// File based streams -*- C++ -*- // Copyright (C) 1997-2020 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // Under Section 7 of GPL version 3, you are granted additional // permissions described in the GCC Runtime Library Exception, version // 3.1, as published by the Free Software Foundation. // You should have received a copy of the GNU General Public License and // a copy of the GCC Runtime Library Exception along with this program; // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see // <http://www.gnu.org/licenses/>. /** @file include/fstream * This is a Standard C++ Library header. */ // // ISO C++ 14882: 27.8 File-based streams // #ifndef _GLIBCXX_FSTREAM #define _GLIBCXX_FSTREAM 1 #pragma GCC system_header #include <istream> #include <ostream> #include <bits/codecvt.h> #include <cstdio> // For BUFSIZ #include <bits/basic_file.h> // For __basic_file, __c_lock #if __cplusplus >= 201103L #include <string> // For std::string overloads. #endif namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION #if __cplusplus >= 201703L // Enable if _Path is a filesystem::path or experimental::filesystem::path template<typename _Path, typename _Result = _Path, typename _Path2 = decltype(std::declval<_Path&>().make_preferred().filename())> using _If_fs_path = enable_if_t<is_same_v<_Path, _Path2>, _Result>; #endif // C++17 // [27.8.1.1] template class basic_filebuf /** * @brief The actual work of input and output (for files). * @ingroup io * * @tparam _CharT Type of character stream. * @tparam _Traits Traits for character type, defaults to * char_traits<_CharT>. * * This class associates both its input and output sequence with an * external disk file, and maintains a joint file position for both * sequences. Many of its semantics are described in terms of similar * behavior in the Standard C Library's @c FILE streams. * * Requirements on traits_type, specific to this class: * - traits_type::pos_type must be fpos<traits_type::state_type> * - traits_type::off_type must be streamoff * - traits_type::state_type must be Assignable and DefaultConstructible, * - traits_type::state_type() must be the initial state for codecvt. */ template<typename _CharT, typename _Traits> class basic_filebuf : public basic_streambuf<_CharT, _Traits> { #if __cplusplus >= 201103L template<typename _Tp> using __chk_state = __and_<is_copy_assignable<_Tp>, is_copy_constructible<_Tp>, is_default_constructible<_Tp>>; static_assert(__chk_state<typename _Traits::state_type>::value, "state_type must be CopyAssignable, CopyConstructible" " and DefaultConstructible"); static_assert(is_same<typename _Traits::pos_type, fpos<typename _Traits::state_type>>::value, "pos_type must be fpos<state_type>"); #endif public: // Types: 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 basic_streambuf<char_type, traits_type> __streambuf_type; typedef basic_filebuf<char_type, traits_type> __filebuf_type; typedef __basic_file<char> __file_type; typedef typename traits_type::state_type __state_type; typedef codecvt<char_type, char, __state_type> __codecvt_type; friend class ios_base; // For sync_with_stdio. protected: // Data Members: // MT lock inherited from libio or other low-level io library. __c_lock _M_lock; // External buffer. __file_type _M_file; /// Place to stash in || out || in | out settings for current filebuf. ios_base::openmode _M_mode; // Beginning state type for codecvt. __state_type _M_state_beg; // During output, the state that corresponds to pptr(), // during input, the state that corresponds to egptr() and // _M_ext_next. __state_type _M_state_cur; // Not used for output. During input, the state that corresponds // to eback() and _M_ext_buf. __state_type _M_state_last; /// Pointer to the beginning of internal buffer. char_type* _M_buf; /** * Actual size of internal buffer. This number is equal to the size * of the put area + 1 position, reserved for the overflow char of * a full area. */ size_t _M_buf_size; // Set