Restoring authorship annotation for Andrey Khalyavin <halyavin@gmail.com>. Commit 2 of 2.

1 files changed, 1702 insertions, 1702 deletions

diff --git a/contrib/libs/cxxsupp/libcxx/include/fstream b/contrib/libs/cxxsupp/libcxx/include/fstream
index ccb9754760..d5a9aca37d 100644
--- a/contrib/libs/cxxsupp/libcxx/include/fstream
+++ b/contrib/libs/cxxsupp/libcxx/include/fstream
@@ -1,270 +1,270 @@
-// -*- C++ -*- 
-//===------------------------- fstream ------------------------------------===// 
-// 
+// -*- C++ -*-
+//===------------------------- fstream ------------------------------------===//
+//
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-// 
-//===----------------------------------------------------------------------===// 
- 
-#ifndef _LIBCPP_FSTREAM 
-#define _LIBCPP_FSTREAM 
- 
-/* 
-    fstream synopsis 
- 
-template <class charT, class traits = char_traits<charT> > 
-class basic_filebuf 
-    : public basic_streambuf<charT, traits> 
-{ 
-public: 
-    typedef charT                          char_type; 
-    typedef traits                         traits_type; 
-    typedef typename traits_type::int_type int_type; 
-    typedef typename traits_type::pos_type pos_type; 
-    typedef typename traits_type::off_type off_type; 
- 
-    // 27.9.1.2 Constructors/destructor: 
-    basic_filebuf(); 
-    basic_filebuf(basic_filebuf&& rhs); 
-    virtual ~basic_filebuf(); 
- 
-    // 27.9.1.3 Assign/swap: 
-    basic_filebuf& operator=(basic_filebuf&& rhs); 
-    void swap(basic_filebuf& rhs); 
- 
-    // 27.9.1.4 Members: 
-    bool is_open() const; 
-    basic_filebuf* open(const char* s, ios_base::openmode mode); 
-    basic_filebuf* open(const string& s, ios_base::openmode mode); 
-    basic_filebuf* open(const filesystem::path& p, ios_base::openmode mode); // C++17 
-    basic_filebuf* close(); 
- 
-protected: 
-    // 27.9.1.5 Overridden virtual functions: 
-    virtual streamsize showmanyc(); 
-    virtual int_type underflow(); 
-    virtual int_type uflow(); 
-    virtual int_type pbackfail(int_type c = traits_type::eof()); 
-    virtual int_type overflow (int_type c = traits_type::eof()); 
-    virtual basic_streambuf<char_type, traits_type>* setbuf(char_type* s, streamsize n); 
-    virtual pos_type seekoff(off_type off, ios_base::seekdir way, 
-                             ios_base::openmode which = ios_base::in | ios_base::out); 
-    virtual pos_type seekpos(pos_type sp, 
-                             ios_base::openmode which = ios_base::in | ios_base::out); 
-    virtual int sync(); 
-    virtual void imbue(const locale& loc); 
-}; 
- 
-template <class charT, class traits> 
-  void 
-  swap(basic_filebuf<charT, traits>& x, basic_filebuf<charT, traits>& y); 
- 
-typedef basic_filebuf<char>    filebuf; 
-typedef basic_filebuf<wchar_t> wfilebuf; 
- 
-template <class charT, class traits = char_traits<charT> > 
-class basic_ifstream 
-    : public basic_istream<charT,traits> 
-{ 
-public: 
-    typedef charT                          char_type; 
-    typedef traits                         traits_type; 
-    typedef typename traits_type::int_type int_type; 
-    typedef typename traits_type::pos_type pos_type; 
-    typedef typename traits_type::off_type off_type; 
- 
-    basic_ifstream(); 
-    explicit basic_ifstream(const char* s, ios_base::openmode mode = ios_base::in); 
-    explicit basic_ifstream(const string& s, ios_base::openmode mode = ios_base::in); 
-    explicit basic_ifstream(const filesystem::path& p, 
-                            ios_base::openmode mode = ios_base::in); // C++17 
-    basic_ifstream(basic_ifstream&& rhs); 
- 
-    basic_ifstream& operator=(basic_ifstream&& rhs); 
-    void swap(basic_ifstream& rhs); 
- 
-    basic_filebuf<char_type, traits_type>* rdbuf() const; 
-    bool is_open() const; 
-    void open(const char* s, ios_base::openmode mode = ios_base::in); 
-    void open(const string& s, ios_base::openmode mode = ios_base::in); 
-    void open(const filesystem::path& s, ios_base::openmode mode = ios_base::in); // C++17 
- 
-    void close(); 
-}; 
- 
-template <class charT, class traits> 
-  void 
-  swap(basic_ifstream<charT, traits>& x, basic_ifstream<charT, traits>& y); 
- 
-typedef basic_ifstream<char>    ifstream; 
-typedef basic_ifstream<wchar_t> wifstream; 
- 
-template <class charT, class traits = char_traits<charT> > 
-class basic_ofstream 
-    : public basic_ostream<charT,traits> 
-{ 
-public: 
-    typedef charT                          char_type; 
-    typedef traits                         traits_type; 
-    typedef typename traits_type::int_type int_type; 
-    typedef typename traits_type::pos_type pos_type; 
-    typedef typename traits_type::off_type off_type; 
- 
-    basic_ofstream(); 
-    explicit basic_ofstream(const char* s, ios_base::openmode mode = ios_base::out); 
-    explicit basic_ofstream(const string& s, ios_base::openmode mode = ios_base::out); 
-    explicit basic_ofstream(const filesystem::path& p, 
-                            ios_base::openmode mode = ios_base::out); // C++17 
-    basic_ofstream(basic_ofstream&& rhs); 
- 
-    basic_ofstream& operator=(basic_ofstream&& rhs); 
-    void swap(basic_ofstream& rhs); 
- 
-    basic_filebuf<char_type, traits_type>* rdbuf() const; 
-    bool is_open() const; 
-    void open(const char* s, ios_base::openmode mode = ios_base::out); 
-    void open(const string& s, ios_base::openmode mode = ios_base::out); 
-    void open(const filesystem::path& p, 
-              ios_base::openmode mode = ios_base::out); // C++17 
- 
-    void close(); 
-}; 
- 
-template <class charT, class traits> 
-  void 
-  swap(basic_ofstream<charT, traits>& x, basic_ofstream<charT, traits>& y); 
- 
-typedef basic_ofstream<char>    ofstream; 
-typedef basic_ofstream<wchar_t> wofstream; 
- 
-template <class charT, class traits=char_traits<charT> > 
-class basic_fstream 
-    : public basic_iostream<charT,traits> 
-{ 
-public: 
-    typedef charT                          char_type; 
-    typedef traits                         traits_type; 
-    typedef typename traits_type::int_type int_type; 
-    typedef typename traits_type::pos_type pos_type; 
-    typedef typename traits_type::off_type off_type; 
- 
-    basic_fstream(); 
-    explicit basic_fstream(const char* s, ios_base::openmode mode = ios_base::in|ios_base::out); 
-    explicit basic_fstream(const string& s, ios_base::openmode mode = ios_base::in|ios_base::out); 
-    explicit basic_fstream(const filesystem::path& p, 
-                           ios_base::openmode mode = ios_base::in|ios_base::out); C++17 
-    basic_fstream(basic_fstream&& rhs); 
- 
-    basic_fstream& operator=(basic_fstream&& rhs); 
-    void swap(basic_fstream& rhs); 
- 
-    basic_filebuf<char_type, traits_type>* rdbuf() const; 
-    bool is_open() const; 
-    void open(const char* s, ios_base::openmode mode = ios_base::in|ios_base::out); 
-    void open(const string& s, ios_base::openmode mode = ios_base::in|ios_base::out); 
-    void open(const filesystem::path& s, 
-              ios_base::openmode mode = ios_base::in|ios_base::out); // C++17 
- 
-    void close(); 
-}; 
- 
-template <class charT, class traits> 
-  void swap(basic_fstream<charT, traits>& x, basic_fstream<charT, traits>& y); 
- 
-typedef basic_fstream<char>    fstream; 
-typedef basic_fstream<wchar_t> wfstream; 
- 
-}  // std 
- 
-*/ 
- 
-#include <__availability> 
-#include <__config> 
-#include <__debug> 
-#include <__locale> 
-#include <cstdio> 
-#include <cstdlib> 
-#include <istream> 
-#include <ostream> 
- 
-#if !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY) 
-#include <filesystem> 
-#endif 
- 
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 
-#pragma GCC system_header 
-#endif 
- 
-_LIBCPP_PUSH_MACROS 
-#include <__undef_macros> 
- 
-#if defined(_LIBCPP_MSVCRT) || defined(_NEWLIB_VERSION) 
-#  define _LIBCPP_HAS_NO_OFF_T_FUNCTIONS 
-#endif 
- 
-_LIBCPP_BEGIN_NAMESPACE_STD 
- 
-template <class _CharT, class _Traits> 
-class _LIBCPP_TEMPLATE_VIS basic_filebuf 
-    : public basic_streambuf<_CharT, _Traits> 
-{ 
-public: 
-    typedef _CharT                           char_type; 
-    typedef _Traits                          traits_type; 
-    typedef typename traits_type::int_type   int_type; 
-    typedef typename traits_type::pos_type   pos_type; 
-    typedef typename traits_type::off_type   off_type; 
-    typedef typename traits_type::state_type state_type; 
- 
-    // 27.9.1.2 Constructors/destructor: 
-    basic_filebuf(); 
-    basic_filebuf(basic_filebuf&& __rhs); 
-    virtual ~basic_filebuf(); 
- 
-    // 27.9.1.3 Assign/swap: 
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_filebuf& operator=(basic_filebuf&& __rhs); 
-    void swap(basic_filebuf& __rhs); 
- 
-    // 27.9.1.4 Members: 
-    _LIBCPP_INLINE_VISIBILITY 
-    bool is_open() const; 
-    basic_filebuf* open(const char* __s, ios_base::openmode __mode); 
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR 
-    basic_filebuf* open(const wchar_t* __s, ios_base::openmode __mode); 
-#endif 
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_filebuf* open(const string& __s, ios_base::openmode __mode); 
- 
-#if _LIBCPP_STD_VER >= 17 && !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY) 
-    _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_INLINE_VISIBILITY 
-    basic_filebuf* open(const _VSTD_FS::path& __p, ios_base::openmode __mode) { 
-      return open(__p.c_str(), __mode); 
-    } 
-#endif 
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_filebuf* __open(int __fd, ios_base::openmode __mode); 
-    basic_filebuf* close(); 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    inline static const char* 
-    __make_mdstring(ios_base::openmode __mode) _NOEXCEPT; 
- 
-  protected: 
-    // 27.9.1.5 Overridden virtual functions: 
-    virtual int_type underflow(); 
-    virtual int_type pbackfail(int_type __c = traits_type::eof()); 
-    virtual int_type overflow (int_type __c = traits_type::eof()); 
-    virtual basic_streambuf<char_type, traits_type>* setbuf(char_type* __s, streamsize __n); 
-    virtual pos_type seekoff(off_type __off, ios_base::seekdir __way, 
-                             ios_base::openmode __wch = ios_base::in | ios_base::out); 
-    virtual pos_type seekpos(pos_type __sp, 
-                             ios_base::openmode __wch = ios_base::in | ios_base::out); 
-    virtual int sync(); 
-    virtual void imbue(const locale& __loc); 
- 
-private: 
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_FSTREAM
+#define _LIBCPP_FSTREAM
+
+/*
+    fstream synopsis
+
+template <class charT, class traits = char_traits<charT> >
+class basic_filebuf
+    : public basic_streambuf<charT, traits>
+{
+public:
+    typedef charT                          char_type;
+    typedef traits                         traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    // 27.9.1.2 Constructors/destructor:
+    basic_filebuf();
+    basic_filebuf(basic_filebuf&& rhs);
+    virtual ~basic_filebuf();
+
+    // 27.9.1.3 Assign/swap:
+    basic_filebuf& operator=(basic_filebuf&& rhs);
+    void swap(basic_filebuf& rhs);
+
+    // 27.9.1.4 Members:
+    bool is_open() const;
+    basic_filebuf* open(const char* s, ios_base::openmode mode);
+    basic_filebuf* open(const string& s, ios_base::openmode mode);
+    basic_filebuf* open(const filesystem::path& p, ios_base::openmode mode); // C++17
+    basic_filebuf* close();
+
+protected:
+    // 27.9.1.5 Overridden virtual functions:
+    virtual streamsize showmanyc();
+    virtual int_type underflow();
+    virtual int_type uflow();
+    virtual int_type pbackfail(int_type c = traits_type::eof());
+    virtual int_type overflow (int_type c = traits_type::eof());
+    virtual basic_streambuf<char_type, traits_type>* setbuf(char_type* s, streamsize n);
+    virtual pos_type seekoff(off_type off, ios_base::seekdir way,
+                             ios_base::openmode which = ios_base::in | ios_base::out);
+    virtual pos_type seekpos(pos_type sp,
+                             ios_base::openmode which = ios_base::in | ios_base::out);
+    virtual int sync();
+    virtual void imbue(const locale& loc);
+};
+
+template <class charT, class traits>
+  void
+  swap(basic_filebuf<charT, traits>& x, basic_filebuf<charT, traits>& y);
+
+typedef basic_filebuf<char>    filebuf;
+typedef basic_filebuf<wchar_t> wfilebuf;
+
+template <class charT, class traits = char_traits<charT> >
+class basic_ifstream
+    : public basic_istream<charT,traits>
+{
+public:
+    typedef charT                          char_type;
+    typedef traits                         traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    basic_ifstream();
+    explicit basic_ifstream(const char* s, ios_base::openmode mode = ios_base::in);
+    explicit basic_ifstream(const string& s, ios_base::openmode mode = ios_base::in);
+    explicit basic_ifstream(const filesystem::path& p,
+                            ios_base::openmode mode = ios_base::in); // C++17
+    basic_ifstream(basic_ifstream&& rhs);
+
+    basic_ifstream& operator=(basic_ifstream&& rhs);
+    void swap(basic_ifstream& rhs);
+
+    basic_filebuf<char_type, traits_type>* rdbuf() const;
+    bool is_open() const;
+    void open(const char* s, ios_base::openmode mode = ios_base::in);
+    void open(const string& s, ios_base::openmode mode = ios_base::in);
+    void open(const filesystem::path& s, ios_base::openmode mode = ios_base::in); // C++17
+
+    void close();
+};
+
+template <class charT, class traits>
+  void
+  swap(basic_ifstream<charT, traits>& x, basic_ifstream<charT, traits>& y);
+
+typedef basic_ifstream<char>    ifstream;
+typedef basic_ifstream<wchar_t> wifstream;
+
+template <class charT, class traits = char_traits<charT> >
+class basic_ofstream
+    : public basic_ostream<charT,traits>
+{
+public:
+    typedef charT                          char_type;
+    typedef traits                         traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    basic_ofstream();
+    explicit basic_ofstream(const char* s, ios_base::openmode mode = ios_base::out);
+    explicit basic_ofstream(const string& s, ios_base::openmode mode = ios_base::out);
+    explicit basic_ofstream(const filesystem::path& p,
+                            ios_base::openmode mode = ios_base::out); // C++17
+    basic_ofstream(basic_ofstream&& rhs);
+
+    basic_ofstream& operator=(basic_ofstream&& rhs);
+    void swap(basic_ofstream& rhs);
+
+    basic_filebuf<char_type, traits_type>* rdbuf() const;
+    bool is_open() const;
+    void open(const char* s, ios_base::openmode mode = ios_base::out);
+    void open(const string& s, ios_base::openmode mode = ios_base::out);
+    void open(const filesystem::path& p,
+              ios_base::openmode mode = ios_base::out); // C++17
+
+    void close();
+};
+
+template <class charT, class traits>
+  void
+  swap(basic_ofstream<charT, traits>& x, basic_ofstream<charT, traits>& y);
+
+typedef basic_ofstream<char>    ofstream;
