// Iostreams base classes -*- C++ -*- // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 // 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 2, 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. // You should have received a copy of the GNU General Public License along // with this library; see the file COPYING. If not, write to the Free // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, // USA. // As a special exception, you may use this file as part of a free software // library without restriction. Specifically, if other files instantiate // templates or use macros or inline functions from this file, or you compile // this file and link it with other files to produce an executable, this // file does not by itself cause the resulting executable to be covered by // the GNU General Public License. This exception does not however // invalidate any other reasons why the executable file might be covered by // the GNU General Public License. // // ISO C++ 14882: 27.4 Iostreams base classes // /** @file ios_base.h * This is an internal header file, included by other library headers. * You should not attempt to use it directly. */ #ifndef _IOS_BASE_H #define _IOS_BASE_H 1 #pragma GCC system_header #include #include #include namespace std { // The following definitions of bitmask types are enums, not ints, // as permitted (but not required) in the standard, in order to provide // better type safety in iostream calls. A side effect is that // expressions involving them are no longer compile-time constants. enum _Ios_Fmtflags { _S_ios_fmtflags_end = 1L << 16 }; inline _Ios_Fmtflags operator&(_Ios_Fmtflags __a, _Ios_Fmtflags __b) { return _Ios_Fmtflags(static_cast(__a) & static_cast(__b)); } inline _Ios_Fmtflags operator|(_Ios_Fmtflags __a, _Ios_Fmtflags __b) { return _Ios_Fmtflags(static_cast(__a) | static_cast(__b)); } inline _Ios_Fmtflags operator^(_Ios_Fmtflags __a, _Ios_Fmtflags __b) { return _Ios_Fmtflags(static_cast(__a) ^ static_cast(__b)); } inline _Ios_Fmtflags operator|=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b) { return __a = __a | __b; } inline _Ios_Fmtflags operator&=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b) { return __a = __a & __b; } inline _Ios_Fmtflags operator^=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b) { return __a = __a ^ __b; } inline _Ios_Fmtflags operator~(_Ios_Fmtflags __a) { return _Ios_Fmtflags(~static_cast(__a)); } enum _Ios_Openmode { _S_ios_openmode_end = 1L << 16 }; inline _Ios_Openmode operator&(_Ios_Openmode __a, _Ios_Openmode __b) { return _Ios_Openmode(static_cast(__a) & static_cast(__b)); } inline _Ios_Openmode operator|(_Ios_Openmode __a, _Ios_Openmode __b) { return _Ios_Openmode(static_cast(__a) | static_cast(__b)); } inline _Ios_Openmode operator^(_Ios_Openmode __a, _Ios_Openmode __b) { return _Ios_Openmode(static_cast(__a) ^ static_cast(__b)); } inline _Ios_Openmode operator|=(_Ios_Openmode& __a, _Ios_Openmode __b) { return __a = __a | __b; } inline _Ios_Openmode operator&=(_Ios_Openmode& __a, _Ios_Openmode __b) { return __a = __a & __b; } inline _Ios_Openmode operator^=(_Ios_Openmode& __a, _Ios_Openmode __b) { return __a = __a ^ __b; } inline _Ios_Openmode operator~(_Ios_Openmode __a) { return _Ios_Openmode(~static_cast(__a)); } enum _Ios_Iostate { _S_ios_iostate_end = 1L << 16 }; inline _Ios_Iostate operator&(_Ios_Iostate __a, _Ios_Iostate __b) { return _Ios_Iostate(static_cast(__a) & static_cast(__b)); } inline _Ios_Iostate operator|(_Ios_Iostate __a, _Ios_Iostate __b) { return _Ios_Iostate(static_cast(__a) | static_cast(__b)); } inline _Ios_Iostate operator^(_Ios_Iostate __a, _Ios_Iostate __b) { return _Ios_Iostate(static_cast(__a) ^ static_cast(__b)); } inline _Ios_Iostate operator|=(_Ios_Iostate& __a, _Ios_Iostate __b) { return __a = __a | __b; } inline _Ios_Iostate operator&=(_Ios_Iostate& __a, _Ios_Iostate __b) { return __a = __a & __b; } inline _Ios_Iostate operator^=(_Ios_Iostate& __a, _Ios_Iostate __b) { return __a = __a ^ __b; } inline _Ios_Iostate operator~(_Ios_Iostate __a) { return _Ios_Iostate(~static_cast(__a)); } enum _Ios_Seekdir { _S_ios_seekdir_end = 1L << 16 }; // 27.4.2 Class ios_base /** * @brief The very top of the I/O class hierarchy. * * This class defines everything that can be defined about I/O that does * not depend on the type of characters being input or output. Most * people will only see @c ios_base when they need to specify the full * name of the various I/O flags (e.g., the openmodes). */ class ios_base { public: // 27.4.2.1.1 Class ios_base::failure /// These are thrown to indicate problems. Doc me. class failure : public exception { public: // _GLIBCXX_RESOLVE_LIB_DEFECTS // 48. Use of non-existent exception constructor explicit failure(const string& __str) throw(); // This declaration is not useless: // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118 virtual ~failure() throw(); virtual const char* what() const throw(); private: string _M_msg; }; // 27.4.2.1.2 Type ios_base::fmtflags /** * @brief This is a bitmask type. * * @c "_Ios_Fmtflags" is implementation-defined, but it is valid to * perform bitwise operations on these values and expect the Right * Thing to happen. Defined objects of type fmtflags are: * - boolalpha * - dec * - fixed * - hex * - internal * - left * - oct * - right * - scientific * - showbase * - showpoint * - showpos * - skipws * - unitbuf * - uppercase * - adjustfield * - basefield * - floatfield */ typedef _Ios_Fmtflags fmtflags; /// Insert/extract @c bool in alphabetic rather than numeric format. static const fmtflags boolalpha = fmtflags(__ios_flags::_S_boolalpha); /// Converts integer input or generates integer output in decimal base. static const fmtflags dec = fmtflags(__ios_flags::_S_dec); /// Generate floating-point output in fixed-point notation. static const fmtflags fixed = fmtflags(__ios_flags::_S_fixed); /// Converts integer input or generates integer output in hexadecimal base. static const fmtflags hex = fmtflags(__ios_flags::_S_hex); /// Adds fill characters at a designated internal point in certain /// generated output, or identical to @c right if no such point is /// designated. static const fmtflags internal = fmtflags(__ios_flags::_S_internal); /// Adds fill characters on the right (final positions) of certain /// generated output. (I.e., the thing you print is flush left.) static const fmtflags left = fmtflags(__ios_flags::_S_left); /// Converts integer input or generates integer output in octal base. static const fmtflags oct = fmtflags(__ios_flags::_S_oct); /// Adds fill characters on the left (initial positions) of certain /// generated output. (I.e., the thing you print is flush right.) static const fmtflags right = fmtflags(__ios_flags::_S_right); /// Generates floating-point output in scientific notation. static const fmtflags scientific = fmtflags(__ios_flags::_S_scientific); /// Generates a prefix indicating the numeric base of generated integer /// output. static const fmtflags showbase = fmtflags(__ios_flags::_S_showbase); /// Generates a decimal-point character unconditionally in generated /// floating-point output. static const fmtflags showpoint = fmtflags(__ios_flags::_S_showpoint); /// Generates a + sign in non-negative generated numeric output. static const fmtflags showpos = fmtflags(__ios_flags::_S_showpos); /// Skips leading white space before certain input operations. static const fmtflags skipws = fmtflags(__ios_flags::_S_skipws); /// Flushes output after each output operation. static const fmtflags unitbuf = fmtflags(__ios_flags::_S_unitbuf); /// Replaces certain lowercase letters with their uppercase equivalents /// in generated output. static const fmtflags uppercase = fmtflags(__ios_flags::_S_uppercase); /// A mask of left|right|internal. Useful for the 2-arg form of @c setf. static const fmtflags adjustfield = fmtflags(__ios_flags::_S_adjustfield); /// A mask of dec|oct|hex. Useful for the 2-arg form of @c setf. static const fmtflags basefield = fmtflags(__ios_flags::_S_basefield); /// A mask of scientific|fixed. Useful for the 2-arg form of @c setf. static const fmtflags floatfield = fmtflags(__ios_flags::_S_floatfield); // 27.4.2.1.3 Type ios_base::iostate /** * @brief This is a bitmask type. * * @c "_Ios_Iostate" is implementation-defined, but it is valid to * perform bitwise operations on these values and expect the Right * Thing to happen. Defined objects of type iostate are: * - badbit * - eofbit * - failbit * - goodbit */ typedef _Ios_Iostate iostate; /// Indicates a loss of integrity in an input or output sequence (such /// as an irrecoverable read error from a file). static const iostate badbit = iostate(__ios_flags::_S_badbit); /// Indicates that an input operation reached the end of an input sequence. static const iostate eofbit = iostate(__ios_flags::_S_eofbit); /// Indicates that an input operation failed to read the expected /// characters, or that an output operation failed to generate the /// desired characters. static const iostate failbit = iostate(__ios_flags::_S_failbit); /// Indicates all is well. static const iostate goodbit = iostate(0); // 27.4.2.1.4 Type ios_base::openmode /** * @brief This is a bitmask type. * * @c "_Ios_Openmode" is implementation-defined, but it is valid to * perform bitwise operations on these values and expect the Right * Thing to happen. Defined objects of type openmode are: * - app * - ate * - binary * - in * - out * - trunc */ typedef _Ios_Openmode openmode; /// Seek to end before each write. static const openmode app = openmode(__ios_flags::_S_app); /// Open and seek to end immediately after opening. static const openmode ate = openmode(__ios_flags::_S_ate); /// Perform input and output in binary mode (as opposed to text mode). /// This is probably not what you think it is; see /// http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#3 and /// http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#7 for more. static const openmode binary = openmode(__ios_flags::_S_bin); /// Open for input. Default for @c ifstream and fstream. static const openmode in = openmode(__ios_flags::_S_in); /// Open for output. Default for @c ofstream and fstream. static const openmode out = openmode(__ios_flags::_S_out); /// Open for input. Default for @c ofstream. static const openmode trunc = openmode(__ios_flags::_S_trunc); // 27.4.2.1.5 Type ios_base::seekdir /** * @brief This is an enumerated type. * * @c "_Ios_Seekdir" is implementation-defined. Defined values * of type seekdir are: * - beg * - cur, equivalent to @c SEEK_CUR in the C standard library. * - end, equivalent to @c SEEK_END in the C standard library. */ typedef _Ios_Seekdir seekdir; /// Request a seek relative to the beginning of the stream. static const seekdir beg = seekdir(0); /// Request a seek relative to the current position within the sequence. static const seekdir cur = seekdir(SEEK_CUR); /// Request a seek relative to the current end of the sequence. static const seekdir end = seekdir(SEEK_END); #ifdef _GLIBCXX_DEPRECATED // Annex D.6 typedef int io_state; typedef int open_mode; typedef int seek_dir; typedef std::streampos streampos; typedef std::streamoff streamoff; #endif // Callbacks; /** * @brief The set of events that may be passed to an event callback. * * erase_event is used during ~ios() and copyfmt(). imbue_event is used * during imbue(). copyfmt_event is used during copyfmt(). */ enum event { erase_event, imbue_event, copyfmt_event }; /** * @brief The type of an event callback function. * @param event One of the members of the event enum. * @param ios_base Reference to the ios_base object. * @param int The integer provided when the callback was registered. * * Event callbacks are user defined functions that get called during * several ios_base and basic_ios functions, specifically imbue(), * copyfmt(), and ~ios(). */ typedef void (*event_callback) (event, ios_base&, int); /** * @brief Add the callback __fn with parameter __index. * @param __fn The