1180    void open(const string& __s, ios_base::openmode __mode = ios_base::out);
1181#endif
1182    void close();
1183
1184private:
1185    basic_filebuf<char_type, traits_type> __sb_;
1186};
1187
1188template <class _CharT, class _Traits>
1189inline _LIBCPP_INLINE_VISIBILITY
1190basic_ofstream<_CharT, _Traits>::basic_ofstream()
1191    : basic_ostream<char_type, traits_type>(&__sb_)
1192{
1193}
1194
1195#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
1196template <class _CharT, class _Traits>
1197inline _LIBCPP_INLINE_VISIBILITY
1198basic_ofstream<_CharT, _Traits>::basic_ofstream(const char* __s, ios_base::openmode __mode)
1199    : basic_ostream<char_type, traits_type>(&__sb_)
1200{
1201    if (__sb_.open(__s, __mode | ios_base::out) == 0)
1202        this->setstate(ios_base::failbit);
1203}
1204
1205template <class _CharT, class _Traits>
1206inline _LIBCPP_INLINE_VISIBILITY
1207basic_ofstream<_CharT, _Traits>::basic_ofstream(const string& __s, ios_base::openmode __mode)
1208    : basic_ostream<char_type, traits_type>(&__sb_)
1209{
1210    if (__sb_.open(__s, __mode | ios_base::out) == 0)
1211        this->setstate(ios_base::failbit);
1212}
1213#endif
1214
1215#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1216
1217template <class _CharT, class _Traits>
1218inline _LIBCPP_INLINE_VISIBILITY
1219basic_ofstream<_CharT, _Traits>::basic_ofstream(basic_ofstream&& __rhs)
1220    : basic_ostream<char_type, traits_type>(_VSTD::move(__rhs)),
1221      __sb_(_VSTD::move(__rhs.__sb_))
1222{
1223    this->set_rdbuf(&__sb_);
1224}
1225
1226template <class _CharT, class _Traits>
1227inline _LIBCPP_INLINE_VISIBILITY
1228basic_ofstream<_CharT, _Traits>&
1229basic_ofstream<_CharT, _Traits>::operator=(basic_ofstream&& __rhs)
1230{
1231    basic_ostream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
1232    __sb_ = _VSTD::move(__rhs.__sb_);
1233    return *this;
1234}
1235
1236#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
1237
1238template <class _CharT, class _Traits>
1239inline _LIBCPP_INLINE_VISIBILITY
1240void
1241basic_ofstream<_CharT, _Traits>::swap(basic_ofstream& __rhs)
1242{
1243    basic_ostream<char_type, traits_type>::swap(__rhs);
1244    __sb_.swap(__rhs.__sb_);
1245}
1246
1247template <class _CharT, class _Traits>
1248inline _LIBCPP_INLINE_VISIBILITY
1249void
1250swap(basic_ofstream<_CharT, _Traits>& __x, basic_ofstream<_CharT, _Traits>& __y)
1251{
1252    __x.swap(__y);
1253}
1254
1255template <class _CharT, class _Traits>
1256inline _LIBCPP_INLINE_VISIBILITY
1257basic_filebuf<_CharT, _Traits>*
1258basic_ofstream<_CharT, _Traits>::rdbuf() const
1259{
1260    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
1261}
1262
1263template <class _CharT, class _Traits>
1264inline _LIBCPP_INLINE_VISIBILITY
1265bool
1266basic_ofstream<_CharT, _Traits>::is_open() const
1267{
1268    return __sb_.is_open();
1269}
1270
1271#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
1272template <class _CharT, class _Traits>
1273void
1274basic_ofstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
1275{
1276    if (__sb_.open(__s, __mode | ios_base::out))
1277        this->clear();
1278    else
1279        this->setstate(ios_base::failbit);
1280}
1281
1282template <class _CharT, class _Traits>
1283void
1284basic_ofstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
1285{
1286    if (__sb_.open(__s, __mode | ios_base::out))
1287        this->clear();
1288    else
1289        this->setstate(ios_base::failbit);
1290}
1291#endif
1292
1293template <class _CharT, class _Traits>
1294inline _LIBCPP_INLINE_VISIBILITY
1295void
1296basic_ofstream<_CharT, _Traits>::close()
1297{
1298    if (__sb_.close() == 0)
1299        this->setstate(ios_base::failbit);
1300}
1301
1302// basic_fstream
1303
1304template <class _CharT, class _Traits>
1305class _LIBCPP_TYPE_VIS_ONLY basic_fstream
1306    : public basic_iostream<_CharT, _Traits>
1307{
1308public:
1309    typedef _CharT                         char_type;
1310    typedef _Traits                        traits_type;
1311    typedef typename traits_type::int_type int_type;
1312    typedef typename traits_type::pos_type pos_type;
1313    typedef typename traits_type::off_type off_type;
1314
1315    basic_fstream();
1316#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
1317    explicit basic_fstream(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