+typedef basic_ofstream<wchar_t> wofstream;
+
+template <class charT, class traits=char_traits<charT> >
+class basic_fstream
+    : public basic_iostream<charT,traits>
+{
+public:
+    typedef charT                          char_type;
+    typedef traits                         traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    basic_fstream();
+    explicit basic_fstream(const char* s, ios_base::openmode mode = ios_base::in|ios_base::out);
+    explicit basic_fstream(const string& s, ios_base::openmode mode = ios_base::in|ios_base::out);
+    explicit basic_fstream(const filesystem::path& p,
+                           ios_base::openmode mode = ios_base::in|ios_base::out); C++17
+    basic_fstream(basic_fstream&& rhs);
+
+    basic_fstream& operator=(basic_fstream&& rhs);
+    void swap(basic_fstream& rhs);
+
+    basic_filebuf<char_type, traits_type>* rdbuf() const;
+    bool is_open() const;
+    void open(const char* s, ios_base::openmode mode = ios_base::in|ios_base::out);
+    void open(const string& s, ios_base::openmode mode = ios_base::in|ios_base::out);
+    void open(const filesystem::path& s,
+              ios_base::openmode mode = ios_base::in|ios_base::out); // C++17
+
+    void close();
+};
+
+template <class charT, class traits>
+  void swap(basic_fstream<charT, traits>& x, basic_fstream<charT, traits>& y);
+
+typedef basic_fstream<char>    fstream;
+typedef basic_fstream<wchar_t> wfstream;
+
+}  // std
+
+*/
+
+#include <__availability>
+#include <__config>
+#include <__debug>
+#include <__locale>
+#include <cstdio>
+#include <cstdlib>
+#include <istream>
+#include <ostream>
+
+#if !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY)
+#include <filesystem>
+#endif
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+#if defined(_LIBCPP_MSVCRT) || defined(_NEWLIB_VERSION)
+#  define _LIBCPP_HAS_NO_OFF_T_FUNCTIONS
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TEMPLATE_VIS basic_filebuf
+    : public basic_streambuf<_CharT, _Traits>
+{
+public:
+    typedef _CharT                           char_type;
+    typedef _Traits                          traits_type;
+    typedef typename traits_type::int_type   int_type;
+    typedef typename traits_type::pos_type   pos_type;
+    typedef typename traits_type::off_type   off_type;
+    typedef typename traits_type::state_type state_type;
+
+    // 27.9.1.2 Constructors/destructor:
+    basic_filebuf();
+    basic_filebuf(basic_filebuf&& __rhs);
+    virtual ~basic_filebuf();
+
+    // 27.9.1.3 Assign/swap:
+    _LIBCPP_INLINE_VISIBILITY
+    basic_filebuf& operator=(basic_filebuf&& __rhs);
+    void swap(basic_filebuf& __rhs);
+
+    // 27.9.1.4 Members:
+    _LIBCPP_INLINE_VISIBILITY
+    bool is_open() const;
+    basic_filebuf* open(const char* __s, ios_base::openmode __mode);
+#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
+    basic_filebuf* open(const wchar_t* __s, ios_base::openmode __mode);
+#endif
+    _LIBCPP_INLINE_VISIBILITY
+    basic_filebuf* open(const string& __s, ios_base::openmode __mode);
+
+#if _LIBCPP_STD_VER >= 17 && !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY)
+    _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_INLINE_VISIBILITY
+    basic_filebuf* open(const _VSTD_FS::path& __p, ios_base::openmode __mode) {
+      return open(__p.c_str(), __mode);
+    }
+#endif
+    _LIBCPP_INLINE_VISIBILITY
+    basic_filebuf* __open(int __fd, ios_base::openmode __mode);
+    basic_filebuf* close();
+
+    _LIBCPP_INLINE_VISIBILITY
+    inline static const char*
+    __make_mdstring(ios_base::openmode __mode) _NOEXCEPT;
+
+  protected:
+    // 27.9.1.5 Overridden virtual functions:
+    virtual int_type underflow();
+    virtual int_type pbackfail(int_type __c = traits_type::eof());
+    virtual int_type overflow (int_type __c = traits_type::eof());
+    virtual basic_streambuf<char_type, traits_type>* setbuf(char_type* __s, streamsize __n);
+    virtual pos_type seekoff(off_type __off, ios_base::seekdir __way,
+                             ios_base::openmode __wch = ios_base::in | ios_base::out);
+    virtual pos_type seekpos(pos_type __sp,
+                             ios_base::openmode __wch = ios_base::in | ios_base::out);
+    virtual int sync();
+    virtual void imbue(const locale& __loc);
+
+private:
   char* __extbuf_;
   const char* __extbufnext_;
   const char* __extbufend_;
@@ -281,1447 +281,1447 @@ private:
   bool __owns_eb_;
   bool __owns_ib_;
   bool __always_noconv_;
- 
+
   bool __read_mode();
   void __write_mode();
-}; 
- 
-template <class _CharT, class _Traits> 
-basic_filebuf<_CharT, _Traits>::basic_filebuf() 
-    : __extbuf_(nullptr), 
-      __extbufnext_(nullptr), 
-      __extbufend_(nullptr), 
-      __ebs_(0), 
-      __intbuf_(nullptr), 
-      __ibs_(0), 
-      __file_(nullptr), 
-      __cv_(nullptr), 
-      __st_(), 
-      __st_last_(), 
-      __om_(0), 
-      __cm_(0), 
-      __owns_eb_(false), 
-      __owns_ib_(false), 
-      __always_noconv_(false) 
-{ 
-    if (has_facet<codecvt<char_type, char, state_type> >(this->getloc())) 
-    { 
-        __cv_ = &use_facet<codecvt<char_type, char, state_type> >(this->getloc()); 
-        __always_noconv_ = __cv_->always_noconv(); 
-    } 
-    setbuf(nullptr, 4096); 
-} 
- 
-template <class _CharT, class _Traits> 
-basic_filebuf<_CharT, _Traits>::basic_filebuf(basic_filebuf&& __rhs) 
-    : basic_streambuf<_CharT, _Traits>(__rhs) 
-{ 
-    if (__rhs.__extbuf_ == __rhs.__extbuf_min_) 
-    { 
-        __extbuf_ = __extbuf_min_; 
-        __extbufnext_ = __extbuf_ + (__rhs.__extbufnext_ - __rhs.__extbuf_); 
-        __extbufend_ = __extbuf_ + (__rhs.__extbufend_ - __rhs.__extbuf_); 
-    } 
-    else 
-    { 
-        __extbuf_ = __rhs.__extbuf_; 
-        __extbufnext_ = __rhs.__extbufnext_; 
-        __extbufend_ = __rhs.__extbufend_; 
-    } 
-    __ebs_ = __rhs.__ebs_; 
-    __intbuf_ = __rhs.__intbuf_; 
-    __ibs_ = __rhs.__ibs_; 
-    __file_ = __rhs.__file_; 
-    __cv_ = __rhs.__cv_; 
-    __st_ = __rhs.__st_; 
-    __st_last_ = __rhs.__st_last_; 
-    __om_ = __rhs.__om_; 
-    __cm_ = __rhs.__cm_; 
-    __owns_eb_ = __rhs.__owns_eb_; 
-    __owns_ib_ = __rhs.__owns_ib_; 
-    __always_noconv_ = __rhs.__always_noconv_; 
-    if (__rhs.pbase()) 
-    { 
-        if (__rhs.pbase() == __rhs.__intbuf_) 
-            this->setp(__intbuf_, __intbuf_ + (__rhs. epptr() - __rhs.pbase())); 
-        else 
-            this->setp((char_type*)__extbuf_, 
-                       (char_type*)__extbuf_ + (__rhs. epptr() - __rhs.pbase())); 
-        this->__pbump(__rhs. pptr() - __rhs.pbase()); 
-    } 
-    else if (__rhs.eback()) 
-    { 
-        if (__rhs.eback() == __rhs.__intbuf_) 
-            this->setg(__intbuf_, __intbuf_ + (__rhs.gptr() - __rhs.eback()), 
-                                  __intbuf_ + (__rhs.egptr() - __rhs.eback())); 
-        else 
-            this->setg((char_type*)__extbuf_, 
-                       (char_type*)__extbuf_ + (__rhs.gptr() - __rhs.eback()), 
-                       (char_type*)__extbuf_ + (__rhs.egptr() - __rhs.eback())); 
-    } 
-    __rhs.__extbuf_ = nullptr; 
-    __rhs.__extbufnext_ = nullptr; 
-    __rhs.__extbufend_ = nullptr; 
-    __rhs.__ebs_ = 0; 
-    __rhs.__intbuf_ = 0; 
-    __rhs.__ibs_ = 0; 
-    __rhs.__file_ = nullptr; 
-    __rhs.__st_ = state_type(); 
-    __rhs.__st_last_ = state_type(); 
-    __rhs.__om_ = 0; 
-    __rhs.__cm_ = 0; 
-    __rhs.__owns_eb_ = false; 
-    __rhs.__owns_ib_ = false; 
-    __rhs.setg(0, 0, 0); 
-    __rhs.setp(0, 0); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_filebuf<_CharT, _Traits>& 
-basic_filebuf<_CharT, _Traits>::operator=(basic_filebuf&& __rhs) 
-{ 
-    close(); 
-    swap(__rhs); 
-    return *this; 
-} 
- 
-template <class _CharT, class _Traits> 
-basic_filebuf<_CharT, _Traits>::~basic_filebuf() 
-{ 
-#ifndef _LIBCPP_NO_EXCEPTIONS 
-    try 
-    { 
-#endif // _LIBCPP_NO_EXCEPTIONS 
-        close(); 
-#ifndef _LIBCPP_NO_EXCEPTIONS 
-    } 
-    catch (...) 
-    { 
-    } 
-#endif // _LIBCPP_NO_EXCEPTIONS 
-    if (__owns_eb_) 
-        delete [] __extbuf_; 
-    if (__owns_ib_) 
-        delete [] __intbuf_; 
-} 
- 
-template <class _CharT, class _Traits> 
-void 
-basic_filebuf<_CharT, _Traits>::swap(basic_filebuf& __rhs) 
-{ 
-    basic_streambuf<char_type, traits_type>::swap(__rhs); 
-    if (__extbuf_ != __extbuf_min_ && __rhs.__extbuf_ != __rhs.__extbuf_min_) 
-    { 
-        _VSTD::swap(__extbuf_, __rhs.__extbuf_); 
-        _VSTD::swap(__extbufnext_, __rhs.__extbufnext_); 
-        _VSTD::swap(__extbufend_, __rhs.__extbufend_); 
-    } 
-    else 
-    { 
-        ptrdiff_t __ln = __extbufnext_ - __extbuf_; 
-        ptrdiff_t __le = __extbufend_ - __extbuf_; 
-        ptrdiff_t __rn = __rhs.__extbufnext_ - __rhs.__extbuf_; 
-        ptrdiff_t __re = __rhs.__extbufend_ - __rhs.__extbuf_; 
-        if (__extbuf_ == __extbuf_min_ && __rhs.__extbuf_ != __rhs.__extbuf_min_) 
-        { 
-            __extbuf_ = __rhs.__extbuf_; 
-            __rhs.__extbuf_ = __rhs.__extbuf_min_; 
-        } 
-        else if (__extbuf_ != __extbuf_min_ && __rhs.__extbuf_ == __rhs.__extbuf_min_) 
-        { 
-            __rhs.__extbuf_ = __extbuf_; 
-            __extbuf_ = __extbuf_min_; 
-        } 
-        __extbufnext_ = __extbuf_ + __rn; 
-        __extbufend_ = __extbuf_ + __re; 
-        __rhs.__extbufnext_ = __rhs.__extbuf_ + __ln; 
-        __rhs.__extbufend_ = __rhs.__extbuf_ + __le; 
-    } 
-    _VSTD::swap(__ebs_, __rhs.__ebs_); 
-    _VSTD::swap(__intbuf_, __rhs.__intbuf_); 
-    _VSTD::swap(__ibs_, __rhs.__ibs_); 
-    _VSTD::swap(__file_, __rhs.__file_); 
-    _VSTD::swap(__cv_, __rhs.__cv_); 
-    _VSTD::swap(__st_, __rhs.__st_); 
-    _VSTD::swap(__st_last_, __rhs.__st_last_); 
-    _VSTD::swap(__om_, __rhs.__om_); 
-    _VSTD::swap(__cm_, __rhs.__cm_); 
-    _VSTD::swap(__owns_eb_, __rhs.__owns_eb_); 
-    _VSTD::swap(__owns_ib_, __rhs.__owns_ib_); 
-    _VSTD::swap(__always_noconv_, __rhs.__always_noconv_); 
-    if (this->eback() == (char_type*)__rhs.__extbuf_min_) 
-    { 
-        ptrdiff_t __n = this->gptr() - this->eback(); 
-        ptrdiff_t __e = this->egptr() - this->eback(); 
-        this->setg((char_type*)__extbuf_min_, 
-                   (char_type*)__extbuf_min_ + __n, 
-                   (char_type*)__extbuf_min_ + __e); 
-    } 
-    else if (this->pbase() == (char_type*)__rhs.__extbuf_min_) 
-    { 
-        ptrdiff_t __n = this->pptr() - this->pbase(); 
-        ptrdiff_t __e = this->epptr() - this->pbase(); 
-        this->setp((char_type*)__extbuf_min_, 
-                   (char_type*)__extbuf_min_ + __e); 
-        this->__pbump(__n); 
-    } 
-    if (__rhs.eback() == (char_type*)__extbuf_min_) 
-    { 
-        ptrdiff_t __n = __rhs.gptr() - __rhs.eback(); 
-        ptrdiff_t __e = __rhs.egptr() - __rhs.eback(); 
-        __rhs.setg((char_type*)__rhs.__extbuf_min_, 
-                   (char_type*)__rhs.__extbuf_min_ + __n, 
-                   (char_type*)__rhs.__extbuf_min_ + __e); 
-    } 
-    else if (__rhs.pbase() == (char_type*)__extbuf_min_) 
-    { 
-        ptrdiff_t __n = __rhs.pptr() - __rhs.pbase(); 
-        ptrdiff_t __e = __rhs.epptr() - __rhs.pbase(); 
-        __rhs.setp((char_type*)__rhs.__extbuf_min_, 
-                   (char_type*)__rhs.__extbuf_min_ + __e); 
-        __rhs.__pbump(__n); 
-    } 
-} 
- 
-template <class _CharT, class _Traits> 
-inline _LIBCPP_INLINE_VISIBILITY 
-void 
-swap(basic_filebuf<_CharT, _Traits>& __x, basic_filebuf<_CharT, _Traits>& __y) 
-{ 
-    __x.swap(__y); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-bool 
-basic_filebuf<_CharT, _Traits>::is_open() const 
-{ 
-    return __file_ != nullptr; 
-} 
- 
-template <class _CharT, class _Traits> 
-const char* basic_filebuf<_CharT, _Traits>::__make_mdstring( 
-    ios_base::openmode __mode) _NOEXCEPT { 
-  switch (__mode & ~ios_base::ate) { 
-  case ios_base::out: 
-  case ios_base::out | ios_base::trunc: 
-    return "w" _LIBCPP_FOPEN_CLOEXEC_MODE; 
-  case ios_base::out | ios_base::app: 
-  case ios_base::app: 
-    return "a" _LIBCPP_FOPEN_CLOEXEC_MODE; 
-  case ios_base::in: 
-    return "r" _LIBCPP_FOPEN_CLOEXEC_MODE; 
-  case ios_base::in | ios_base::out: 
-    return "r+" _LIBCPP_FOPEN_CLOEXEC_MODE; 
-  case ios_base::in | ios_base::out | ios_base::trunc: 
-    return "w+" _LIBCPP_FOPEN_CLOEXEC_MODE; 
-  case ios_base::in | ios_base::out | ios_base::app: 
-  case ios_base::in | ios_base::app: 
-    return "a+" _LIBCPP_FOPEN_CLOEXEC_MODE; 
-  case ios_base::out | ios_base::binary: 
-  case ios_base::out | ios_base::trunc | ios_base::binary: 
-    return "wb" _LIBCPP_FOPEN_CLOEXEC_MODE; 
-  case ios_base::out | ios_base::app | ios_base::binary: 
-  case ios_base::app | ios_base::binary: 
-    return "ab" _LIBCPP_FOPEN_CLOEXEC_MODE; 
-  case ios_base::in | ios_base::binary: 
-    return "rb" _LIBCPP_FOPEN_CLOEXEC_MODE; 
-  case ios_base::in | ios_base::out | ios_base::binary: 
-    return "r+b" _LIBCPP_FOPEN_CLOEXEC_MODE; 
-  case ios_base::in | ios_base::out | ios_base::trunc | ios_base::binary: 
-    return "w+b" _LIBCPP_FOPEN_CLOEXEC_MODE; 
-  case ios_base::in | ios_base::out | ios_base::app | ios_base::binary: 
-  case ios_base::in | ios_base::app | ios_base::binary: 
-    return "a+b" _LIBCPP_FOPEN_CLOEXEC_MODE; 
-  default: 
-    return nullptr; 
-  } 
-  _LIBCPP_UNREACHABLE(); 
-} 
- 
-template <class _CharT, class _Traits> 
-basic_filebuf<_CharT, _Traits>* 
-basic_filebuf<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode) 
-{ 
-    basic_filebuf<_CharT, _Traits>* __rt = nullptr; 
-    if (__file_ == nullptr) 
-    { 
-      if (const char* __mdstr = __make_mdstring(__mode)) { 
-        __rt = this; 
-        __file_ = fopen(__s, __mdstr); 
-        if (__file_) { 
-          __om_ = __mode; 
-          if (__mode & ios_base::ate) { 
-            if (fseek(__file_, 0, SEEK_END)) { 
-              fclose(__file_); 
-              __file_ = nullptr; 
-              __rt = nullptr; 
-            } 
-          } 
-        } else 
-          __rt = nullptr; 
-      } 
-    } 
-    return __rt; 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_filebuf<_CharT, _Traits>* 
-basic_filebuf<_CharT, _Traits>::__open(int __fd, ios_base::openmode __mode) { 
-  basic_filebuf<_CharT, _Traits>* __rt = nullptr; 
-  if (__file_ == nullptr) { 
-    if (const char* __mdstr = __make_mdstring(__mode)) { 
-      __rt = this; 
-      __file_ = fdopen(__fd, __mdstr); 
-      if (__file_) { 
-        __om_ = __mode; 
-        if (__mode & ios_base::ate) { 
-          if (fseek(__file_, 0, SEEK_END)) { 
-            fclose(__file_); 
-            __file_ = nullptr; 
-            __rt = nullptr; 
-          } 
-        } 
-      } else 
-        __rt = nullptr; 
-    } 
-  } 
-  return __rt; 
-} 
- 
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR 
-// This is basically the same as the char* overload except that it uses _wfopen 
-// and long mode strings. 