function to add. * @param __index The integer to pass to the function when invoked. * * Registers a function as an event callback with an integer parameter to * be passed to the function when invoked. Multiple copies of the * function are allowed. If there are multiple callbacks, they are * invoked in the order they were registered. */ void register_callback(event_callback __fn, int __index); protected: //@{ /** * @if maint * ios_base data members (doc me) * @endif */ streamsize _M_precision; streamsize _M_width; fmtflags _M_flags; iostate _M_exception; iostate _M_streambuf_state; //@} // 27.4.2.6 Members for callbacks // 27.4.2.6 ios_base callbacks struct _Callback_list { // Data Members _Callback_list* _M_next; ios_base::event_callback _M_fn; int _M_index; _Atomic_word _M_refcount; // 0 means one reference. _Callback_list(ios_base::event_callback __fn, int __index, _Callback_list* __cb) : _M_next(__cb), _M_fn(__fn), _M_index(__index), _M_refcount(0) { } void _M_add_reference() { __gnu_cxx::__atomic_add(&_M_refcount, 1); } // 0 => OK to delete. int _M_remove_reference() { return __gnu_cxx::__exchange_and_add(&_M_refcount, -1); } }; _Callback_list* _M_callbacks; void _M_call_callbacks(event __ev) throw(); void _M_dispose_callbacks(void); // 27.4.2.5 Members for iword/pword storage struct _Words { void* _M_pword; long _M_iword; _Words() : _M_pword(0), _M_iword(0) { } }; // Only for failed iword/pword calls. _Words _M_word_zero; // Guaranteed storage. // The first 5 iword and pword slots are reserved for internal use. static const int _S_local_word_size = 8; _Words _M_local_word[_S_local_word_size]; // Allocated storage. int _M_word_size; _Words* _M_word; _Words& _M_grow_words(int __index, bool __iword); // Members for locale and locale caching. locale _M_ios_locale; void _M_init(); public: // 27.4.2.1.6 Class ios_base::Init // Used to initialize standard streams. In theory, g++ could use // -finit-priority to order this stuff correctly without going // through these machinations. class Init { friend class ios_base; public: Init(); ~Init(); private: static _Atomic_word _S_refcount; static bool _S_synced_with_stdio; }; // [27.4.2.2] fmtflags state functions /** * @brief Access to format flags. * @return The format control flags for both input and output. */ inline fmtflags flags() const { return _M_flags; } /** * @brief Setting new format flags all at once. * @param fmtfl The new flags to set. * @return The previous format control flags. * * This function overwrites all the format flags with @a fmtfl. */ inline fmtflags flags(fmtflags __fmtfl) { fmtflags __old = _M_flags; _M_flags = __fmtfl; return __old; } /** * @brief Setting new format flags. * @param fmtfl Additional flags to set. * @return The previous format control flags. * * This function sets additional flags in format control. Flags that * were previously set remain set. */ inline fmtflags setf(fmtflags __fmtfl) { fmtflags __old = _M_flags; _M_flags |= __fmtfl; return __old; } /** * @brief Setting new format flags. * @param fmtfl Additional flags to set. * @param mask The flags mask for @a fmtfl. * @return The previous format control flags. * * This function clears @a mask in the format flags, then sets * @a fmtfl @c & @a mask. An example mask is @c ios_base::adjustfield. */ inline fmtflags setf(fmtflags __fmtfl, fmtflags __mask) { fmtflags __old = _M_flags; _M_flags &= ~__mask; _M_flags |= (__fmtfl & __mask); return __old; } /** * @brief Clearing format flags. * @param mask The flags to unset. * * This function clears @a mask in the format flags. */ inline void unsetf(fmtflags __mask) { _M_flags &= ~__mask; } /** * @brief Flags access. * @return The precision to generate on certain output operations. * * @if maint * Be careful if you try to give a definition of "precision" here; see * DR 189. * @endif */ inline streamsize precision() const { return _M_precision; } /** * @brief Changing flags. * @param prec The new precision value. * @return The previous value of