iff _M_buf is allocated memory from _M_allocate_internal_buffer. bool _M_buf_allocated; /** * _M_reading == false && _M_writing == false for @b uncommitted mode; * _M_reading == true for @b read mode; * _M_writing == true for @b write mode; * * NB: _M_reading == true && _M_writing == true is unused. */ bool _M_reading; bool _M_writing; //@{ /** * Necessary bits for putback buffer management. * * @note pbacks of over one character are not currently supported. */ char_type _M_pback; char_type* _M_pback_cur_save; char_type* _M_pback_end_save; bool _M_pback_init; //@} // Cached codecvt facet. const __codecvt_type* _M_codecvt; /** * Buffer for external characters. Used for input when * codecvt::always_noconv() == false. When valid, this corresponds * to eback(). */ char* _M_ext_buf; /** * Size of buffer held by _M_ext_buf. */ streamsize _M_ext_buf_size; /** * Pointers into the buffer held by _M_ext_buf that delimit a * subsequence of bytes that have been read but not yet converted. * When valid, _M_ext_next corresponds to egptr(). */ const char* _M_ext_next; char* _M_ext_end; /** * Initializes pback buffers, and moves normal buffers to safety. * Assumptions: * _M_in_cur has already been moved back */ void _M_create_pback() { if (!_M_pback_init) { _M_pback_cur_save = this->gptr(); _M_pback_end_save = this->egptr(); this->setg(&_M_pback, &_M_pback, &_M_pback + 1); _M_pback_init = true; } } /** * Deactivates pback buffer contents, and restores normal buffer. * Assumptions: * The pback buffer has only moved forward. */ void _M_destroy_pback() throw() { if (_M_pback_init) { // Length _M_in_cur moved in the pback buffer. _M_pback_cur_save += this->gptr() != this->eback(); this->setg(_M_buf, _M_pback_cur_save, _M_pback_end_save); _M_pback_init = false; } } public: // Constructors/destructor: /** * @brief Does not open any files. * * The default constructor initializes the parent class using its * own default ctor. */ basic_filebuf(); #if __cplusplus >= 201103L basic_filebuf(const basic_filebuf&) = delete; basic_filebuf(basic_filebuf&&); #endif /** * @brief The destructor closes the file first. */ virtual ~basic_filebuf() { __try { this->close(); } __catch(...) { } } #if __cplusplus >= 201103L basic_filebuf& operator=(const basic_filebuf&) = delete; basic_filebuf& operator=(basic_filebuf&&); void swap(basic_filebuf&); #endif // Members: /** * @brief Returns true if the external file is open. */ bool is_open() const throw() { return _M_file.is_open(); } /** * @brief Opens an external file. * @param __s The name of the file. * @param __mode The open mode flags. * @return @c this on success, NULL on failure * * If a file is already open, this function immediately fails. * Otherwise it tries to open the file named @a __s using the flags * given in @a __mode. * * Table 92, adapted here, gives the relation between openmode * combinations and the equivalent @c fopen() flags. * (NB: lines app, in|out|app, in|app, binary|app, binary|in|out|app, * and binary|in|app per DR 596) * <pre> * +---------------------------------------------------------+ * | ios_base Flag combination stdio equivalent | * |binary in out trunc app | * +---------------------------------------------------------+ * | + w | * | + + a | * | + a | * | + + w | * | + r | * | + + r+ | * | + + + w+ | * | + + + a+ | * | + + a+ | * +---------------------------------------------------------+ * | + + wb | * | + + + ab | * | + + ab | * | + + + wb | * | + + rb | * | + + + r+b | * | + + + + w+b | * | + + + + a+b | * | + + + a+b | * +---------------------------------------------------------+ * </pre> */ __filebuf_type* open(const char* __s, ios_base::openmode __mode); #if _GLIBCXX_HAVE__WFOPEN && _GLIBCXX_USE_WCHAR_T /** * @brief Opens an external file. * @param __s The name of the file, as a wide character string. * @param __mode The open mode flags. * @return @c this on success, NULL on failure */ __filebuf_type* open(const wchar_t* __s, ios_base::openmode __mode); #endif #if __cplusplus >= 201103L /** * @brief Opens an external file. * @param __s The name of the file. * @param __mode The open mode flags. * @return @c this on success, NULL on failure */ __filebuf_type* open(const std::string& __s, ios_base::openmode __mode) { return open(__s.c_str(), __mode); } #if __cplusplus >= 201703L /** * @brief Opens an external file. * @param __s The name of the file, as a filesystem::path. * @param __mode The open mode flags. * @return @c this on success, NULL on failure */ template<typename _Path> _If_fs_path<_Path, __filebuf_type*> open(const _Path& __s, ios_base::openmode __mode) { return open(__s.c_str(), __mode); } #endif // C++17 #endif // C++11 /** * @brief Closes the currently associated file. * @return @c this on success, NULL on failure * * If no file is currently open, this function immediately fails. * * If a <em>put buffer area</em> exists, @c overflow(eof) is * called to flush all the characters. The file is then * closed. * * If any operations fail, this function also fails. */ __filebuf_type* close(); protected: void _M_allocate_internal_buffer(); void _M_destroy_internal_buffer() throw(); // [27.8.1.4] overridden virtual functions virtual streamsize showmanyc(); // Stroustrup, 1998, p. 628 // underflow() and uflow() functions are called to get the next // character from the real input source when the buffer is empty. // Buffered input uses underflow() virtual int_type underflow(); virtual int_type pbackfail(int_type __c = _Traits::eof()); // Stroustrup, 1998, p 648 // The overflow() function is called to transfer characters to the // real output destination when the buffer is full. A call to // overflow(c) outputs the contents of the buffer plus the // character c. // 27.5.2.4.5 // Consume some sequence of the characters in the pending sequence. virtual int_type overflow(int_type __c = _Traits::eof()); // Convert internal byte sequence to external, char-based // sequence via codecvt. bool _M_convert_to_external(char_type*, streamsize); /** * @brief Manipulates the buffer. * @param __s Pointer to a buffer area. * @param __n Size of @a __s. * @return @c this * * If no file has been opened, and both @a __s and @a __n are zero, then * the stream becomes unbuffered. Otherwise, @c __s is used as a * buffer; see * https://gcc.gnu.org/onlinedocs/libstdc++/manual/streambufs.html#io.streambuf.buffering * for more. */ virtual __streambuf_type* setbuf(char_type* __s, streamsize __n); virtual pos_type seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode = ios_base::in | ios_base::out); virtual pos_type seekpos(pos_type __pos, ios_base::openmode __mode = ios_base::in | ios_base::out); // Common code for seekoff, seekpos, and overflow pos_type _M_seek(off_type __off, ios_base::seekdir __way, __state_type __state); int _M_get_ext_pos(__state_type &__state); virtual int sync(); virtual void imbue(const locale& __loc); virtual streamsize xsgetn(char_type* __s, streamsize __n); virtual streamsize xsputn(const char_type* __s, streamsize __n); // Flushes output buffer, then writes unshift sequence. bool _M_terminate_output(); /** * This function sets the pointers of the internal buffer, both get * and put areas. Typically: * * __off == egptr() - eback() upon underflow/uflow (@b read mode); * __off == 0 upon overflow (@b write mode); * __off == -1 upon open, setbuf, seekoff/pos (@b uncommitted mode). * * NB: epptr() - pbase() == _M_buf_size - 1, since _M_buf_size * reflects the actual allocated memory and the last cell is reserved * for the overflow char of a full put area. */ void _M_set_buffer(streamsize __off) { const bool __testin = _M_mode & ios_base::in; const bool __testout = (_M_mode & ios_base::out || _M_mode & ios_base::app); if (__testin && __off > 0) this->setg(_M_buf, _M_buf, _M_buf + __off); else this->setg(_M_buf, _M_buf, _M_buf); if (__testout && __off == 0 && _M_buf_size > 1 ) this->setp(_M_buf, _M_buf + _M_buf_size - 