-template <class _CharT, class _Traits> 
-basic_filebuf<_CharT, _Traits>* 
-basic_filebuf<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode) 
-{ 
-    basic_filebuf<_CharT, _Traits>* __rt = nullptr; 
-    if (__file_ == nullptr) 
-    { 
-        __rt = this; 
-        const wchar_t* __mdstr; 
-        switch (__mode & ~ios_base::ate) 
-        { 
-        case ios_base::out: 
-        case ios_base::out | ios_base::trunc: 
-            __mdstr = L"w"; 
-            break; 
-        case ios_base::out | ios_base::app: 
-        case ios_base::app: 
-            __mdstr = L"a"; 
-            break; 
-        case ios_base::in: 
-            __mdstr = L"r"; 
-            break; 
-        case ios_base::in | ios_base::out: 
-            __mdstr = L"r+"; 
-            break; 
-        case ios_base::in | ios_base::out | ios_base::trunc: 
-            __mdstr = L"w+"; 
-            break; 
-        case ios_base::in | ios_base::out | ios_base::app: 
-        case ios_base::in | ios_base::app: 
-            __mdstr = L"a+"; 
-            break; 
-        case ios_base::out | ios_base::binary: 
-        case ios_base::out | ios_base::trunc | ios_base::binary: 
-            __mdstr = L"wb"; 
-            break; 
-        case ios_base::out | ios_base::app | ios_base::binary: 
-        case ios_base::app | ios_base::binary: 
-            __mdstr = L"ab"; 
-            break; 
-        case ios_base::in | ios_base::binary: 
-            __mdstr = L"rb"; 
-            break; 
-        case ios_base::in | ios_base::out | ios_base::binary: 
-            __mdstr = L"r+b"; 
-            break; 
-        case ios_base::in | ios_base::out | ios_base::trunc | ios_base::binary: 
-            __mdstr = L"w+b"; 
-            break; 
-        case ios_base::in | ios_base::out | ios_base::app | ios_base::binary: 
-        case ios_base::in | ios_base::app | ios_base::binary: 
-            __mdstr = L"a+b"; 
-            break; 
-        default: 
-            __rt = nullptr; 
-            break; 
-        } 
-        if (__rt) 
-        { 
-            __file_ = _wfopen(__s, __mdstr); 
-            if (__file_) 
-            { 
-                __om_ = __mode; 
-                if (__mode & ios_base::ate) 
-                { 
-                    if (fseek(__file_, 0, SEEK_END)) 
-                    { 
-                        fclose(__file_); 
-                        __file_ = nullptr; 
-                        __rt = nullptr; 
-                    } 
-                } 
-            } 
-            else 
-                __rt = nullptr; 
-        } 
-    } 
-    return __rt; 
-} 
-#endif 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_filebuf<_CharT, _Traits>* 
-basic_filebuf<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode) 
-{ 
-    return open(__s.c_str(), __mode); 
-} 
- 
-template <class _CharT, class _Traits> 
-basic_filebuf<_CharT, _Traits>* 
-basic_filebuf<_CharT, _Traits>::close() 
-{ 
-    basic_filebuf<_CharT, _Traits>* __rt = nullptr; 
-    if (__file_) 
-    { 
-        __rt = this; 
-        unique_ptr<FILE, int(*)(FILE*)> __h(__file_, fclose); 
-        if (sync()) 
-            __rt = nullptr; 
-        if (fclose(__h.release())) 
-            __rt = nullptr; 
-        __file_ = nullptr; 
+};
+
+template <class _CharT, class _Traits>
+basic_filebuf<_CharT, _Traits>::basic_filebuf()
+    : __extbuf_(nullptr),
+      __extbufnext_(nullptr),
+      __extbufend_(nullptr),
+      __ebs_(0),
+      __intbuf_(nullptr),
+      __ibs_(0),
+      __file_(nullptr),
+      __cv_(nullptr),
+      __st_(),
+      __st_last_(),
+      __om_(0),
+      __cm_(0),
+      __owns_eb_(false),
+      __owns_ib_(false),
+      __always_noconv_(false)
+{
+    if (has_facet<codecvt<char_type, char, state_type> >(this->getloc()))
+    {
+        __cv_ = &use_facet<codecvt<char_type, char, state_type> >(this->getloc());
+        __always_noconv_ = __cv_->always_noconv();
+    }
+    setbuf(nullptr, 4096);
+}
+
+template <class _CharT, class _Traits>
+basic_filebuf<_CharT, _Traits>::basic_filebuf(basic_filebuf&& __rhs)
+    : basic_streambuf<_CharT, _Traits>(__rhs)
+{
+    if (__rhs.__extbuf_ == __rhs.__extbuf_min_)
+    {
+        __extbuf_ = __extbuf_min_;
+        __extbufnext_ = __extbuf_ + (__rhs.__extbufnext_ - __rhs.__extbuf_);
+        __extbufend_ = __extbuf_ + (__rhs.__extbufend_ - __rhs.__extbuf_);
+    }
+    else
+    {
+        __extbuf_ = __rhs.__extbuf_;
+        __extbufnext_ = __rhs.__extbufnext_;
+        __extbufend_ = __rhs.__extbufend_;
+    }
+    __ebs_ = __rhs.__ebs_;
+    __intbuf_ = __rhs.__intbuf_;
+    __ibs_ = __rhs.__ibs_;
+    __file_ = __rhs.__file_;
+    __cv_ = __rhs.__cv_;
+    __st_ = __rhs.__st_;
+    __st_last_ = __rhs.__st_last_;
+    __om_ = __rhs.__om_;
+    __cm_ = __rhs.__cm_;
+    __owns_eb_ = __rhs.__owns_eb_;
+    __owns_ib_ = __rhs.__owns_ib_;
+    __always_noconv_ = __rhs.__always_noconv_;
+    if (__rhs.pbase())
+    {
+        if (__rhs.pbase() == __rhs.__intbuf_)
+            this->setp(__intbuf_, __intbuf_ + (__rhs. epptr() - __rhs.pbase()));
+        else
+            this->setp((char_type*)__extbuf_,
+                       (char_type*)__extbuf_ + (__rhs. epptr() - __rhs.pbase()));
+        this->__pbump(__rhs. pptr() - __rhs.pbase());
+    }
+    else if (__rhs.eback())
+    {
+        if (__rhs.eback() == __rhs.__intbuf_)
+            this->setg(__intbuf_, __intbuf_ + (__rhs.gptr() - __rhs.eback()),
+                                  __intbuf_ + (__rhs.egptr() - __rhs.eback()));
+        else
+            this->setg((char_type*)__extbuf_,
+                       (char_type*)__extbuf_ + (__rhs.gptr() - __rhs.eback()),
+                       (char_type*)__extbuf_ + (__rhs.egptr() - __rhs.eback()));
+    }
+    __rhs.__extbuf_ = nullptr;
+    __rhs.__extbufnext_ = nullptr;
+    __rhs.__extbufend_ = nullptr;
+    __rhs.__ebs_ = 0;
+    __rhs.__intbuf_ = 0;
+    __rhs.__ibs_ = 0;
+    __rhs.__file_ = nullptr;
+    __rhs.__st_ = state_type();
+    __rhs.__st_last_ = state_type();
+    __rhs.__om_ = 0;
+    __rhs.__cm_ = 0;
+    __rhs.__owns_eb_ = false;
+    __rhs.__owns_ib_ = false;
+    __rhs.setg(0, 0, 0);
+    __rhs.setp(0, 0);
+}
+
+template <class _CharT, class _Traits>
+inline
+basic_filebuf<_CharT, _Traits>&
+basic_filebuf<_CharT, _Traits>::operator=(basic_filebuf&& __rhs)
+{
+    close();
+    swap(__rhs);
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+basic_filebuf<_CharT, _Traits>::~basic_filebuf()
+{
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    try
+    {
+#endif // _LIBCPP_NO_EXCEPTIONS
+        close();
+#ifndef _LIBCPP_NO_EXCEPTIONS
+    }
+    catch (...)