precision(). */ inline streamsize precision(streamsize __prec) { streamsize __old = _M_precision; _M_precision = __prec; return __old; } /** * @brief Flags access. * @return The minimum field width to generate on output operations. * * "Minimum field width" refers to the number of characters. */ inline streamsize width() const { return _M_width; } /** * @brief Changing flags. * @param wide The new width value. * @return The previous value of width(). */ inline streamsize width(streamsize __wide) { streamsize __old = _M_width; _M_width = __wide; return __old; } // [27.4.2.4] ios_base static members /** * @brief Interaction with the standard C I/O objects. * @param sync Whether to synchronize or not. * @return True if the standard streams were previously synchronized. * * The synchronization referred to is @e only that between the standard * C facilities (e.g., stdout) and the standard C++ objects (e.g., * cout). User-declared streams are unaffected. See * http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#8 for more. */ static bool sync_with_stdio(bool __sync = true); // [27.4.2.3] ios_base locale functions /** * @brief Setting a new locale. * @param loc The new locale. * @return The previous locale. * * Sets the new locale for this stream, and then invokes each callback * with imbue_event. */ locale imbue(const locale& __loc); /** * @brief Locale access * @return A copy of the current locale. * * If @c imbue(loc) has previously been called, then this function * returns @c loc. Otherwise, it returns a copy of @c std::locale(), * the global C++ locale. */ inline locale getloc() const { return _M_ios_locale; } /** * @brief Locale access * @return A reference to the current locale. * * Like getloc above, but returns a reference instead of * generating a copy. */ inline const locale& _M_getloc() const { return _M_ios_locale; } // [27.4.2.5] ios_base storage functions /** * @brief Access to unique indices. * @return An integer different from all previous calls. * * This function returns a unique integer every time it is called. It * can be used for any purpose, but is primarily intended to be a unique * index for the iword and pword functions. The expectation is that an * application calls xalloc in order to obtain an index in the iword and * pword arrays that can be used without fear of conflict. * * The implementation maintains a static variable that is incremented and * returned on each invocation. xalloc is guaranteed to return an index * that is safe to use in the iword and pword arrays. */ static int xalloc() throw(); /** * @brief Access to integer array. * @param __ix Index into the array. * @return A reference to an integer associated with the index. * * The iword function provides access to an array of integers that can be * used for any purpose. The array grows as required to hold the * supplied index. All integers in the array are initialized to 0. * * The implementation reserves several indices. You should use xalloc to * obtain an index that is safe to use. Also note that since the array * can grow dynamically, it is not safe to hold onto the reference. */ inline long& iword(int __ix) { _Words& __word = (__ix < _M_word_size) ? _M_word[__ix] : _M_grow_words(__ix, true); return __word._M_iword; } /** * @brief Access to void pointer array. * @param __ix Index into the array. * @return A reference to a void* associated with the index. * * The pword function provides access to an array of pointers that can be * used for any purpose. The array grows as required to hold the * supplied index. All pointers in the array are initialized to 0. * * The implementation reserves several indices. You should use xalloc to * obtain an index that is safe to use. Also note that since the array * can grow dynamically, it is not safe to hold onto the reference. */ inline void*& pword(int __ix) { _Words& __word = (__ix < _M_word_size) ? _M_word[__ix] : _M_grow_words(__ix, false); return __word._M_pword; } // Destructor /** * Invokes each callback