1); else this->setp(0, 0); } }; // [27.8.1.5] Template class basic_ifstream /** * @brief Controlling input for files. * @ingroup io * * @tparam _CharT Type of character stream. * @tparam _Traits Traits for character type, defaults to * char_traits<_CharT>. * * This class supports reading from named files, using the inherited * functions from std::basic_istream. To control the associated * sequence, an instance of std::basic_filebuf is used, which this page * refers to as @c sb. */ template<typename _CharT, typename _Traits> class basic_ifstream : public basic_istream<_CharT, _Traits> { public: // Types: 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; // Non-standard types: typedef basic_filebuf<char_type, traits_type> __filebuf_type; typedef basic_istream<char_type, traits_type> __istream_type; private: __filebuf_type _M_filebuf; public: // Constructors/Destructors: /** * @brief Default constructor. * * Initializes @c sb using its default constructor, and passes * @c &sb to the base class initializer. Does not open any files * (you haven't given it a filename to open). */ basic_ifstream() : __istream_type(), _M_filebuf() { this->init(&_M_filebuf); } /** * @brief Create an input file stream. * @param __s Null terminated string specifying the filename. * @param __mode Open file in specified mode (see std::ios_base). * * @c ios_base::in is automatically included in @a __mode. */ explicit basic_ifstream(const char* __s, ios_base::openmode __mode = ios_base::in) : __istream_type(), _M_filebuf() { this->init(&_M_filebuf); this->open(__s, __mode); } #if _GLIBCXX_HAVE__WFOPEN && _GLIBCXX_USE_WCHAR_T /** * @param Create an input file stream. * @param __s Wide string specifying the filename. * @param __mode Open file in specified mode (see std::ios_base). * * @c ios_base::in is automatically included in @a __mode. */ basic_ifstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::in) : __istream_type(), _M_filebuf() { this->init(&_M_filebuf); this->open(__s, __mode); } #endif #if __cplusplus >= 201103L /** * @brief Create an input file stream. * @param __s std::string specifying the filename. * @param __mode Open file in specified mode (see std::ios_base). * * @c ios_base::in is automatically included in @a __mode. */ explicit basic_ifstream(const std::string& __s, ios_base::openmode __mode = ios_base::in) : __istream_type(), _M_filebuf() { this->init(&_M_filebuf); this->open(__s, __mode); } #if __cplusplus >= 201703L /** * @brief Create an input file stream. * @param __s filesystem::path specifying the filename. * @param __mode Open file in specified mode (see std::ios_base). * * @c ios_base::in is automatically included in @a __mode. */ template<typename _Path, typename _Require = _If_fs_path<_Path>> basic_ifstream(const _Path& __s, ios_base::openmode __mode = ios_base::in) : basic_ifstream(__s.c_str(), __mode) { } #endif // C++17 basic_ifstream(const basic_ifstream&) = delete; basic_ifstream(basic_ifstream&& __rhs) : __istream_type(std::move(__rhs)), _M_filebuf(std::move(__rhs._M_filebuf)) { __istream_type::set_rdbuf(&_M_filebuf); } #endif // C++11 /** * @brief The destructor does nothing. * * The file is closed by the filebuf object, not the formatting * stream. */ ~basic_ifstream() { } #if __cplusplus >= 201103L // 27.8.3.2 Assign and swap: basic_ifstream& operator=(const basic_ifstream&) = delete; basic_ifstream& operator=(basic_ifstream&& __rhs) { __istream_type::operator=(std::move(__rhs)); _M_filebuf = std::move(__rhs._M_filebuf); return *this; } void swap(basic_ifstream& __rhs) { __istream_type::swap(__rhs); _M_filebuf.swap(__rhs._M_filebuf); } #endif // Members: /** * @brief Accessing the underlying buffer. * @return The current basic_filebuf buffer. * * This hides both signatures of std::basic_ios::rdbuf(). */ __filebuf_type* rdbuf() const { return const_cast<__filebuf_type*>(&_M_filebuf); } /** * @brief Wrapper to test for an open file. * @return @c rdbuf()->is_open() */ bool is_open() { return _M_filebuf.is_open(); } // _GLIBCXX_RESOLVE_LIB_DEFECTS // 365. Lack of const-qualification in clause 27 bool is_open() const { return _M_filebuf.is_open(); } /** * @brief Opens an external file. * @param __s The name of the file. * @param __mode The open mode flags. * * Calls @c std::basic_filebuf::open(s,__mode|in). If that function * fails, @c failbit is set in the stream's error state. */ void open(const char* __s, ios_base::openmode __mode = ios_base::in) { if (!