+    {
+    }
+#endif // _LIBCPP_NO_EXCEPTIONS
+    if (__owns_eb_)
+        delete [] __extbuf_;
+    if (__owns_ib_)
+        delete [] __intbuf_;
+}
+
+template <class _CharT, class _Traits>
+void
+basic_filebuf<_CharT, _Traits>::swap(basic_filebuf& __rhs)
+{
+    basic_streambuf<char_type, traits_type>::swap(__rhs);
+    if (__extbuf_ != __extbuf_min_ && __rhs.__extbuf_ != __rhs.__extbuf_min_)
+    {
+        _VSTD::swap(__extbuf_, __rhs.__extbuf_);
+        _VSTD::swap(__extbufnext_, __rhs.__extbufnext_);
+        _VSTD::swap(__extbufend_, __rhs.__extbufend_);
+    }
+    else
+    {
+        ptrdiff_t __ln = __extbufnext_ - __extbuf_;
+        ptrdiff_t __le = __extbufend_ - __extbuf_;
+        ptrdiff_t __rn = __rhs.__extbufnext_ - __rhs.__extbuf_;
+        ptrdiff_t __re = __rhs.__extbufend_ - __rhs.__extbuf_;
+        if (__extbuf_ == __extbuf_min_ && __rhs.__extbuf_ != __rhs.__extbuf_min_)
+        {
+            __extbuf_ = __rhs.__extbuf_;
+            __rhs.__extbuf_ = __rhs.__extbuf_min_;
+        }
+        else if (__extbuf_ != __extbuf_min_ && __rhs.__extbuf_ == __rhs.__extbuf_min_)
+        {
+            __rhs.__extbuf_ = __extbuf_;
+            __extbuf_ = __extbuf_min_;
+        }
+        __extbufnext_ = __extbuf_ + __rn;
+        __extbufend_ = __extbuf_ + __re;
+        __rhs.__extbufnext_ = __rhs.__extbuf_ + __ln;
+        __rhs.__extbufend_ = __rhs.__extbuf_ + __le;
+    }
+    _VSTD::swap(__ebs_, __rhs.__ebs_);
+    _VSTD::swap(__intbuf_, __rhs.__intbuf_);
+    _VSTD::swap(__ibs_, __rhs.__ibs_);
+    _VSTD::swap(__file_, __rhs.__file_);
+    _VSTD::swap(__cv_, __rhs.__cv_);
+    _VSTD::swap(__st_, __rhs.__st_);
+    _VSTD::swap(__st_last_, __rhs.__st_last_);
+    _VSTD::swap(__om_, __rhs.__om_);
+    _VSTD::swap(__cm_, __rhs.__cm_);
+    _VSTD::swap(__owns_eb_, __rhs.__owns_eb_);
+    _VSTD::swap(__owns_ib_, __rhs.__owns_ib_);
+    _VSTD::swap(__always_noconv_, __rhs.__always_noconv_);
+    if (this->eback() == (char_type*)__rhs.__extbuf_min_)
+    {
+        ptrdiff_t __n = this->gptr() - this->eback();
+        ptrdiff_t __e = this->egptr() - this->eback();
+        this->setg((char_type*)__extbuf_min_,
+                   (char_type*)__extbuf_min_ + __n,
+                   (char_type*)__extbuf_min_ + __e);
+    }
+    else if (this->pbase() == (char_type*)__rhs.__extbuf_min_)
+    {
+        ptrdiff_t __n = this->pptr() - this->pbase();
+        ptrdiff_t __e = this->epptr() - this->pbase();
+        this->setp((char_type*)__extbuf_min_,
+                   (char_type*)__extbuf_min_ + __e);
+        this->__pbump(__n);
+    }
+    if (__rhs.eback() == (char_type*)__extbuf_min_)
+    {
+        ptrdiff_t __n = __rhs.gptr() - __rhs.eback();
+        ptrdiff_t __e = __rhs.egptr() - __rhs.eback();
+        __rhs.setg((char_type*)__rhs.__extbuf_min_,
+                   (char_type*)__rhs.__extbuf_min_ + __n,
+                   (char_type*)__rhs.__extbuf_min_ + __e);
+    }
+    else if (__rhs.pbase() == (char_type*)__extbuf_min_)
+    {
+        ptrdiff_t __n = __rhs.pptr() - __rhs.pbase();
+        ptrdiff_t __e = __rhs.epptr() - __rhs.pbase();
+        __rhs.setp((char_type*)__rhs.__extbuf_min_,
+                   (char_type*)__rhs.__extbuf_min_ + __e);
+        __rhs.__pbump(__n);
+    }
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(basic_filebuf<_CharT, _Traits>& __x, basic_filebuf<_CharT, _Traits>& __y)
+{
+    __x.swap(__y);
+}
+
+template <class _CharT, class _Traits>
+inline
+bool
+basic_filebuf<_CharT, _Traits>::is_open() const
+{
+    return __file_ != nullptr;
+}
+
+template <class _CharT, class _Traits>
+const char* basic_filebuf<_CharT, _Traits>::__make_mdstring(
+    ios_base::openmode __mode) _NOEXCEPT {
+  switch (__mode & ~ios_base::ate) {
+  case ios_base::out:
+  case ios_base::out | ios_base::trunc:
+    return "w" _LIBCPP_FOPEN_CLOEXEC_MODE;
+  case ios_base::out | ios_base::app:
+  case ios_base::app:
+    return "a" _LIBCPP_FOPEN_CLOEXEC_MODE;
+  case ios_base::in:
+    return "r" _LIBCPP_FOPEN_CLOEXEC_MODE;
+  case ios_base::in | ios_base::out:
+    return "r+" _LIBCPP_FOPEN_CLOEXEC_MODE;
+  case ios_base::in | ios_base::out | ios_base::trunc:
+    return "w+" _LIBCPP_FOPEN_CLOEXEC_MODE;
+  case ios_base::in | ios_base::out | ios_base::app:
+  case ios_base::in | ios_base::app:
+    return "a+" _LIBCPP_FOPEN_CLOEXEC_MODE;
+  case ios_base::out | ios_base::binary:
+  case ios_base::out | ios_base::trunc | ios_base::binary:
+    return "wb" _LIBCPP_FOPEN_CLOEXEC_MODE;
+  case ios_base::out | ios_base::app | ios_base::binary:
+  case ios_base::app | ios_base::binary:
+    return "ab" _LIBCPP_FOPEN_CLOEXEC_MODE;
+  case ios_base::in | ios_base::binary:
+    return "rb" _LIBCPP_FOPEN_CLOEXEC_MODE;
+  case ios_base::in | ios_base::out | ios_base::binary:
+    return "r+b" _LIBCPP_FOPEN_CLOEXEC_MODE;
+  case ios_base::in | ios_base::out | ios_base::trunc | ios_base::binary:
+    return "w+b" _LIBCPP_FOPEN_CLOEXEC_MODE;
+  case ios_base::in | ios_base::out | ios_base::app | ios_base::binary:
+  case ios_base::in | ios_base::app | ios_base::binary:
+    return "a+b" _LIBCPP_FOPEN_CLOEXEC_MODE;
+  default:
+    return nullptr;
+  }
+  _LIBCPP_UNREACHABLE();
+}
+
+template <class _CharT, class _Traits>
+basic_filebuf<_CharT, _Traits>*
+basic_filebuf<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
+{
+    basic_filebuf<_CharT, _Traits>* __rt = nullptr;
+    if (__file_ == nullptr)
+    {
+      if (const char* __mdstr = __make_mdstring(__mode)) {
+        __rt = this;
+        __file_ = fopen(__s, __mdstr);
+        if (__file_) {
+          __om_ = __mode;
+          if (__mode & ios_base::ate) {
+            if (fseek(__file_, 0, SEEK_END)) {
+              fclose(__file_);
+              __file_ = nullptr;
+              __rt = nullptr;
+            }
+          }
+        } else
+          __rt = nullptr;
+      }
+    }
+    return __rt;
+}
+
+template <class _CharT, class _Traits>
+inline
+basic_filebuf<_CharT, _Traits>*
+basic_filebuf<_CharT, _Traits>::__open(int __fd, ios_base::openmode __mode) {
+  basic_filebuf<_CharT, _Traits>* __rt = nullptr;
+  if (__file_ == nullptr) {
+    if (const char* __mdstr = __make_mdstring(__mode)) {
+      __rt = this;
+      __file_ = fdopen(__fd, __mdstr);
+      if (__file_) {
+        __om_ = __mode;
+        if (__mode & ios_base::ate) {
+          if (fseek(__file_, 0, SEEK_END)) {
+            fclose(__file_);
+            __file_ = nullptr;
+            __rt = nullptr;
+          }
+        }
+      } else
+        __rt = nullptr;
+    }
+  }
+  return __rt;
+}
+
+#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
+// This is basically the same as the char* overload except that it uses _wfopen
+// and long mode strings.
+template <class _CharT, class _Traits>
+basic_filebuf<_CharT, _Traits>*
+basic_filebuf<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode)
+{
+    basic_filebuf<_CharT, _Traits>* __rt = nullptr;
+    if (__file_ == nullptr)
+    {
+        __rt = this;
+        const wchar_t* __mdstr;
+        switch (__mode & ~ios_base::ate)
+        {
+        case ios_base::out:
+        case ios_base::out | ios_base::trunc:
+            __mdstr = L"w";
+            break;
+        case ios_base::out | ios_base::app:
+        case ios_base::app:
+            __mdstr = L"a";
+            break;
+        case ios_base::in:
+            __mdstr = L"r";
+            break;
+        case ios_base::in | ios_base::out:
+            __mdstr = L"r+";
+            break;
+        case ios_base::in | ios_base::out | ios_base::trunc:
+            __mdstr = L"w+";
+            break;
+        case ios_base::in | ios_base::out | ios_base::app:
+        case ios_base::in | ios_base::app:
+            __mdstr = L"a+";
+            break;
+        case ios_base::out | ios_base::binary:
+        case ios_base::out | ios_base::trunc | ios_base::binary:
+            __mdstr = L"wb";
+            break;
+        case ios_base::out | ios_base::app | ios_base::binary:
+        case ios_base::app | ios_base::binary:
+            __mdstr = L"ab";
+            break;
+        case ios_base::in | ios_base::binary:
+            __mdstr = L"rb";
+            break;
+        case ios_base::in | ios_base::out | ios_base::binary:
+            __mdstr = L"r+b";
+            break;
+        case ios_base::in | ios_base::out | ios_base::trunc | ios_base::binary:
+            __mdstr = L"w+b";
+            break;
+        case ios_base::in | ios_base::out | ios_base::app | ios_base::binary:
+        case ios_base::in | ios_base::app | ios_base::binary:
+            __mdstr = L"a+b";
+            break;
+        default:
+            __rt = nullptr;
+            break;
+        }
+        if (__rt)
+        {
+            __file_ = _wfopen(__s, __mdstr);
+            if (__file_)
+            {
+                __om_ = __mode;
+                if (__mode & ios_base::ate)
+                {
+                    if (fseek(__file_, 0, SEEK_END))
+                    {
+                        fclose(__file_);
+                        __file_ = nullptr;
+                        __rt = nullptr;
+                    }
+                }
+            }
+            else
+                __rt = nullptr;
+        }
+    }
+    return __rt;
+}
+#endif
+
+template <class _CharT, class _Traits>
+inline
+basic_filebuf<_CharT, _Traits>*
+basic_filebuf<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
+{
+    return open(__s.c_str(), __mode);
+}
+
+template <class _CharT, class _Traits>
+basic_filebuf<_CharT, _Traits>*
+basic_filebuf<_CharT, _Traits>::close()
+{
+    basic_filebuf<_CharT, _Traits>* __rt = nullptr;
+    if (__file_)
+    {
+        __rt = this;
+        unique_ptr<FILE, int(*)(FILE*)> __h(__file_, fclose);
+        if (sync())
+            __rt = nullptr;
+        if (fclose(__h.release()))
+            __rt = nullptr;
+        __file_ = nullptr;
         setbuf(0, 0);
-    } 
-    return __rt; 
-} 
- 
-template <class _CharT, class _Traits> 
-typename basic_filebuf<_CharT, _Traits>::int_type 
-basic_filebuf<_CharT, _Traits>::underflow() 
-{ 
-    if (__file_ == nullptr) 
-        return traits_type::eof(); 
-    bool __initial = __read_mode(); 
-    char_type __1buf; 
-    if (this->gptr() == nullptr) 
-        this->setg(&__1buf, &__1buf+1, &__1buf+1); 
-    const size_t __unget_sz = __initial ? 0 : min<size_t>((this->egptr() - this->eback()) / 2, 4); 
-    int_type __c = traits_type::eof(); 
-    if (this->gptr() == this->egptr()) 
-    { 
-        _VSTD::memmove(this->eback(), this->egptr() - __unget_sz, __unget_sz * sizeof(char_type)); 
-        if (__always_noconv_) 
-        { 
-            size_t __nmemb = static_cast<size_t>(this->egptr() - this->eback() - __unget_sz); 
-            __nmemb = fread(this->eback() + __unget_sz, 1, __nmemb, __file_); 
-            if (__nmemb != 0) 
-            { 
-                this->setg(this->eback(), 
-                           this->eback() + __unget_sz, 
-                           this->eback() + __unget_sz + __nmemb); 
-                __c = traits_type::to_int_type(*this->gptr()); 
-            } 
-        } 
-        else 
-        { 
-            _LIBCPP_ASSERT ( !(__extbufnext_ == NULL && (__extbufend_ != __extbufnext_)), "underflow moving from NULL" ); 
-            if (__extbufend_ != __extbufnext_) 
-                _VSTD::memmove(__extbuf_, __extbufnext_, __extbufend_ - __extbufnext_); 
-            __extbufnext_ = __extbuf_ + (__extbufend_ - __extbufnext_); 
-            __extbufend_ = __extbuf_ + (__extbuf_ == __extbuf_min_ ? sizeof(__extbuf_min_) : __ebs_); 
-            size_t __nmemb = _VSTD::min(static_cast<size_t>(__ibs_ - __unget_sz), 
-                                 static_cast<size_t>(__extbufend_ - __extbufnext_)); 
-            codecvt_base::result __r; 
-            __st_last_ = __st_; 
-            size_t __nr = fread((void*) const_cast<char *>(__extbufnext_), 1, __nmemb, __file_); 
-            if (__nr != 0) 
-            { 
-                if (!__cv_) 
-                    __throw_bad_cast(); 
- 
-                __extbufend_ = __extbufnext_ + __nr; 
-                char_type*  __inext; 
-                __r = __cv_->in(__st_, __extbuf_, __extbufend_, __extbufnext_, 
-                                       this->eback() + __unget_sz, 
-                                       this->eback() + __ibs_, __inext); 
-                if (__r == codecvt_base::noconv) 
-                { 
-                    this->setg((char_type*)__extbuf_, (char_type*)__extbuf_, 
-                                          (char_type*)const_cast<char *>(__extbufend_)); 
-                    __c = traits_type::to_int_type(*this->gptr()); 
-                } 
-                else if (__inext != this->eback() + __unget_sz) 
-                { 
-                    this->setg(this->eback(), this->eback() + __unget_sz, __inext); 
-                    __c = traits_type::to_int_type(*this->gptr()); 
-                } 
-            } 
-        } 
-    } 
-    else 
-        __c = traits_type::to_int_type(*this->gptr()); 
-    if (this->eback() == &__1buf) 
-        this->setg(nullptr, nullptr, nullptr); 
-    return __c; 
-} 
- 
-template <class _CharT, class _Traits> 
-typename basic_filebuf<_CharT, _Traits>::int_type 
-basic_filebuf<_CharT, _Traits>::pbackfail(int_type __c) 
-{ 
-    if (__file_ && this->eback() < this->gptr()) 
-    { 
-        if (traits_type::eq_int_type(__c, traits_type::eof())) 
-        { 
-            this->gbump(-1); 
-            return traits_type::not_eof(__c); 
-        } 
-        if ((__om_ & ios_base::out) || 
-            traits_type::eq(traits_type::to_char_type(__c), this->gptr()[-1])) 
-        { 
-            this->gbump(-1); 
-            *this->gptr() = traits_type::to_char_type(__c); 
-            return __c; 
-        } 
-    } 
-    return traits_type::eof(); 
-} 
- 
-template <class _CharT, class _Traits> 
-typename basic_filebuf<_CharT, _Traits>::int_type 
-basic_filebuf<_CharT, _Traits>::overflow(int_type __c) 
-{ 
-    if (__file_ == nullptr) 
-        return traits_type::eof(); 
-    __write_mode(); 
-    char_type __1buf; 
-    char_type* __pb_save = this->pbase(); 
-    char_type* __epb_save = this->epptr(); 
-    if (!traits_type::eq_int_type(__c, traits_type::eof())) 
-    { 
-        if (this->pptr() == nullptr) 
-            this->setp(&__1buf, &__1buf+1); 
-        *this->pptr() = traits_type::to_char_type(__c); 
-        this->pbump(1); 
-    } 
-    if (this->pptr() != this->pbase()) 
-    { 
-        if (__always_noconv_) 
-        { 
-            size_t __nmemb = static_cast<size_t>(this->pptr() - this->pbase()); 
-            if (fwrite(this->pbase(), sizeof(char_type), __nmemb, __file_) != __nmemb) 
-                return traits_type::eof(); 
-        } 
-        else 
-        { 
-            char* __extbe = __extbuf_; 
-            codecvt_base::result __r; 
-            do 
-            { 
-                if (!__cv_) 
-                    __throw_bad_cast(); 
- 
-                const char_type* __e; 
-                __r = __cv_->out(__st_, this->pbase(), this->pptr(), __e, 
-                                        __extbuf_, __extbuf_ + __ebs_, __extbe); 
-                if (__e == this->pbase()) 
-                    return traits_type::eof(); 
-                if (__r == codecvt_base::noconv) 
-                { 
-                    size_t __nmemb = static_cast<size_t>(this->pptr() - this->pbase()); 
-                    if (fwrite(this->pbase(), 1, __nmemb, __file_) != __nmemb) 
-                        return traits_type::eof(); 
-                } 
-                else if (__r == codecvt_base::ok || __r == codecvt_base::partial) 
-                { 
-                    size_t __nmemb = static_cast<size_t>(__extbe - __extbuf_); 
-                    if (fwrite(__extbuf_, 1, __nmemb, __file_) != __nmemb) 
-                        return traits_type::eof(); 
-                    if (__r == codecvt_base::partial) 
-                    { 
-                        this->setp(const_cast<char_type*>(__e), this->pptr()); 
-                        this->__pbump(this->epptr() - this->pbase()); 
-                    } 
-                } 
-                else 
-                    return traits_type::eof(); 
-            } while (__r == codecvt_base::partial); 
-        } 
-        this->setp(__pb_save, __epb_save); 
-    } 
-    return traits_type::not_eof(__c); 
-} 
- 
-template <class _CharT, class _Traits> 
-basic_streambuf<_CharT, _Traits>* 
-basic_filebuf<_CharT, _Traits>::setbuf(char_type* __s, streamsize __n) 
-{ 
-    this->setg(nullptr, nullptr, nullptr); 
-    this->setp(nullptr, nullptr); 
-    if (__owns_eb_) 
-        delete [] __extbuf_; 
-    if (__owns_ib_) 
-        delete [] __intbuf_; 
-    __ebs_ = __n; 
-    if (__ebs_ > sizeof(__extbuf_min_)) 
-    { 