with erase_event. Destroys local storage. * * Note that the ios_base object for the standard streams never gets * destroyed. As a result, any callbacks registered with the standard * streams will not get invoked with erase_event (unless copyfmt is * used). */ virtual ~ios_base(); protected: ios_base(); // _GLIBCXX_RESOLVE_LIB_DEFECTS // 50. Copy constructor and assignment operator of ios_base private: ios_base(const ios_base&); ios_base& operator=(const ios_base&); }; // [27.4.5.1] fmtflags manipulators /// Calls base.setf(ios_base::boolalpha). inline ios_base& boolalpha(ios_base& __base) { __base.setf(ios_base::boolalpha); return __base; } /// Calls base.unsetf(ios_base::boolalpha). inline ios_base& noboolalpha(ios_base& __base) { __base.unsetf(ios_base::boolalpha); return __base; } /// Calls base.setf(ios_base::showbase). inline ios_base& showbase(ios_base& __base) { __base.setf(ios_base::showbase); return __base; } /// Calls base.unsetf(ios_base::showbase). inline ios_base& noshowbase(ios_base& __base) { __base.unsetf(ios_base::showbase); return __base; } /// Calls base.setf(ios_base::showpoint). inline ios_base& showpoint(ios_base& __base) { __base.setf(ios_base::showpoint); return __base; } /// Calls base.unsetf(ios_base::showpoint). inline ios_base& noshowpoint(ios_base& __base) { __base.unsetf(ios_base::showpoint); return __base; } /// Calls base.setf(ios_base::showpos). inline ios_base& showpos(ios_base& __base) { __base.setf(ios_base::showpos); return __base; } /// Calls base.unsetf(ios_base::showpos). inline ios_base& noshowpos(ios_base& __base) { __base.unsetf(ios_base::showpos); return __base; } /// Calls base.setf(ios_base::skipws). inline ios_base& skipws(ios_base& __base) { __base.setf(ios_base::skipws); return __base; } /// Calls base.unsetf(ios_base::skipws). inline ios_base& noskipws(ios_base& __base) { __base.unsetf(ios_base::skipws); return __base; } /// Calls base.setf(ios_base::uppercase). inline ios_base& uppercase(ios_base& __base) { __base.setf(ios_base::uppercase); return __base; } /// Calls base.unsetf(ios_base::uppercase). inline ios_base& nouppercase(ios_base& __base) { __base.unsetf(ios_base::uppercase); return __base; } /// Calls base.setf(ios_base::unitbuf). inline ios_base& unitbuf(ios_base& __base) { __base.setf(ios_base::unitbuf); return __base; } /// Calls base.unsetf(ios_base::unitbuf). inline ios_base& nounitbuf(ios_base& __base) { __base.unsetf(ios_base::unitbuf); return __base; } // [27.4.5.2] adjustfield anipulators /// Calls base.setf(ios_base::internal, ios_base::adjustfield). inline ios_base& internal(ios_base& __base) { __base.setf(ios_base::internal, ios_base::adjustfield); return __base; } /// Calls base.setf(ios_base::left, ios_base::adjustfield). inline ios_base& left(ios_base& __base) { __base.setf(ios_base::left, ios_base::adjustfield); return __base; } /// Calls base.setf(ios_base::right, ios_base::adjustfield). inline ios_base& right(ios_base& __base) { __base.setf(ios_base::right, ios_base::adjustfield); return __base; } // [27.4.5.3] basefield anipulators /// Calls base.setf(ios_base::dec, ios_base::basefield). inline ios_base& dec(ios_base& __base) { __base.setf(ios_base::dec, ios_base::basefield); return __base; } /// Calls base.setf(ios_base::hex, ios_base::basefield). inline ios_base& hex(ios_base& __base) { __base.setf(ios_base::hex, ios_base::basefield); return __base; } /// Calls base.setf(ios_base::oct, ios_base::basefield). inline ios_base& oct(ios_base& __base) { __base.setf(ios_base::oct, ios_base::basefield); return __base; } // [27.4.5.4] floatfield anipulators /// Calls base.setf(ios_base::fixed, ios_base::floatfield). inline ios_base& fixed(ios_base& __base) { __base.setf(ios_base::fixed, ios_base::floatfield); return __base; } /// Calls base.setf(ios_base::scientific, ios_base::floatfield). inline ios_base& scientific(ios_base& __base) { __base.setf(ios_base::scientific, ios_base::floatfield); return __base; } } // namespace std #endif /* _IOS_BASE_H */