1318    explicit basic_fstream(const string& __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
1319#endif
1320#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1321    basic_fstream(basic_fstream&& __rhs);
1322#endif
1323
1324#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1325    basic_fstream& operator=(basic_fstream&& __rhs);
1326#endif
1327    void swap(basic_fstream& __rhs);
1328
1329    basic_filebuf<char_type, traits_type>* rdbuf() const;
1330    bool is_open() const;
1331#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
1332    void open(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
1333    void open(const string& __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
1334#endif
1335    void close();
1336
1337private:
1338    basic_filebuf<char_type, traits_type> __sb_;
1339};
1340
1341template <class _CharT, class _Traits>
1342inline _LIBCPP_INLINE_VISIBILITY
1343basic_fstream<_CharT, _Traits>::basic_fstream()
1344    : basic_iostream<char_type, traits_type>(&__sb_)
1345{
1346}
1347
1348#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
1349template <class _CharT, class _Traits>
1350inline _LIBCPP_INLINE_VISIBILITY
1351basic_fstream<_CharT, _Traits>::basic_fstream(const char* __s, ios_base::openmode __mode)
1352    : basic_iostream<char_type, traits_type>(&__sb_)
1353{
1354    if (__sb_.open(__s, __mode) == 0)
1355        this->setstate(ios_base::failbit);
1356}
1357
1358template <class _CharT, class _Traits>
1359inline _LIBCPP_INLINE_VISIBILITY
1360basic_fstream<_CharT, _Traits>::basic_fstream(const string& __s, ios_base::openmode __mode)
1361    : basic_iostream<char_type, traits_type>(&__sb_)
1362{
1363    if (__sb_.open(__s, __mode) == 0)
1364        this->setstate(ios_base::failbit);
1365}
1366#endif
1367
1368#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
1369
1370template <class _CharT, class _Traits>
1371inline _LIBCPP_INLINE_VISIBILITY
1372basic_fstream<_CharT, _Traits>::basic_fstream(basic_fstream&& __rhs)
1373    : basic_iostream<char_type, traits_type>(_VSTD::move(__rhs)),
1374      __sb_(_VSTD::move(__rhs.__sb_))
1375{
1376    this->set_rdbuf(&__sb_);
1377}
1378
1379template <class _CharT, class _Traits>
1380inline _LIBCPP_INLINE_VISIBILITY
1381basic_fstream<_CharT, _Traits>&
1382basic_fstream<_CharT, _Traits>::operator=(basic_fstream&& __rhs)
1383{
1384    basic_iostream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
1385    __sb_ = _VSTD::move(__rhs.__sb_);
1386    return *this;
1387}
1388
1389#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
1390
1391template <class _CharT, class _Traits>
1392inline _LIBCPP_INLINE_VISIBILITY
1393void
1394basic_fstream<_CharT, _Traits>::swap(basic_fstream& __rhs)
1395{
1396    basic_iostream<char_type, traits_type>::swap(__rhs);
1397    __sb_.swap(__rhs.__sb_);
1398}
1399
1400template <class _CharT, class _Traits>
1401inline _LIBCPP_INLINE_VISIBILITY
1402void
1403swap(basic_fstream<_CharT, _Traits>& __x, basic_fstream<_CharT, _Traits>& __y)
1404{
1405    __x.swap(__y);
1406}
1407
1408template <class _CharT, class _Traits>
1409inline _LIBCPP_INLINE_VISIBILITY
1410basic_filebuf<_CharT, _Traits>*
1411basic_fstream<_CharT, _Traits>::rdbuf() const
1412{
1413    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
1414}
1415
1416template <class _CharT, class _Traits>
1417inline _LIBCPP_INLINE_VISIBILITY
1418bool
1419basic_fstream<_CharT, _Traits>::is_open() const
1420{
1421    return __sb_.is_open();
1422}
1423
1424#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
1425template <class _CharT, class _Traits>
1426void
1427basic_fstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
1428{
1429    if (__sb_.open(__s, __mode))
1430        this->clear();
1431    else
1432        this->setstate(ios_base::failbit);
1433}
1434
1435template <class _CharT, class _Traits>
1436void
1437basic_fstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
1438{
1439    if (__sb_.open(__s, __mode))
1440        this->clear();
1441    else
1442        this->setstate(ios_base::failbit);
1443}
1444#endif
1445
1446template <class _CharT, class _Traits>
1447inline _LIBCPP_INLINE_VISIBILITY
1448void
1449basic_fstream<_CharT, _Traits>::close()
1450{
1451    if (__sb_.close() == 0)
1452        this->setstate(ios_base::failbit);
1453}
1454
1455_LIBCPP_END_NAMESPACE_STD
1456
1457#endif  // _LIBCPP_FSTREAM
1458