-        if (__always_noconv_ && __s) 
-        { 
-            __extbuf_ = (char*)__s; 
-            __owns_eb_ = false; 
-        } 
-        else 
-        { 
-            __extbuf_ = new char[__ebs_]; 
-            __owns_eb_ = true; 
-        } 
-    } 
-    else 
-    { 
-        __extbuf_ = __extbuf_min_; 
-        __ebs_ = sizeof(__extbuf_min_); 
-        __owns_eb_ = false; 
-    } 
-    if (!__always_noconv_) 
-    { 
-        __ibs_ = max<streamsize>(__n, sizeof(__extbuf_min_)); 
-        if (__s && __ibs_ >= sizeof(__extbuf_min_)) 
-        { 
-            __intbuf_ = __s; 
-            __owns_ib_ = false; 
-        } 
-        else 
-        { 
-            __intbuf_ = new char_type[__ibs_]; 
-            __owns_ib_ = true; 
-        } 
-    } 
-    else 
-    { 
-        __ibs_ = 0; 
-        __intbuf_ = nullptr; 
-        __owns_ib_ = false; 
-    } 
-    return this; 
-} 
- 
-template <class _CharT, class _Traits> 
-typename basic_filebuf<_CharT, _Traits>::pos_type 
-basic_filebuf<_CharT, _Traits>::seekoff(off_type __off, ios_base::seekdir __way, 
-                                        ios_base::openmode) 
-{ 
-    if (!__cv_) 
-        __throw_bad_cast(); 
- 
-    int __width = __cv_->encoding(); 
-    if (__file_ == nullptr || (__width <= 0 && __off != 0) || sync()) 
-        return pos_type(off_type(-1)); 
-    // __width > 0 || __off == 0 
-    int __whence; 
-    switch (__way) 
-    { 
-    case ios_base::beg: 
-        __whence = SEEK_SET; 
-        break; 
-    case ios_base::cur: 
-        __whence = SEEK_CUR; 
-        break; 
-    case ios_base::end: 
-        __whence = SEEK_END; 
-        break; 
-    default: 
-        return pos_type(off_type(-1)); 
-    } 
+    }
+    return __rt;
+}
+
+template <class _CharT, class _Traits>
+typename basic_filebuf<_CharT, _Traits>::int_type
+basic_filebuf<_CharT, _Traits>::underflow()
+{
+    if (__file_ == nullptr)
+        return traits_type::eof();
+    bool __initial = __read_mode();
+    char_type __1buf;
+    if (this->gptr() == nullptr)
+        this->setg(&__1buf, &__1buf+1, &__1buf+1);
+    const size_t __unget_sz = __initial ? 0 : min<size_t>((this->egptr() - this->eback()) / 2, 4);
+    int_type __c = traits_type::eof();
+    if (this->gptr() == this->egptr())
+    {
+        _VSTD::memmove(this->eback(), this->egptr() - __unget_sz, __unget_sz * sizeof(char_type));
+        if (__always_noconv_)
+        {
+            size_t __nmemb = static_cast<size_t>(this->egptr() - this->eback() - __unget_sz);
+            __nmemb = fread(this->eback() + __unget_sz, 1, __nmemb, __file_);
+            if (__nmemb != 0)
+            {
+                this->setg(this->eback(),
+                           this->eback() + __unget_sz,
+                           this->eback() + __unget_sz + __nmemb);
+                __c = traits_type::to_int_type(*this->gptr());
+            }
+        }
+        else
+        {
+            _LIBCPP_ASSERT ( !(__extbufnext_ == NULL && (__extbufend_ != __extbufnext_)), "underflow moving from NULL" );
+            if (__extbufend_ != __extbufnext_)
+                _VSTD::memmove(__extbuf_, __extbufnext_, __extbufend_ - __extbufnext_);
+            __extbufnext_ = __extbuf_ + (__extbufend_ - __extbufnext_);
+            __extbufend_ = __extbuf_ + (__extbuf_ == __extbuf_min_ ? sizeof(__extbuf_min_) : __ebs_);
+            size_t __nmemb = _VSTD::min(static_cast<size_t>(__ibs_ - __unget_sz),
+                                 static_cast<size_t>(__extbufend_ - __extbufnext_));
+            codecvt_base::result __r;
+            __st_last_ = __st_;
+            size_t __nr = fread((void*) const_cast<char *>(__extbufnext_), 1, __nmemb, __file_);
+            if (__nr != 0)
+            {
+                if (!__cv_)
+                    __throw_bad_cast();
+
+                __extbufend_ = __extbufnext_ + __nr;
+                char_type*  __inext;
+                __r = __cv_->in(__st_, __extbuf_, __extbufend_, __extbufnext_,
+                                       this->eback() + __unget_sz,
+                                       this->eback() + __ibs_, __inext);
+                if (__r == codecvt_base::noconv)
+                {
+                    this->setg((char_type*)__extbuf_, (char_type*)__extbuf_,
+                                          (char_type*)const_cast<char *>(__extbufend_));
+                    __c = traits_type::to_int_type(*this->gptr());
+                }
+                else if (__inext != this->eback() + __unget_sz)
+                {
+                    this->setg(this->eback(), this->eback() + __unget_sz, __inext);
+                    __c = traits_type::to_int_type(*this->gptr());
+                }
+            }
+        }
+    }
+    else
+        __c = traits_type::to_int_type(*this->gptr());
+    if (this->eback() == &__1buf)
+        this->setg(nullptr, nullptr, nullptr);
+    return __c;
+}
+
+template <class _CharT, class _Traits>
+typename basic_filebuf<_CharT, _Traits>::int_type
+basic_filebuf<_CharT, _Traits>::pbackfail(int_type __c)
+{
+    if (__file_ && this->eback() < this->gptr())
+    {
+        if (traits_type::eq_int_type(__c, traits_type::eof()))
+        {
+            this->gbump(-1);
+            return traits_type::not_eof(__c);
+        }
+        if ((__om_ & ios_base::out) ||
+            traits_type::eq(traits_type::to_char_type(__c), this->gptr()[-1]))
+        {
+            this->gbump(-1);
+            *this->gptr() = traits_type::to_char_type(__c);
+            return __c;
+        }
+    }
+    return traits_type::eof();
+}
+
+template <class _CharT, class _Traits>
+typename basic_filebuf<_CharT, _Traits>::int_type
+basic_filebuf<_CharT, _Traits>::overflow(int_type __c)
+{
+    if (__file_ == nullptr)
+        return traits_type::eof();
+    __write_mode();
+    char_type __1buf;
+    char_type* __pb_save = this->pbase();
+    char_type* __epb_save = this->epptr();
+    if (!traits_type::eq_int_type(__c, traits_type::eof()))
+    {
+        if (this->pptr() == nullptr)
+            this->setp(&__1buf, &__1buf+1);
+        *this->pptr() = traits_type::to_char_type(__c);
+        this->pbump(1);
+    }
+    if (this->pptr() != this->pbase())
+    {
+        if (__always_noconv_)
+        {
+            size_t __nmemb = static_cast<size_t>(this->pptr() - this->pbase());
+            if (fwrite(this->pbase(), sizeof(char_type), __nmemb, __file_) != __nmemb)
+                return traits_type::eof();
+        }
+        else
+        {
+            char* __extbe = __extbuf_;
+            codecvt_base::result __r;
+            do
+            {
+                if (!__cv_)
+                    __throw_bad_cast();
+
+                const char_type* __e;
+                __r = __cv_->out(__st_, this->pbase(), this->pptr(), __e,
+                                        __extbuf_, __extbuf_ + __ebs_, __extbe);
+                if (__e == this->pbase())
+                    return traits_type::eof();
+                if (__r == codecvt_base::noconv)
+                {
+                    size_t __nmemb = static_cast<size_t>(this->pptr() - this->pbase());
+                    if (fwrite(this->pbase(), 1, __nmemb, __file_) != __nmemb)
+                        return traits_type::eof();
+                }
+                else if (__r == codecvt_base::ok || __r == codecvt_base::partial)
+                {
+                    size_t __nmemb = static_cast<size_t>(__extbe - __extbuf_);
+                    if (fwrite(__extbuf_, 1, __nmemb, __file_) != __nmemb)
+                        return traits_type::eof();
+                    if (__r == codecvt_base::partial)
+                    {
+                        this->setp(const_cast<char_type*>(__e), this->pptr());
+                        this->__pbump(this->epptr() - this->pbase());
+                    }
+                }
+                else
+                    return traits_type::eof();
+            } while (__r == codecvt_base::partial);
+        }
+        this->setp(__pb_save, __epb_save);
+    }
+    return traits_type::not_eof(__c);
+}
+
+template <class _CharT, class _Traits>
+basic_streambuf<_CharT, _Traits>*
+basic_filebuf<_CharT, _Traits>::setbuf(char_type* __s, streamsize __n)
+{
+    this->setg(nullptr, nullptr, nullptr);
+    this->setp(nullptr, nullptr);
+    if (__owns_eb_)
+        delete [] __extbuf_;
+    if (__owns_ib_)
+        delete [] __intbuf_;
+    __ebs_ = __n;
+    if (__ebs_ > sizeof(__extbuf_min_))
+    {
+        if (__always_noconv_ && __s)
+        {
+            __extbuf_ = (char*)__s;
+            __owns_eb_ = false;
+        }
+        else
+        {
+            __extbuf_ = new char[__ebs_];
+            __owns_eb_ = true;
+        }
+    }
+    else
+    {
+        __extbuf_ = __extbuf_min_;
+        __ebs_ = sizeof(__extbuf_min_);
+        __owns_eb_ = false;
+    }
+    if (!__always_noconv_)
+    {
+        __ibs_ = max<streamsize>(__n, sizeof(__extbuf_min_));
+        if (__s && __ibs_ >= sizeof(__extbuf_min_))
+        {
+            __intbuf_ = __s;
+            __owns_ib_ = false;
+        }
+        else
+        {
+            __intbuf_ = new char_type[__ibs_];
+            __owns_ib_ = true;
+        }
+    }
+    else
+    {
+        __ibs_ = 0;
+        __intbuf_ = nullptr;
+        __owns_ib_ = false;
+    }
+    return this;
+}
+
+template <class _CharT, class _Traits>
+typename basic_filebuf<_CharT, _Traits>::pos_type
+basic_filebuf<_CharT, _Traits>::seekoff(off_type __off, ios_base::seekdir __way,
+                                        ios_base::openmode)
+{
+    if (!__cv_)
+        __throw_bad_cast();
+
+    int __width = __cv_->encoding();
+    if (__file_ == nullptr || (__width <= 0 && __off != 0) || sync())
+        return pos_type(off_type(-1));
+    // __width > 0 || __off == 0
+    int __whence;
+    switch (__way)
+    {
+    case ios_base::beg:
+        __whence = SEEK_SET;
+        break;
+    case ios_base::cur:
+        __whence = SEEK_CUR;
+        break;
+    case ios_base::end:
+        __whence = SEEK_END;
+        break;
+    default:
+        return pos_type(off_type(-1));
+    }
 #if defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
-    if (fseek(__file_, __width > 0 ? __width * __off : 0, __whence)) 
-        return pos_type(off_type(-1)); 
-    pos_type __r = ftell(__file_); 
-#else 
-    if (fseeko(__file_, __width > 0 ? __width * __off : 0, __whence)) 
-        return pos_type(off_type(-1)); 
-    pos_type __r = ftello(__file_); 
-#endif 
-    __r.state(__st_); 
-    return __r; 
-} 
- 
-template <class _CharT, class _Traits> 
-typename basic_filebuf<_CharT, _Traits>::pos_type 
-basic_filebuf<_CharT, _Traits>::seekpos(pos_type __sp, ios_base::openmode) 
-{ 
-    if (__file_ == nullptr || sync()) 
-        return pos_type(off_type(-1)); 
+    if (fseek(__file_, __width > 0 ? __width * __off : 0, __whence))
+        return pos_type(off_type(-1));
+    pos_type __r = ftell(__file_);
+#else
+    if (fseeko(__file_, __width > 0 ? __width * __off : 0, __whence))
+        return pos_type(off_type(-1));
+    pos_type __r = ftello(__file_);
+#endif
+    __r.state(__st_);
+    return __r;
+}
+
+template <class _CharT, class _Traits>
+typename basic_filebuf<_CharT, _Traits>::pos_type
+basic_filebuf<_CharT, _Traits>::seekpos(pos_type __sp, ios_base::openmode)
+{
+    if (__file_ == nullptr || sync())
+        return pos_type(off_type(-1));
 #if defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
-    if (fseek(__file_, __sp, SEEK_SET)) 
-        return pos_type(off_type(-1)); 
-#else 
-    if (fseeko(__file_, __sp, SEEK_SET)) 
-        return pos_type(off_type(-1)); 
-#endif 
-    __st_ = __sp.state(); 
-    return __sp; 
-} 
- 
-template <class _CharT, class _Traits> 
-int 
-basic_filebuf<_CharT, _Traits>::sync() 
-{ 
-    if (__file_ == nullptr) 
-        return 0; 
-    if (!__cv_) 
-        __throw_bad_cast(); 
- 
-    if (__cm_ & ios_base::out) 
-    { 
-        if (this->pptr() != this->pbase()) 
-            if (overflow() == traits_type::eof()) 
-                return -1; 
-        codecvt_base::result __r; 
-        do 
-        { 
-            char* __extbe; 
-            __r = __cv_->unshift(__st_, __extbuf_, __extbuf_ + __ebs_, __extbe); 
-            size_t __nmemb = static_cast<size_t>(__extbe - __extbuf_); 
-            if (fwrite(__extbuf_, 1, __nmemb, __file_) != __nmemb) 
-                return -1; 
-        } while (__r == codecvt_base::partial); 
-        if (__r == codecvt_base::error) 
-            return -1; 
-        if (fflush(__file_)) 
-            return -1; 
-    } 
-    else if (__cm_ & ios_base::in) 
-    { 
-        off_type __c; 
-        state_type __state = __st_last_; 
-        bool __update_st = false; 
-        if (__always_noconv_) 
-            __c = this->egptr() - this->gptr(); 
-        else 
-        { 
-            int __width = __cv_->encoding(); 
-            __c = __extbufend_ - __extbufnext_; 
-            if (__width > 0) 
-                __c += __width * (this->egptr() - this->gptr()); 
-            else 
-            { 
-                if (this->gptr() != this->egptr()) 
-                { 
-                    const int __off =  __cv_->length(__state, __extbuf_, 
-                                                     __extbufnext_, 
-                                                     this->gptr() - this->eback()); 
-                    __c += __extbufnext_ - __extbuf_ - __off; 
-                    __update_st = true; 
-                } 
-            } 
-        } 
+    if (fseek(__file_, __sp, SEEK_SET))
+        return pos_type(off_type(-1));
+#else
+    if (fseeko(__file_, __sp, SEEK_SET))
+        return pos_type(off_type(-1));
+#endif
+    __st_ = __sp.state();
+    return __sp;
+}
+
+template <class _CharT, class _Traits>
+int
+basic_filebuf<_CharT, _Traits>::sync()
+{
+    if (__file_ == nullptr)
+        return 0;
+    if (!__cv_)
+        __throw_bad_cast();
+
+    if (__cm_ & ios_base::out)
+    {
+        if (this->pptr() != this->pbase())
+            if (overflow() == traits_type::eof())
+                return -1;
+        codecvt_base::result __r;
+        do
+        {
+            char* __extbe;
+            __r = __cv_->unshift(__st_, __extbuf_, __extbuf_ + __ebs_, __extbe);
+            size_t __nmemb = static_cast<size_t>(__extbe - __extbuf_);
+            if (fwrite(__extbuf_, 1, __nmemb, __file_) != __nmemb)
+                return -1;
+        } while (__r == codecvt_base::partial);
+        if (__r == codecvt_base::error)
+            return -1;
+        if (fflush(__file_))
+            return -1;
+    }
+    else if (__cm_ & ios_base::in)
+    {
+        off_type __c;
+        state_type __state = __st_last_;
+        bool __update_st = false;
+        if (__always_noconv_)
+            __c = this->egptr() - this->gptr();
+        else
+        {
+            int __width = __cv_->encoding();
+            __c = __extbufend_ - __extbufnext_;
+            if (__width > 0)
+                __c += __width * (this->egptr() - this->gptr());
+            else
+            {
+                if (this->gptr() != this->egptr())
+                {
+                    const int __off =  __cv_->length(__state, __extbuf_,
+                                                     __extbufnext_,
+                                                     this->gptr() - this->eback());
+                    __c += __extbufnext_ - __extbuf_ - __off;
+                    __update_st = true;
+                }
+            }
+        }
 #if defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
-        if (fseek(__file_, -__c, SEEK_CUR)) 
-            return -1; 
-#else 
-        if (fseeko(__file_, -__c, SEEK_CUR)) 
-            return -1; 
-#endif 
-        if (__update_st) 
-            __st_ = __state; 
-        __extbufnext_ = __extbufend_ = __extbuf_; 
-        this->setg(nullptr, nullptr, nullptr); 
-        __cm_ = 0; 
-    } 
-    return 0; 
-} 
- 
-template <class _CharT, class _Traits> 
-void 
-basic_filebuf<_CharT, _Traits>::imbue(const locale& __loc) 
-{ 
-    sync(); 
-    __cv_ = &use_facet<codecvt<char_type, char, state_type> >(__loc); 
-    bool __old_anc = __always_noconv_; 
-    __always_noconv_ = __cv_->always_noconv(); 
-    if (__old_anc != __always_noconv_) 
-    { 
-        this->setg(nullptr, nullptr, nullptr); 
-        this->setp(nullptr, nullptr); 
-        // invariant, char_type is char, else we couldn't get here 
-        if (__always_noconv_)  // need to dump __intbuf_ 
-        { 
-            if (__owns_eb_) 
-                delete [] __extbuf_; 
-            __owns_eb_ = __owns_ib_; 
-            __ebs_ = __ibs_; 
-            __extbuf_ = (char*)__intbuf_; 
-            __ibs_ = 0; 
-            __intbuf_ = nullptr; 
-            __owns_ib_ = false; 
-        } 
-        else  // need to obtain an __intbuf_. 