_M_filebuf.open(__s, __mode | ios_base::in)) this->setstate(ios_base::failbit); else // _GLIBCXX_RESOLVE_LIB_DEFECTS // 409. Closing an fstream should clear error state this->clear(); } #if _GLIBCXX_HAVE__WFOPEN && _GLIBCXX_USE_WCHAR_T /** * @brief Opens an external file. * @param __s The name of the file, as a wide character string. * @param __mode The open mode flags. * * Calls @c std::basic_filebuf::open(__s,__mode|in). If that function * fails, @c failbit is set in the stream's error state. */ void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::in) { if (!_M_filebuf.open(__s, __mode | ios_base::in)) this->setstate(ios_base::failbit); else this->clear(); } #endif #if __cplusplus >= 201103L /** * @brief Opens an external file. * @param __s The name of the file. * @param __mode The open mode flags. * * Calls @c std::basic_filebuf::open(__s,__mode|in). If that function * fails, @c failbit is set in the stream's error state. */ void open(const std::string& __s, ios_base::openmode __mode = ios_base::in) { if (!_M_filebuf.open(__s, __mode | ios_base::in)) this->setstate(ios_base::failbit); else // _GLIBCXX_RESOLVE_LIB_DEFECTS // 409. Closing an fstream should clear error state this->clear(); } #if __cplusplus >= 201703L /** * @brief Opens an external file. * @param __s The name of the file, as a filesystem::path. * @param __mode The open mode flags. * * Calls @c std::basic_filebuf::open(__s,__mode|in). If that function * fails, @c failbit is set in the stream's error state. */ template<typename _Path> _If_fs_path<_Path, void> open(const _Path& __s, ios_base::openmode __mode = ios_base::in) { open(__s.c_str(), __mode); } #endif // C++17 #endif // C++11 /** * @brief Close the file. * * Calls @c std::basic_filebuf::close(). If that function * fails, @c failbit is set in the stream's error state. */ void close() { if (!_M_filebuf.close()) this->setstate(ios_base::failbit); } }; // [27.8.1.8] Template class basic_ofstream /** * @brief Controlling output for files. * @ingroup io * * @tparam _CharT Type of character stream. * @tparam _Traits Traits for character type, defaults to * char_traits<_CharT>. * * This class supports reading from named files, using the inherited * functions from std::basic_ostream. To control the associated * sequence, an instance of std::basic_filebuf is used, which this page * refers to as @c sb. */ template<typename _CharT, typename _Traits> class basic_ofstream : public basic_ostream<_CharT,_Traits> { public: // Types: 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; // Non-standard types: typedef basic_filebuf<char_type, traits_type> __filebuf_type; typedef basic_ostream<char_type, traits_type> __ostream_type; private: __filebuf_type _M_filebuf; public: // Constructors: /** * @brief Default constructor. * * Initializes @c sb using its default constructor, and passes * @c &sb to the base class initializer. Does not open any files * (you haven't given it a filename to open). */ basic_ofstream(): __ostream_type(), _M_filebuf() { this->init(&_M_filebuf); } /** * @brief Create an output file stream. * @param __s Null terminated string specifying the filename. * @param __mode Open file in specified mode (see std::ios_base). * * @c ios_base::out is automatically included in @a __mode. */ explicit basic_ofstream(const char* __s, ios_base::openmode __mode = ios_base::out) : __ostream_type(), _M_filebuf() { this->init(&_M_filebuf); this->open(__s, __mode); } #if _GLIBCXX_HAVE__WFOPEN && _GLIBCXX_USE_WCHAR_T /** * @param Create an output file stream. * @param __s Wide string specifying the filename. * @param __mode Open file in specified mode (see std::ios_base). * * @c ios_base::out | @c ios_base::trunc is automatically included in * @a __mode. */ basic_ofstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::out|ios_base::trunc) : __ostream_type(), _M_filebuf() { this->init(&_M_filebuf); this->open(__s, __mode); } #endif #if __cplusplus >= 201103L /** * @brief Create an output file stream. * @param __s std::string specifying the filename. * @param __mode Open file in specified mode (see std::ios_base). * * @c ios_base::out is automatically included in @a __mode. */ explicit basic_ofstream(const std::string& __s, ios_base::openmode __mode = ios_base::out) : __ostream_type(), _M_filebuf() { this->init(&_M_filebuf); this->open(__s, __mode); } #if __cplusplus >= 201703L /** * @brief Create an output file stream. * @param __s filesystem::path specifying the filename. * @param __mode Open file in specified mode (see std::ios_base). * * @c ios_base::out is automatically included in @a __mode. */ template<typename _Path, typename _Require = _If_fs_path<_Path>> basic_ofstream(const _Path& __s, ios_base::openmode __mode = ios_base::out) : basic_ofstream(__s.c_str(), __mode) { } #endif // C++17 basic_ofstream(const basic_ofstream&) = delete; basic_ofstream(basic_ofstream&& __rhs) : __ostream_type(std::move(__rhs)), _M_filebuf(std::move(__rhs._M_filebuf)) { __ostream_type::set_rdbuf(&_M_filebuf); } #endif /** * @brief The destructor does nothing. * * The file is closed by the filebuf object, not the formatting * stream. */ ~basic_ofstream() { } #if __cplusplus >= 201103L // 27.8.3.2 Assign and swap: basic_ofstream& operator=(const basic_ofstream&) = delete; basic_ofstream& operator=(basic_ofstream&& __rhs) { __ostream_type::operator=(std::move(__rhs)); _M_filebuf = std::move(__rhs._M_filebuf); return *this; } void swap(basic_ofstream& __rhs) { __ostream_type::swap(__rhs); _M_filebuf.swap(__rhs._M_filebuf); } #endif // Members: /** * @brief Accessing the underlying buffer. * @return The current basic_filebuf buffer. * * This hides both signatures of std::basic_ios::rdbuf(). */ __filebuf_type* rdbuf() const { return const_cast<__filebuf_type*>(&_M_filebuf); } /** * @brief Wrapper to test for an open file. * @return @c rdbuf()->is_open() */ bool is_open() { return _M_filebuf.is_open(); } // _GLIBCXX_RESOLVE_LIB_DEFECTS // 365. Lack of const-qualification in clause 27 bool is_open() const { return _M_filebuf.is_open(); } /** * @brief Opens an external file. * @param __s The name of the file. * @param __mode The open mode flags. * * Calls @c std::basic_filebuf::open(__s,__mode|out). If that * function fails, @c failbit is set in the stream's error state. */ void open(const char* __s, ios_base::openmode __mode = ios_base::out) { if (!_M_filebuf.open(__s, __mode | ios_base::out)) this->setstate(ios_base::failbit); else // _GLIBCXX_RESOLVE_LIB_DEFECTS // 409. Closing an fstream should clear error state this->clear(); } #if _GLIBCXX_HAVE__WFOPEN && _GLIBCXX_USE_WCHAR_T /** * @brief Opens an external file. * @param __s The name of the file. * @param __mode The open mode flags. * * Calls @c std::basic_filebuf::open(__s,__mode|out). If that * function fails, @c failbit is set in the stream's error state. */ void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::out) { if (!_M_filebuf.open(__s, __mode | ios_base::out)) this->setstate(ios_base::failbit); else this->clear(); } #endif #if __cplusplus >= 201103L /** * @brief Opens an external file. * @param __s The name of the file. * @param __mode The open mode flags. * * Calls @c std::basic_filebuf::open(s,mode|out). If that * function fails, @c failbit is set in the stream's error state. */ void open(const std::string& __s, ios_base::openmode __mode = ios_base::out) { if (!