-        {     // If __extbuf_ is user-supplied, use it, else new __intbuf_ 
-            if (!__owns_eb_ && __extbuf_ != __extbuf_min_) 
-            { 
-                __ibs_ = __ebs_; 
-                __intbuf_ = (char_type*)__extbuf_; 
-                __owns_ib_ = false; 
-                __extbuf_ = new char[__ebs_]; 
-                __owns_eb_ = true; 
-            } 
-            else 
-            { 
-                __ibs_ = __ebs_; 
-                __intbuf_ = new char_type[__ibs_]; 
-                __owns_ib_ = true; 
-            } 
-        } 
-    } 
-} 
- 
-template <class _CharT, class _Traits> 
-bool 
-basic_filebuf<_CharT, _Traits>::__read_mode() 
-{ 
-    if (!(__cm_ & ios_base::in)) 
-    { 
-        this->setp(nullptr, nullptr); 
-        if (__always_noconv_) 
-            this->setg((char_type*)__extbuf_, 
-                       (char_type*)__extbuf_ + __ebs_, 
-                       (char_type*)__extbuf_ + __ebs_); 
-        else 
-            this->setg(__intbuf_, __intbuf_ + __ibs_, __intbuf_ + __ibs_); 
-        __cm_ = ios_base::in; 
-        return true; 
-    } 
-    return false; 
-} 
- 
-template <class _CharT, class _Traits> 
-void 
-basic_filebuf<_CharT, _Traits>::__write_mode() 
-{ 
-    if (!(__cm_ & ios_base::out)) 
-    { 
-        this->setg(nullptr, nullptr, nullptr); 
-        if (__ebs_ > sizeof(__extbuf_min_)) 
-        { 
-            if (__always_noconv_) 
-                this->setp((char_type*)__extbuf_, 
-                           (char_type*)__extbuf_ + (__ebs_ - 1)); 
-            else 
-                this->setp(__intbuf_, __intbuf_ + (__ibs_ - 1)); 
-        } 
-        else 
-            this->setp(nullptr, nullptr); 
-        __cm_ = ios_base::out; 
-    } 
-} 
- 
-// basic_ifstream 
- 
-template <class _CharT, class _Traits> 
-class _LIBCPP_TEMPLATE_VIS basic_ifstream 
-    : public basic_istream<_CharT, _Traits> 
-{ 
-public: 
-    typedef _CharT                         char_type; 
-    typedef _Traits                        traits_type; 
-    typedef typename traits_type::int_type int_type; 
-    typedef typename traits_type::pos_type pos_type; 
-    typedef typename traits_type::off_type off_type; 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_ifstream(); 
-    _LIBCPP_INLINE_VISIBILITY 
-    explicit basic_ifstream(const char* __s, ios_base::openmode __mode = ios_base::in); 
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR 
-    _LIBCPP_INLINE_VISIBILITY 
-    explicit basic_ifstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::in); 
-#endif 
-    _LIBCPP_INLINE_VISIBILITY 
-    explicit basic_ifstream(const string& __s, ios_base::openmode __mode = ios_base::in); 
-#if _LIBCPP_STD_VER >= 17 && !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY) 
-    _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_INLINE_VISIBILITY 
-    explicit basic_ifstream(const filesystem::path& __p, ios_base::openmode __mode = ios_base::in) 
-      : basic_ifstream(__p.c_str(), __mode) {} 
-#endif // _LIBCPP_STD_VER >= 17 
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_ifstream(basic_ifstream&& __rhs); 
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_ifstream& operator=(basic_ifstream&& __rhs); 
-    _LIBCPP_INLINE_VISIBILITY 
-    void swap(basic_ifstream& __rhs); 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_filebuf<char_type, traits_type>* rdbuf() const; 
-    _LIBCPP_INLINE_VISIBILITY 
-    bool is_open() const; 
-    void open(const char* __s, ios_base::openmode __mode = ios_base::in); 
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR 
-    void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::in); 
-#endif 
-    void open(const string& __s, ios_base::openmode __mode = ios_base::in); 
-#if _LIBCPP_STD_VER >= 17 && !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY) 
-    _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_INLINE_VISIBILITY 
-    void open(const filesystem::path& __p, 
-              ios_base::openmode __mode = ios_base::in) { 
-      return open(__p.c_str(), __mode); 
-    } 
-#endif // _LIBCPP_STD_VER >= 17 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    void __open(int __fd, ios_base::openmode __mode); 
-    _LIBCPP_INLINE_VISIBILITY 
-    void close(); 
- 
-private: 
-    basic_filebuf<char_type, traits_type> __sb_; 
-}; 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_ifstream<_CharT, _Traits>::basic_ifstream() 
-    : basic_istream<char_type, traits_type>(&__sb_) 
-{ 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_ifstream<_CharT, _Traits>::basic_ifstream(const char* __s, ios_base::openmode __mode) 
-    : basic_istream<char_type, traits_type>(&__sb_) 
-{ 
-    if (__sb_.open(__s, __mode | ios_base::in) == nullptr) 
-        this->setstate(ios_base::failbit); 
-} 
- 
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR 
-template <class _CharT, class _Traits> 
-inline 
-basic_ifstream<_CharT, _Traits>::basic_ifstream(const wchar_t* __s, ios_base::openmode __mode) 
-    : basic_istream<char_type, traits_type>(&__sb_) 
-{ 
-    if (__sb_.open(__s, __mode | ios_base::in) == nullptr) 
-        this->setstate(ios_base::failbit); 
-} 
-#endif 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_ifstream<_CharT, _Traits>::basic_ifstream(const string& __s, ios_base::openmode __mode) 
-    : basic_istream<char_type, traits_type>(&__sb_) 
-{ 
-    if (__sb_.open(__s, __mode | ios_base::in) == nullptr) 
-        this->setstate(ios_base::failbit); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_ifstream<_CharT, _Traits>::basic_ifstream(basic_ifstream&& __rhs) 
-    : basic_istream<char_type, traits_type>(_VSTD::move(__rhs)), 
-      __sb_(_VSTD::move(__rhs.__sb_)) 
-{ 
-    this->set_rdbuf(&__sb_); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_ifstream<_CharT, _Traits>& 
-basic_ifstream<_CharT, _Traits>::operator=(basic_ifstream&& __rhs) 
-{ 
-    basic_istream<char_type, traits_type>::operator=(_VSTD::move(__rhs)); 
-    __sb_ = _VSTD::move(__rhs.__sb_); 
-    return *this; 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-void 
-basic_ifstream<_CharT, _Traits>::swap(basic_ifstream& __rhs) 
-{ 
-    basic_istream<char_type, traits_type>::swap(__rhs); 
-    __sb_.swap(__rhs.__sb_); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline _LIBCPP_INLINE_VISIBILITY 
-void 
-swap(basic_ifstream<_CharT, _Traits>& __x, basic_ifstream<_CharT, _Traits>& __y) 
-{ 
-    __x.swap(__y); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_filebuf<_CharT, _Traits>* 
-basic_ifstream<_CharT, _Traits>::rdbuf() const 
-{ 
-    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-bool 
-basic_ifstream<_CharT, _Traits>::is_open() const 
-{ 
-    return __sb_.is_open(); 
-} 
- 
-template <class _CharT, class _Traits> 
-void 
-basic_ifstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode) 
-{ 
-    if (__sb_.open(__s, __mode | ios_base::in)) 
-        this->clear(); 
-    else 
-        this->setstate(ios_base::failbit); 
-} 
- 
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR 
-template <class _CharT, class _Traits> 
-void 
-basic_ifstream<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode) 
-{ 
-    if (__sb_.open(__s, __mode | ios_base::in)) 
-        this->clear(); 
-    else 
-        this->setstate(ios_base::failbit); 
-} 
-#endif 
- 
-template <class _CharT, class _Traits> 
-void 
-basic_ifstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode) 
-{ 
-    if (__sb_.open(__s, __mode | ios_base::in)) 
-        this->clear(); 
-    else 
-        this->setstate(ios_base::failbit); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-void basic_ifstream<_CharT, _Traits>::__open(int __fd, 
-                                             ios_base::openmode __mode) { 
-  if (__sb_.__open(__fd, __mode | ios_base::in)) 
-    this->clear(); 
-  else 
-    this->setstate(ios_base::failbit); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-void 
-basic_ifstream<_CharT, _Traits>::close() 
-{ 
-    if (__sb_.close() == 0) 
-        this->setstate(ios_base::failbit); 
-} 
- 
-// basic_ofstream 
- 
-template <class _CharT, class _Traits> 
-class _LIBCPP_TEMPLATE_VIS basic_ofstream 
-    : public basic_ostream<_CharT, _Traits> 
-{ 
-public: 
-    typedef _CharT                         char_type; 
-    typedef _Traits                        traits_type; 
-    typedef typename traits_type::int_type int_type; 
-    typedef typename traits_type::pos_type pos_type; 
-    typedef typename traits_type::off_type off_type; 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_ofstream(); 
-    _LIBCPP_INLINE_VISIBILITY 
-    explicit basic_ofstream(const char* __s, ios_base::openmode __mode = ios_base::out); 
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR 
-    _LIBCPP_INLINE_VISIBILITY 
-    explicit basic_ofstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::out); 
-#endif 
-    _LIBCPP_INLINE_VISIBILITY 
-    explicit basic_ofstream(const string& __s, ios_base::openmode __mode = ios_base::out); 
- 
-#if _LIBCPP_STD_VER >= 17 && !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY) 
-    _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_INLINE_VISIBILITY 
-    explicit basic_ofstream(const filesystem::path& __p, ios_base::openmode __mode = ios_base::out) 
-      : basic_ofstream(__p.c_str(), __mode) {} 
-#endif // _LIBCPP_STD_VER >= 17 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_ofstream(basic_ofstream&& __rhs); 
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_ofstream& operator=(basic_ofstream&& __rhs); 
-    _LIBCPP_INLINE_VISIBILITY 
-    void swap(basic_ofstream& __rhs); 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_filebuf<char_type, traits_type>* rdbuf() const; 
-    _LIBCPP_INLINE_VISIBILITY 
-    bool is_open() const; 
-    void open(const char* __s, ios_base::openmode __mode = ios_base::out); 
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR 
-    void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::out); 
-#endif 
-    void open(const string& __s, ios_base::openmode __mode = ios_base::out); 
- 
-#if _LIBCPP_STD_VER >= 17 && !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY) 
-    _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_INLINE_VISIBILITY 
-    void open(const filesystem::path& __p, ios_base::openmode __mode = ios_base::out) 
-    { return open(__p.c_str(), __mode); } 
-#endif // _LIBCPP_STD_VER >= 17 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    void __open(int __fd, ios_base::openmode __mode); 
-    _LIBCPP_INLINE_VISIBILITY 
-    void close(); 
- 
-private: 
-    basic_filebuf<char_type, traits_type> __sb_; 
-}; 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_ofstream<_CharT, _Traits>::basic_ofstream() 
-    : basic_ostream<char_type, traits_type>(&__sb_) 
-{ 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_ofstream<_CharT, _Traits>::basic_ofstream(const char* __s, ios_base::openmode __mode) 
-    : basic_ostream<char_type, traits_type>(&__sb_) 
-{ 
-    if (__sb_.open(__s, __mode | ios_base::out) == nullptr) 
-        this->setstate(ios_base::failbit); 
-} 
- 
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR 
-template <class _CharT, class _Traits> 
-inline 
-basic_ofstream<_CharT, _Traits>::basic_ofstream(const wchar_t* __s, ios_base::openmode __mode) 
-    : basic_ostream<char_type, traits_type>(&__sb_) 
-{ 
-    if (__sb_.open(__s, __mode | ios_base::out) == nullptr) 
-        this->setstate(ios_base::failbit); 
-} 
-#endif 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_ofstream<_CharT, _Traits>::basic_ofstream(const string& __s, ios_base::openmode __mode) 
-    : basic_ostream<char_type, traits_type>(&__sb_) 
-{ 
-    if (__sb_.open(__s, __mode | ios_base::out) == nullptr) 
-        this->setstate(ios_base::failbit); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_ofstream<_CharT, _Traits>::basic_ofstream(basic_ofstream&& __rhs) 
-    : basic_ostream<char_type, traits_type>(_VSTD::move(__rhs)), 
-      __sb_(_VSTD::move(__rhs.__sb_)) 
-{ 
-    this->set_rdbuf(&__sb_); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_ofstream<_CharT, _Traits>& 
-basic_ofstream<_CharT, _Traits>::operator=(basic_ofstream&& __rhs) 
-{ 
-    basic_ostream<char_type, traits_type>::operator=(_VSTD::move(__rhs)); 
-    __sb_ = _VSTD::move(__rhs.__sb_); 
-    return *this; 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-void 
-basic_ofstream<_CharT, _Traits>::swap(basic_ofstream& __rhs) 
-{ 
-    basic_ostream<char_type, traits_type>::swap(__rhs); 
-    __sb_.swap(__rhs.__sb_); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline _LIBCPP_INLINE_VISIBILITY 
-void 
-swap(basic_ofstream<_CharT, _Traits>& __x, basic_ofstream<_CharT, _Traits>& __y) 
-{ 
-    __x.swap(__y); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_filebuf<_CharT, _Traits>* 
-basic_ofstream<_CharT, _Traits>::rdbuf() const 
-{ 
-    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-bool 
-basic_ofstream<_CharT, _Traits>::is_open() const 
-{ 
-    return __sb_.is_open(); 
-} 
- 
-template <class _CharT, class _Traits> 
-void 
-basic_ofstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode) 
-{ 
-    if (__sb_.open(__s, __mode | ios_base::out)) 
-        this->clear(); 
-    else 
-        this->setstate(ios_base::failbit); 
-} 
- 
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR 
-template <class _CharT, class _Traits> 
-void 
-basic_ofstream<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode) 
-{ 
-    if (__sb_.open(__s, __mode | ios_base::out)) 
-        this->clear(); 
-    else 
-        this->setstate(ios_base::failbit); 
-} 
-#endif 
- 
-template <class _CharT, class _Traits> 
-void 
-basic_ofstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode) 
-{ 
-    if (__sb_.open(__s, __mode | ios_base::out)) 
-        this->clear(); 
-    else 