_M_filebuf.open(__s, __mode | ios_base::out)) this->setstate(ios_base::failbit); else // _GLIBCXX_RESOLVE_LIB_DEFECTS // 409. Closing an fstream should clear error state this->clear(); } #if __cplusplus >= 201703L /** * @brief Opens an external file. * @param __s The name of the file, as a filesystem::path. * @param __mode The open mode flags. * * Calls @c std::basic_filebuf::open(__s,__mode|out). If that * function fails, @c failbit is set in the stream's error state. */ template<typename _Path> _If_fs_path<_Path, void> open(const _Path& __s, ios_base::openmode __mode = ios_base::out) { open(__s.c_str(), __mode); } #endif // C++17 #endif // C++11 /** * @brief Close the file. * * Calls @c std::basic_filebuf::close(). If that function * fails, @c failbit is set in the stream's error state. */ void close() { if (!_M_filebuf.close()) this->setstate(ios_base::failbit); } }; // [27.8.1.11] Template class basic_fstream /** * @brief Controlling input and output for files. * @ingroup io * * @tparam _CharT Type of character stream. * @tparam _Traits Traits for character type, defaults to * char_traits<_CharT>. * * This class supports reading from and writing to named files, using * the inherited functions from std::basic_iostream. To control the * associated sequence, an instance of std::basic_filebuf is used, which * this page refers to as @c sb. */ template<typename _CharT, typename _Traits> class basic_fstream : public basic_iostream<_CharT, _Traits> { public: // Types: 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; // Non-standard types: typedef basic_filebuf<char_type, traits_type> __filebuf_type; typedef basic_ios<char_type, traits_type> __ios_type; typedef basic_iostream<char_type, traits_type> __iostream_type; private: __filebuf_type _M_filebuf; public: // Constructors/destructor: /** * @brief Default constructor. * * Initializes @c sb using its default constructor, and passes * @c &sb to the base class initializer. Does not open any files * (you haven't given it a filename to open). */ basic_fstream() : __iostream_type(), _M_filebuf() { this->init(&_M_filebuf); } /** * @brief Create an input/output file stream. * @param __s Null terminated string specifying the filename. * @param __mode Open file in specified mode (see std::ios_base). */ explicit basic_fstream(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out) : __iostream_type(0), _M_filebuf() { this->init(&_M_filebuf); this->open(__s, __mode); } #if _GLIBCXX_HAVE__WFOPEN && _GLIBCXX_USE_WCHAR_T /** * @param Create an input/output file stream. * @param __s Wide string specifying the filename. * @param __mode Open file in specified mode (see std::ios_base). */ basic_fstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::in | ios_base::out) : __iostream_type(0), _M_filebuf() { this->init(&_M_filebuf); this->open(__s, __mode); } #endif #if __cplusplus >= 201103L /** * @brief Create an input/output file stream. * @param __s Null terminated string specifying the filename. * @param __mode Open file in specified mode (see std::ios_base). */ explicit basic_fstream(const std::string& __s, ios_base::openmode __mode = ios_base::in | ios_base::out) : __iostream_type(0), _M_filebuf() { this->init(&_M_filebuf); this->open(__s, __mode); } #if __cplusplus >= 201703L /** * @brief Create an input/output file stream. * @param __s filesystem::path specifying the filename. * @param __mode Open file in specified mode (see std::ios_base). */ template<typename _Path, typename _Require = _If_fs_path<_Path>> basic_fstream(const _Path& __s, ios_base::openmode __mode = ios_base::in | ios_base::out) : basic_fstream(__s.c_str(), __mode) { } #endif // C++17 basic_fstream(const basic_fstream&) = delete; basic_fstream(basic_fstream&& __rhs) : __iostream_type(std::move(__rhs)), _M_filebuf(std::move(__rhs._M_filebuf)) { __iostream_type::set_rdbuf(&_M_filebuf); } #endif /** * @brief The destructor does nothing. * * The file is closed by the filebuf object, not the formatting * stream. */ ~basic_fstream() { } #if __cplusplus >= 201103L // 27.8.3.2 Assign and swap: basic_fstream& operator=(const basic_fstream&) = delete; basic_fstream& operator=(basic_fstream&& __rhs) { __iostream_type::operator=(std::move(__rhs)); _M_filebuf = std::move(__rhs._M_filebuf); return *this; } void swap(basic_fstream& __rhs) { __iostream_type::swap(__rhs); _M_filebuf.swap(__rhs._M_filebuf); } #endif // Members: /** * @brief Accessing the underlying buffer. * @return The current basic_filebuf buffer. * * This hides both signatures of std::basic_ios::rdbuf(). */ __filebuf_type* rdbuf() const { return const_cast<__filebuf_type*>(&_M_filebuf); } /** * @brief Wrapper to test for an open file. * @return @c rdbuf()->is_open() */ bool is_open() { return _M_filebuf.is_open(); } // _GLIBCXX_RESOLVE_LIB_DEFECTS // 365. Lack of const-qualification in clause 27 bool is_open() const { return _M_filebuf.is_open(); } /** * @brief Opens an external file. * @param __s The name of the file. * @param __mode The open mode flags. * * Calls @c std::basic_filebuf::open(__s,__mode). If that * function fails, @c failbit is set in the stream's error state. */ void open(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out) { if (!_M_filebuf.open(__s, __mode)) this->setstate(ios_base::failbit); else // _GLIBCXX_RESOLVE_LIB_DEFECTS // 409. Closing an fstream should clear error state this->clear(); } #if _GLIBCXX_HAVE__WFOPEN && _GLIBCXX_USE_WCHAR_T /** * @brief Opens an external file. * @param __s The name of the file. * @param __mode The open mode flags. * * Calls @c std::basic_filebuf::open(__s,__mode). If that * function fails, @c failbit is set in the stream's error state. */ void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::in | ios_base::out) { if (!_M_filebuf.open(__s, __mode)) this->setstate(ios_base::failbit); else this->clear(); } #endif #if __cplusplus >= 201103L /** * @brief Opens an external file. * @param __s The name of the file. * @param __mode The open mode flags. * * Calls @c std::basic_filebuf::open(__s,__mode). If that * function fails, @c failbit is set in the stream's error state. */ void open(const std::string& __s, ios_base::openmode __mode = ios_base::in | ios_base::out) { if (!_M_filebuf.open(__s, __mode)) this->setstate(ios_base::failbit); else // _GLIBCXX_RESOLVE_LIB_DEFECTS // 409. Closing an fstream should clear error state this->clear(); } #if __cplusplus >= 201703L /** * @brief Opens an external file. * @param __s The name of the file, as a filesystem::path. * @param __mode The open mode flags. * * Calls @c std::basic_filebuf::open(__s,__mode). If that * function fails, @c failbit is set in the stream's error state. */ template<typename _Path> _If_fs_path<_Path, void> open(const _Path& __s, ios_base::openmode __mode = ios_base::in | ios_base::out) { open(__s.c_str(), __mode); } #endif // C++17 #endif // C++11 /** * @brief Close the file. * * Calls @c std::basic_filebuf::close(). If that function * fails, @c failbit is set in the stream's error state. */ void close() { if (!_M_filebuf.close()) this->setstate(ios_base::failbit); } }; #if __cplusplus >= 201103L /// Swap specialization for filebufs. template <class _CharT, class _Traits> inline void swap(basic_filebuf<_CharT, _Traits>& __x, basic_filebuf<_CharT, _Traits>& __y) { __x.swap(__y); } /// Swap specialization for ifstreams. template <class _CharT, class _Traits> inline void swap(basic_ifstream<_CharT, _Traits>& __x, basic_ifstream<_CharT, _Traits>& __y) { __x.swap(__y); } /// Swap specialization for ofstreams. template <class _CharT, class _Traits> inline void swap(basic_ofstream<_CharT, _Traits>& __x, basic_ofstream<_CharT, _Traits>& __y) { __x.swap(__y); } /// Swap specialization for fstreams. template <class _CharT, class _Traits> inline void swap(basic_fstream<_CharT, _Traits>& __x, basic_fstream<_CharT, _Traits>& __y) { __x.swap(__y); } #endif _GLIBCXX_END_NAMESPACE_VERSION } // namespace #include <bits/fstream.tcc> #endif /* _GLIBCXX_FSTREAM */