-        this->setstate(ios_base::failbit); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-void basic_ofstream<_CharT, _Traits>::__open(int __fd, 
-                                             ios_base::openmode __mode) { 
-  if (__sb_.__open(__fd, __mode | ios_base::out)) 
-    this->clear(); 
-  else 
-    this->setstate(ios_base::failbit); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-void 
-basic_ofstream<_CharT, _Traits>::close() 
-{ 
-    if (__sb_.close() == nullptr) 
-        this->setstate(ios_base::failbit); 
-} 
- 
-// basic_fstream 
- 
-template <class _CharT, class _Traits> 
-class _LIBCPP_TEMPLATE_VIS basic_fstream 
-    : public basic_iostream<_CharT, _Traits> 
-{ 
-public: 
-    typedef _CharT                         char_type; 
-    typedef _Traits                        traits_type; 
-    typedef typename traits_type::int_type int_type; 
-    typedef typename traits_type::pos_type pos_type; 
-    typedef typename traits_type::off_type off_type; 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_fstream(); 
-    _LIBCPP_INLINE_VISIBILITY 
-    explicit basic_fstream(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out); 
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR 
-    _LIBCPP_INLINE_VISIBILITY 
-    explicit basic_fstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::in | ios_base::out); 
-#endif 
-    _LIBCPP_INLINE_VISIBILITY 
-    explicit basic_fstream(const string& __s, ios_base::openmode __mode = ios_base::in | ios_base::out); 
- 
-#if _LIBCPP_STD_VER >= 17 && !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY) 
-    _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_INLINE_VISIBILITY 
-    explicit basic_fstream(const filesystem::path& __p, ios_base::openmode __mode = ios_base::in | ios_base::out) 
-      : basic_fstream(__p.c_str(), __mode) {} 
-#endif // _LIBCPP_STD_VER >= 17 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_fstream(basic_fstream&& __rhs); 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_fstream& operator=(basic_fstream&& __rhs); 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    void swap(basic_fstream& __rhs); 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_filebuf<char_type, traits_type>* rdbuf() const; 
-    _LIBCPP_INLINE_VISIBILITY 
-    bool is_open() const; 
-    void open(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out); 
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR 
-    void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::in | ios_base::out); 
-#endif 
-    void open(const string& __s, ios_base::openmode __mode = ios_base::in | ios_base::out); 
- 
-#if _LIBCPP_STD_VER >= 17 && !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY) 
-    _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_INLINE_VISIBILITY 
-    void open(const filesystem::path& __p, ios_base::openmode __mode = ios_base::in|ios_base::out) 
-    { return open(__p.c_str(), __mode); } 
-#endif // _LIBCPP_STD_VER >= 17 
- 
-    _LIBCPP_INLINE_VISIBILITY 
-    void close(); 
- 
-private: 
-    basic_filebuf<char_type, traits_type> __sb_; 
-}; 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_fstream<_CharT, _Traits>::basic_fstream() 
-    : basic_iostream<char_type, traits_type>(&__sb_) 
-{ 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_fstream<_CharT, _Traits>::basic_fstream(const char* __s, ios_base::openmode __mode) 
-    : basic_iostream<char_type, traits_type>(&__sb_) 
-{ 
-    if (__sb_.open(__s, __mode) == nullptr) 
-        this->setstate(ios_base::failbit); 
-} 
- 
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR 
-template <class _CharT, class _Traits> 
-inline 
-basic_fstream<_CharT, _Traits>::basic_fstream(const wchar_t* __s, ios_base::openmode __mode) 
-    : basic_iostream<char_type, traits_type>(&__sb_) 
-{ 
-    if (__sb_.open(__s, __mode) == nullptr) 
-        this->setstate(ios_base::failbit); 
-} 
-#endif 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_fstream<_CharT, _Traits>::basic_fstream(const string& __s, ios_base::openmode __mode) 
-    : basic_iostream<char_type, traits_type>(&__sb_) 
-{ 
-    if (__sb_.open(__s, __mode) == nullptr) 
-        this->setstate(ios_base::failbit); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_fstream<_CharT, _Traits>::basic_fstream(basic_fstream&& __rhs) 
-    : basic_iostream<char_type, traits_type>(_VSTD::move(__rhs)), 
-      __sb_(_VSTD::move(__rhs.__sb_)) 
-{ 
-    this->set_rdbuf(&__sb_); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_fstream<_CharT, _Traits>& 
-basic_fstream<_CharT, _Traits>::operator=(basic_fstream&& __rhs) 
-{ 
-    basic_iostream<char_type, traits_type>::operator=(_VSTD::move(__rhs)); 
-    __sb_ = _VSTD::move(__rhs.__sb_); 
-    return *this; 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-void 
-basic_fstream<_CharT, _Traits>::swap(basic_fstream& __rhs) 
-{ 
-    basic_iostream<char_type, traits_type>::swap(__rhs); 
-    __sb_.swap(__rhs.__sb_); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline _LIBCPP_INLINE_VISIBILITY 
-void 
-swap(basic_fstream<_CharT, _Traits>& __x, basic_fstream<_CharT, _Traits>& __y) 
-{ 
-    __x.swap(__y); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-basic_filebuf<_CharT, _Traits>* 
-basic_fstream<_CharT, _Traits>::rdbuf() const 
-{ 
-    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-bool 
-basic_fstream<_CharT, _Traits>::is_open() const 
-{ 
-    return __sb_.is_open(); 
-} 
- 
-template <class _CharT, class _Traits> 
-void 
-basic_fstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode) 
-{ 
-    if (__sb_.open(__s, __mode)) 
-        this->clear(); 
-    else 
-        this->setstate(ios_base::failbit); 
-} 
- 
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR 
-template <class _CharT, class _Traits> 
-void 
-basic_fstream<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode) 
-{ 
-    if (__sb_.open(__s, __mode)) 
-        this->clear(); 
-    else 
-        this->setstate(ios_base::failbit); 
-} 
-#endif 
- 
-template <class _CharT, class _Traits> 
-void 
-basic_fstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode) 
-{ 
-    if (__sb_.open(__s, __mode)) 
-        this->clear(); 
-    else 
-        this->setstate(ios_base::failbit); 
-} 
- 
-template <class _CharT, class _Traits> 
-inline 
-void 
-basic_fstream<_CharT, _Traits>::close() 
-{ 
-    if (__sb_.close() == nullptr) 
-        this->setstate(ios_base::failbit); 
-} 
- 
-#if defined(_LIBCPP_ABI_ENABLE_ADDITIONAL_IOSTREAM_EXPLICIT_INSTANTIATIONS_1) 
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_ifstream<char>) 
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_ofstream<char>) 
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_filebuf<char>) 
-#endif 
- 
-_LIBCPP_END_NAMESPACE_STD 
- 
-_LIBCPP_POP_MACROS 
- 
-#endif // _LIBCPP_FSTREAM 
+        if (fseek(__file_, -__c, SEEK_CUR))
+            return -1;
+#else
+        if (fseeko(__file_, -__c, SEEK_CUR))
+            return -1;
+#endif
+        if (__update_st)
+            __st_ = __state;
+        __extbufnext_ = __extbufend_ = __extbuf_;
+        this->setg(nullptr, nullptr, nullptr);
+        __cm_ = 0;
+    }
+    return 0;
+}
+
+template <class _CharT, class _Traits>
+void
+basic_filebuf<_CharT, _Traits>::imbue(const locale& __loc)
+{
+    sync();
+    __cv_ = &use_facet<codecvt<char_type, char, state_type> >(__loc);
+    bool __old_anc = __always_noconv_;
+    __always_noconv_ = __cv_->always_noconv();
+    if (__old_anc != __always_noconv_)
+    {
+        this->setg(nullptr, nullptr, nullptr);
+        this->setp(nullptr, nullptr);
+        // invariant, char_type is char, else we couldn't get here
+        if (__always_noconv_)  // need to dump __intbuf_
+        {
+            if (__owns_eb_)
+                delete [] __extbuf_;
+            __owns_eb_ = __owns_ib_;
+            __ebs_ = __ibs_;
+            __extbuf_ = (char*)__intbuf_;
+            __ibs_ = 0;
+            __intbuf_ = nullptr;
+            __owns_ib_ = false;
+        }
+        else  // need to obtain an __intbuf_.
+        {     // If __extbuf_ is user-supplied, use it, else new __intbuf_
+            if (!__owns_eb_ && __extbuf_ != __extbuf_min_)
+            {
+                __ibs_ = __ebs_;
+                __intbuf_ = (char_type*)__extbuf_;
+                __owns_ib_ = false;
+                __extbuf_ = new char[__ebs_];
+                __owns_eb_ = true;
+            }
+            else
+            {
+                __ibs_ = __ebs_;
+                __intbuf_ = new char_type[__ibs_];
+                __owns_ib_ = true;
+            }
+        }
+    }
+}
+
+template <class _CharT, class _Traits>
+bool
+basic_filebuf<_CharT, _Traits>::__read_mode()
+{
+    if (!(__cm_ & ios_base::in))
+    {
+        this->setp(nullptr, nullptr);
+        if (__always_noconv_)
+            this->setg((char_type*)__extbuf_,
+                       (char_type*)__extbuf_ + __ebs_,
+                       (char_type*)__extbuf_ + __ebs_);
+        else
+            this->setg(__intbuf_, __intbuf_ + __ibs_, __intbuf_ + __ibs_);
+        __cm_ = ios_base::in;
+        return true;
+    }
+    return false;
+}
+
+template <class _CharT, class _Traits>
+void
+basic_filebuf<_CharT, _Traits>::__write_mode()
+{
+    if (!(__cm_ & ios_base::out))
+    {
+        this->setg(nullptr, nullptr, nullptr);
+        if (__ebs_ > sizeof(__extbuf_min_))
+        {
+            if (__always_noconv_)
+                this->setp((char_type*)__extbuf_,
+                           (char_type*)__extbuf_ + (__ebs_ - 1));
+            else
+                this->setp(__intbuf_, __intbuf_ + (__ibs_ - 1));
+        }
+        else
+            this->setp(nullptr, nullptr);
+        __cm_ = ios_base::out;
+    }
+}
+
+// basic_ifstream
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TEMPLATE_VIS basic_ifstream
+    : public basic_istream<_CharT, _Traits>
+{
+public:
+    typedef _CharT                         char_type;
+    typedef _Traits                        traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    _LIBCPP_INLINE_VISIBILITY
+    basic_ifstream();
+    _LIBCPP_INLINE_VISIBILITY
+    explicit basic_ifstream(const char* __s, ios_base::openmode __mode = ios_base::in);
+#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
+    _LIBCPP_INLINE_VISIBILITY
+    explicit basic_ifstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::in);
+#endif
+    _LIBCPP_INLINE_VISIBILITY
+    explicit basic_ifstream(const string& __s, ios_base::openmode __mode = ios_base::in);
+#if _LIBCPP_STD_VER >= 17 && !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY)
+    _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_INLINE_VISIBILITY
+    explicit basic_ifstream(const filesystem::path& __p, ios_base::openmode __mode = ios_base::in)
+      : basic_ifstream(__p.c_str(), __mode) {}
+#endif // _LIBCPP_STD_VER >= 17
+    _LIBCPP_INLINE_VISIBILITY
+    basic_ifstream(basic_ifstream&& __rhs);
+    _LIBCPP_INLINE_VISIBILITY
+    basic_ifstream& operator=(basic_ifstream&& __rhs);
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(basic_ifstream& __rhs);
+
+    _LIBCPP_INLINE_VISIBILITY
+    basic_filebuf<char_type, traits_type>* rdbuf() const;
+    _LIBCPP_INLINE_VISIBILITY
+    bool is_open() const;
+    void open(const char* __s, ios_base::openmode __mode = ios_base::in);
+#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
+    void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::in);
+#endif
+    void open(const string& __s, ios_base::openmode __mode = ios_base::in);
+#if _LIBCPP_STD_VER >= 17 && !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY)
+    _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_INLINE_VISIBILITY
+    void open(const filesystem::path& __p,
+              ios_base::openmode __mode = ios_base::in) {
+      return open(__p.c_str(), __mode);
+    }
+#endif // _LIBCPP_STD_VER >= 17
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __open(int __fd, ios_base::openmode __mode);
+    _LIBCPP_INLINE_VISIBILITY
+    void close();
+
+private:
+    basic_filebuf<char_type, traits_type> __sb_;
+};
+
+template <class _CharT, class _Traits>
+inline
+basic_ifstream<_CharT, _Traits>::basic_ifstream()
+    : basic_istream<char_type, traits_type>(&__sb_)
+{
+}
+
+template <class _CharT, class _Traits>
+inline
+basic_ifstream<_CharT, _Traits>::basic_ifstream(const char* __s, ios_base::openmode __mode)
+    : basic_istream<char_type, traits_type>(&__sb_)
+{
+    if (__sb_.open(__s, __mode | ios_base::in) == nullptr)
+        this->setstate(ios_base::failbit);
+}
+
+#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
+template <class _CharT, class _Traits>
+inline
+basic_ifstream<_CharT, _Traits>::basic_ifstream(const wchar_t* __s, ios_base::openmode __mode)
+    : basic_istream<char_type, traits_type>(&__sb_)
+{
+    if (__sb_.open(__s, __mode | ios_base::in) == nullptr)
+        this->setstate(ios_base::failbit);
+}
+#endif
+
+template <class _CharT, class _Traits>
+inline
+basic_ifstream<_CharT, _Traits>::basic_ifstream(const string& __s, ios_base::openmode __mode)
+    : basic_istream<char_type, traits_type>(&__sb_)
+{
+    if (__sb_.open(__s, __mode | ios_base::in) == nullptr)
+        this->setstate(ios_base::failbit);
+}
+
+template <class _CharT, class _Traits>
+inline
+basic_ifstream<_CharT, _Traits>::basic_ifstream(basic_ifstream&& __rhs)
+    : basic_istream<char_type, traits_type>(_VSTD::move(__rhs)),
+      __sb_(_VSTD::move(__rhs.__sb_))
+{
+    this->set_rdbuf(&__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline
+basic_ifstream<_CharT, _Traits>&
+basic_ifstream<_CharT, _Traits>::operator=(basic_ifstream&& __rhs)
+{
+    basic_istream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
+    __sb_ = _VSTD::move(__rhs.__sb_);
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+inline
+void
+basic_ifstream<_CharT, _Traits>::swap(basic_ifstream& __rhs)
+{
+    basic_istream<char_type, traits_type>::swap(__rhs);
+    __sb_.swap(__rhs.__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(basic_ifstream<_CharT, _Traits>& __x, basic_ifstream<_CharT, _Traits>& __y)
+{
+    __x.swap(__y);
+}
+
+template <class _CharT, class _Traits>
+inline
+basic_filebuf<_CharT, _Traits>*
+basic_ifstream<_CharT, _Traits>::rdbuf() const
+{
+    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline
+bool
+basic_ifstream<_CharT, _Traits>::is_open() const
+{
+    return __sb_.is_open();
+}
+
+template <class _CharT, class _Traits>
+void
+basic_ifstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
+{
+    if (__sb_.open(__s, __mode | ios_base::in))
+        this->clear();
+    else
+        this->setstate(ios_base::failbit);
+}
+
+#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
+template <class _CharT, class _Traits>
+void
+basic_ifstream<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode)
+{
+    if (__sb_.open(__s, __mode | ios_base::in))
+        this->clear();
+    else
+        this->setstate(ios_base::failbit);
+}
+#endif
+
+template <class _CharT, class _Traits>
+void
+basic_ifstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
+{
+    if (__sb_.open(__s, __mode | ios_base::in))
+        this->clear();
+    else
+        this->setstate(ios_base::failbit);
+}
+
+template <class _CharT, class _Traits>
+inline
+void basic_ifstream<_CharT, _Traits>::__open(int __fd,
+                                             ios_base::openmode __mode) {
+  if (__sb_.__open(__fd, __mode | ios_base::in))
+    this->clear();
+  else
+    this->setstate(ios_base::failbit);
+}
+
+template <class _CharT, class _Traits>
+inline
+void
+basic_ifstream<_CharT, _Traits>::close()
+{
+    if (__sb_.close() == 0)
+        this->setstate(ios_base::failbit);
+}
+
+// basic_ofstream
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TEMPLATE_VIS basic_ofstream
+    : public basic_ostream<_CharT, _Traits>
+{
+public:
+    typedef _CharT                         char_type;
+    typedef _Traits                        traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    _LIBCPP_INLINE_VISIBILITY
+    basic_ofstream();
+    _LIBCPP_INLINE_VISIBILITY
+    explicit basic_ofstream(const char* __s, ios_base::openmode __mode = ios_base::out);
+#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
+    _LIBCPP_INLINE_VISIBILITY
+    explicit basic_ofstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::out);
+#endif
+    _LIBCPP_INLINE_VISIBILITY
+    explicit basic_ofstream(const string& __s, ios_base::openmode __mode = ios_base::out);
+
+#if _LIBCPP_STD_VER >= 17 && !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY)
+    _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_INLINE_VISIBILITY
+    explicit basic_ofstream(const filesystem::path& __p, ios_base::openmode __mode = ios_base::out)
+      : basic_ofstream(__p.c_str(), __mode) {}
+#endif // _LIBCPP_STD_VER >= 17
+
+    _LIBCPP_INLINE_VISIBILITY
+    basic_ofstream(basic_ofstream&& __rhs);
+    _LIBCPP_INLINE_VISIBILITY
+    basic_ofstream& operator=(basic_ofstream&& __rhs);
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(basic_ofstream& __rhs);
+
+    _LIBCPP_INLINE_VISIBILITY
+    basic_filebuf<char_type, traits_type>* rdbuf() const;
+    _LIBCPP_INLINE_VISIBILITY
+    bool is_open() const;
+    void open(const char* __s, ios_base::openmode __mode = ios_base::out);
+#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
+    void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::out);
+#endif
+    void open(const string& __s, ios_base::openmode __mode = ios_base::out);
+
+#if _LIBCPP_STD_VER >= 17 && !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY)
+    _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_INLINE_VISIBILITY
+    void open(const filesystem::path& __p, ios_base::openmode __mode = ios_base::out)
+    { return open(__p.c_str(), __mode); }
+#endif // _LIBCPP_STD_VER >= 17
+
+    _LIBCPP_INLINE_VISIBILITY
+    void __open(int __fd, ios_base::openmode __mode);
+    _LIBCPP_INLINE_VISIBILITY
+    void close();
+
+private:
+    basic_filebuf<char_type, traits_type> __sb_;
+};
+
+template <class _CharT, class _Traits>
+inline
+basic_ofstream<_CharT, _Traits>::basic_ofstream()
+    : basic_ostream<char_type, traits_type>(&__sb_)
+{
+}
+
+template <class _CharT, class _Traits>
+inline
+basic_ofstream<_CharT, _Traits>::basic_ofstream(const char* __s, ios_base::openmode __mode)
+    : basic_ostream<char_type, traits_type>(&__sb_)
+{
+    if (__sb_.open(__s, __mode | ios_base::out) == nullptr)
+        this->setstate(ios_base::failbit);
+}
+
+#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
+template <class _CharT, class _Traits>
+inline
+basic_ofstream<_CharT, _Traits>::basic_ofstream(const wchar_t* __s, ios_base::openmode __mode)
+    : basic_ostream<char_type, traits_type>(&__sb_)
+{
+    if (__sb_.open(__s, __mode | ios_base::out) == nullptr)
+        this->setstate(ios_base::failbit);
+}
+#endif
+
+template <class _CharT, class _Traits>
+inline
+basic_ofstream<_CharT, _Traits>::basic_ofstream(const string& __s, ios_base::openmode __mode)
+    : basic_ostream<char_type, traits_type>(&__sb_)
+{
+    if (__sb_.open(__s, __mode | ios_base::out) == nullptr)
+        this->setstate(ios_base::failbit);
+}
+
+template <class _CharT, class _Traits>
+inline
+basic_ofstream<_CharT, _Traits>::basic_ofstream(basic_ofstream&& __rhs)
+    : basic_ostream<char_type, traits_type>(_VSTD::move(__rhs)),
+      __sb_(_VSTD::move(__rhs.__sb_))
+{
+    this->set_rdbuf(&__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline
+basic_ofstream<_CharT, _Traits>&
+basic_ofstream<_CharT, _Traits>::operator=(basic_ofstream&& __rhs)
+{
+    basic_ostream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
+    __sb_ = _VSTD::move(__rhs.__sb_);
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+inline
+void
+basic_ofstream<_CharT, _Traits>::swap(basic_ofstream& __rhs)
+{
+    basic_ostream<char_type, traits_type>::swap(__rhs);
+    __sb_.swap(__rhs.__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(basic_ofstream<_CharT, _Traits>& __x, basic_ofstream<_CharT, _Traits>& __y)
+{
+    __x.swap(__y);
+}
+
+template <class _CharT, class _Traits>
+inline
+basic_filebuf<_CharT, _Traits>*
+basic_ofstream<_CharT, _Traits>::rdbuf() const
+{
+    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline
+bool
+basic_ofstream<_CharT, _Traits>::is_open() const
+{
+    return __sb_.is_open();
+}
+
+template <class _CharT, class _Traits>
+void
+basic_ofstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
+{
+    if (__sb_.open(__s, __mode | ios_base::out))
+        this->clear();
+    else
+        this->setstate(ios_base::failbit);
+}
+
+#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
+template <class _CharT, class _Traits>
+void
+basic_ofstream<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode)
+{
+    if (__sb_.open(__s, __mode | ios_base::out))
+        this->clear();
+    else
+        this->setstate(ios_base::failbit);
+}
+#endif
+
+template <class _CharT, class _Traits>
+void
+basic_ofstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
+{
+    if (__sb_.open(__s, __mode | ios_base::out))
+        this->clear();
+    else
+        this->setstate(ios_base::failbit);
+}
+
+template <class _CharT, class _Traits>
+inline
+void basic_ofstream<_CharT, _Traits>::__open(int __fd,
+                                             ios_base::openmode __mode) {
+  if (__sb_.__open(__fd, __mode | ios_base::out))
+    this->clear();
+  else
+    this->setstate(ios_base::failbit);
+}
+
+template <class _CharT, class _Traits>
+inline
+void
+basic_ofstream<_CharT, _Traits>::close()
+{
+    if (__sb_.close() == nullptr)
+        this->setstate(ios_base::failbit);
+}
+
+// basic_fstream
+
+template <class _CharT, class _Traits>
+class _LIBCPP_TEMPLATE_VIS basic_fstream
+    : public basic_iostream<_CharT, _Traits>
+{
+public:
+    typedef _CharT                         char_type;
+    typedef _Traits                        traits_type;
+    typedef typename traits_type::int_type int_type;
+    typedef typename traits_type::pos_type pos_type;
+    typedef typename traits_type::off_type off_type;
+
+    _LIBCPP_INLINE_VISIBILITY
+    basic_fstream();
+    _LIBCPP_INLINE_VISIBILITY
+    explicit basic_fstream(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
+#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
+    _LIBCPP_INLINE_VISIBILITY
+    explicit basic_fstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
+#endif
+    _LIBCPP_INLINE_VISIBILITY
+    explicit basic_fstream(const string& __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
+
+#if _LIBCPP_STD_VER >= 17 && !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY)
+    _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_INLINE_VISIBILITY
+    explicit basic_fstream(const filesystem::path& __p, ios_base::openmode __mode = ios_base::in | ios_base::out)
+      : basic_fstream(__p.c_str(), __mode) {}
+#endif // _LIBCPP_STD_VER >= 17
+
+    _LIBCPP_INLINE_VISIBILITY
+    basic_fstream(basic_fstream&& __rhs);
+
+    _LIBCPP_INLINE_VISIBILITY
+    basic_fstream& operator=(basic_fstream&& __rhs);
+
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(basic_fstream& __rhs);
+
+    _LIBCPP_INLINE_VISIBILITY
+    basic_filebuf<char_type, traits_type>* rdbuf() const;
+    _LIBCPP_INLINE_VISIBILITY
+    bool is_open() const;
+    void open(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
+#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
+    void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
+#endif
+    void open(const string& __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
+
+#if _LIBCPP_STD_VER >= 17 && !defined(_LIBCPP_HAS_NO_FILESYSTEM_LIBRARY)
+    _LIBCPP_AVAILABILITY_FILESYSTEM _LIBCPP_INLINE_VISIBILITY
+    void open(const filesystem::path& __p, ios_base::openmode __mode = ios_base::in|ios_base::out)
+    { return open(__p.c_str(), __mode); }
+#endif // _LIBCPP_STD_VER >= 17
+
+    _LIBCPP_INLINE_VISIBILITY
+    void close();
+
+private:
+    basic_filebuf<char_type, traits_type> __sb_;
+};
+
+template <class _CharT, class _Traits>
+inline
+basic_fstream<_CharT, _Traits>::basic_fstream()
+    : basic_iostream<char_type, traits_type>(&__sb_)
+{
+}
+
+template <class _CharT, class _Traits>
+inline
+basic_fstream<_CharT, _Traits>::basic_fstream(const char* __s, ios_base::openmode __mode)
+    : basic_iostream<char_type, traits_type>(&__sb_)
+{
+    if (__sb_.open(__s, __mode) == nullptr)
+        this->setstate(ios_base::failbit);
+}
+
+#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
+template <class _CharT, class _Traits>
+inline
+basic_fstream<_CharT, _Traits>::basic_fstream(const wchar_t* __s, ios_base::openmode __mode)
+    : basic_iostream<char_type, traits_type>(&__sb_)
+{
+    if (__sb_.open(__s, __mode) == nullptr)
+        this->setstate(ios_base::failbit);
+}
+#endif
+
+template <class _CharT, class _Traits>
+inline
+basic_fstream<_CharT, _Traits>::basic_fstream(const string& __s, ios_base::openmode __mode)
+    : basic_iostream<char_type, traits_type>(&__sb_)
+{
+    if (__sb_.open(__s, __mode) == nullptr)
+        this->setstate(ios_base::failbit);
+}
+
+template <class _CharT, class _Traits>
+inline
+basic_fstream<_CharT, _Traits>::basic_fstream(basic_fstream&& __rhs)
+    : basic_iostream<char_type, traits_type>(_VSTD::move(__rhs)),
+      __sb_(_VSTD::move(__rhs.__sb_))
+{
+    this->set_rdbuf(&__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline
+basic_fstream<_CharT, _Traits>&
+basic_fstream<_CharT, _Traits>::operator=(basic_fstream&& __rhs)
+{
+    basic_iostream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
+    __sb_ = _VSTD::move(__rhs.__sb_);
+    return *this;
+}
+
+template <class _CharT, class _Traits>
+inline
+void
+basic_fstream<_CharT, _Traits>::swap(basic_fstream& __rhs)
+{
+    basic_iostream<char_type, traits_type>::swap(__rhs);
+    __sb_.swap(__rhs.__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(basic_fstream<_CharT, _Traits>& __x, basic_fstream<_CharT, _Traits>& __y)
+{
+    __x.swap(__y);
+}
+
+template <class _CharT, class _Traits>
+inline
+basic_filebuf<_CharT, _Traits>*
+basic_fstream<_CharT, _Traits>::rdbuf() const
+{
+    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
+}
+
+template <class _CharT, class _Traits>
+inline
+bool
+basic_fstream<_CharT, _Traits>::is_open() const
+{
+    return __sb_.is_open();
+}
+
+template <class _CharT, class _Traits>
+void
+basic_fstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
+{
+    if (__sb_.open(__s, __mode))
+        this->clear();
+    else
+        this->setstate(ios_base::failbit);
+}
+
+#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
+template <class _CharT, class _Traits>
+void
+basic_fstream<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode)
+{
+    if (__sb_.open(__s, __mode))
+        this->clear();
+    else
+        this->setstate(ios_base::failbit);
+}
+#endif
+
+template <class _CharT, class _Traits>
+void
+basic_fstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
+{
+    if (__sb_.open(__s, __mode))
+        this->clear();
+    else
+        this->setstate(ios_base::failbit);
+}
+
+template <class _CharT, class _Traits>
+inline
+void
+basic_fstream<_CharT, _Traits>::close()
+{
+    if (__sb_.close() == nullptr)
+        this->setstate(ios_base::failbit);
+}
+
+#if defined(_LIBCPP_ABI_ENABLE_ADDITIONAL_IOSTREAM_EXPLICIT_INSTANTIATIONS_1)
+_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_ifstream<char>)
+_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_ofstream<char>)
+_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_filebuf<char>)
+#endif
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP_FSTREAM