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Diffstat (limited to 'gcc-4.4.3/libstdc++-v3/include/std/streambuf')
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diff --git a/gcc-4.4.3/libstdc++-v3/include/std/streambuf b/gcc-4.4.3/libstdc++-v3/include/std/streambuf new file mode 100644 index 000000000..790be0ec4 --- /dev/null +++ b/gcc-4.4.3/libstdc++-v3/include/std/streambuf @@ -0,0 +1,799 @@ +// Stream buffer classes -*- C++ -*- + +// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, +// 2006, 2007, 2008, 2009 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 streambuf + * This is a Standard C++ Library header. + */ + +// +// ISO C++ 14882: 27.5 Stream buffers +// + +#ifndef _GLIBXX_STREAMBUF +#define _GLIBXX_STREAMBUF 1 + +#pragma GCC system_header + +#include <bits/c++config.h> +#include <iosfwd> +#include <bits/localefwd.h> +#include <bits/ios_base.h> +#include <bits/cpp_type_traits.h> +#include <ext/type_traits.h> + +_GLIBCXX_BEGIN_NAMESPACE(std) + + template<typename _CharT, typename _Traits> + streamsize + __copy_streambufs_eof(basic_streambuf<_CharT, _Traits>*, + basic_streambuf<_CharT, _Traits>*, bool&); + + /** + * @brief The actual work of input and output (interface). + * + * This is a base class. Derived stream buffers each control a + * pair of character sequences: one for input, and one for output. + * + * Section [27.5.1] of the standard describes the requirements and + * behavior of stream buffer classes. That section (three paragraphs) + * is reproduced here, for simplicity and accuracy. + * + * -# Stream buffers can impose various constraints on the sequences + * they control. Some constraints are: + * - The controlled input sequence can be not readable. + * - The controlled output sequence can be not writable. + * - The controlled sequences can be associated with the contents of + * other representations for character sequences, such as external + * files. + * - The controlled sequences can support operations @e directly to or + * from associated sequences. + * - The controlled sequences can impose limitations on how the + * program can read characters from a sequence, write characters to + * a sequence, put characters back into an input sequence, or alter + * the stream position. + * . + * -# Each sequence is characterized by three pointers which, if non-null, + * all point into the same @c charT array object. The array object + * represents, at any moment, a (sub)sequence of characters from the + * sequence. Operations performed on a sequence alter the values + * stored in these pointers, perform reads and writes directly to or + * from associated sequences, and alter "the stream position" and + * conversion state as needed to maintain this subsequence relationship. + * The three pointers are: + * - the <em>beginning pointer</em>, or lowest element address in the + * array (called @e xbeg here); + * - the <em>next pointer</em>, or next element address that is a + * current candidate for reading or writing (called @e xnext here); + * - the <em>end pointer</em>, or first element address beyond the + * end of the array (called @e xend here). + * . + * -# The following semantic constraints shall always apply for any set + * of three pointers for a sequence, using the pointer names given + * immediately above: + * - If @e xnext is not a null pointer, then @e xbeg and @e xend shall + * also be non-null pointers into the same @c charT array, as + * described above; otherwise, @e xbeg and @e xend shall also be null. + * - If @e xnext is not a null pointer and @e xnext < @e xend for an + * output sequence, then a <em>write position</em> is available. + * In this case, @e *xnext shall be assignable as the next element + * to write (to put, or to store a character value, into the sequence). + * - If @e xnext is not a null pointer and @e xbeg < @e xnext for an + * input sequence, then a <em>putback position</em> is available. + * In this case, @e xnext[-1] shall have a defined value and is the + * next (preceding) element to store a character that is put back + * into the input sequence. + * - If @e xnext is not a null pointer and @e xnext< @e xend for an + * input sequence, then a <em>read position</em> is available. + * In this case, @e *xnext shall have a defined value and is the + * next element to read (to get, or to obtain a character value, + * from the sequence). + */ + template<typename _CharT, typename _Traits> + class basic_streambuf + { + public: + //@{ + /** + * These are standard types. They permit a standardized way of + * referring to names of (or names dependant on) the template + * parameters, which are specific to the implementation. + */ + 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; + //@} + + //@{ + /// This is a non-standard type. + typedef basic_streambuf<char_type, traits_type> __streambuf_type; + //@} + + friend class basic_ios<char_type, traits_type>; + friend class basic_istream<char_type, traits_type>; + friend class basic_ostream<char_type, traits_type>; + friend class istreambuf_iterator<char_type, traits_type>; + friend class ostreambuf_iterator<char_type, traits_type>; + + friend streamsize + __copy_streambufs_eof<>(__streambuf_type*, __streambuf_type*, bool&); + + template<bool _IsMove, typename _CharT2> + friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, + _CharT2*>::__type + __copy_move_a2(istreambuf_iterator<_CharT2>, + istreambuf_iterator<_CharT2>, _CharT2*); + + template<typename _CharT2> + friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, + istreambuf_iterator<_CharT2> >::__type + find(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>, + const _CharT2&); + + template<typename _CharT2, typename _Traits2> + friend basic_istream<_CharT2, _Traits2>& + operator>>(basic_istream<_CharT2, _Traits2>&, _CharT2*); + + template<typename _CharT2, typename _Traits2, typename _Alloc> + friend basic_istream<_CharT2, _Traits2>& + operator>>(basic_istream<_CharT2, _Traits2>&, + basic_string<_CharT2, _Traits2, _Alloc>&); + + template<typename _CharT2, typename _Traits2, typename _Alloc> + friend basic_istream<_CharT2, _Traits2>& + getline(basic_istream<_CharT2, _Traits2>&, + basic_string<_CharT2, _Traits2, _Alloc>&, _CharT2); + + protected: + //@{ + /** + * This is based on _IO_FILE, just reordered to be more consistent, + * and is intended to be the most minimal abstraction for an + * internal buffer. + * - get == input == read + * - put == output == write + */ + char_type* _M_in_beg; // Start of get area. + char_type* _M_in_cur; // Current read area. + char_type* _M_in_end; // End of get area. + char_type* _M_out_beg; // Start of put area. + char_type* _M_out_cur; // Current put area. + char_type* _M_out_end; // End of put area. + + /// Current locale setting. + locale _M_buf_locale; + + public: + /// Destructor deallocates no buffer space. + virtual + ~basic_streambuf() + { } + + // [27.5.2.2.1] locales + /** + * @brief Entry point for imbue(). + * @param loc The new locale. + * @return The previous locale. + * + * Calls the derived imbue(loc). + */ + locale + pubimbue(const locale &__loc) + { + locale __tmp(this->getloc()); + this->imbue(__loc); + _M_buf_locale = __loc; + return __tmp; + } + + /** + * @brief Locale access. + * @return The current locale in effect. + * + * If pubimbue(loc) has been called, then the most recent @c loc + * is returned. Otherwise the global locale in effect at the time + * of construction is returned. + */ + locale + getloc() const + { return _M_buf_locale; } + + // [27.5.2.2.2] buffer management and positioning + //@{ + /** + * @brief Entry points for derived buffer functions. + * + * The public versions of @c pubfoo dispatch to the protected + * derived @c foo member functions, passing the arguments (if any) + * and returning the result unchanged. + */ + __streambuf_type* + pubsetbuf(char_type* __s, streamsize __n) + { return this->setbuf(__s, __n); } + + pos_type + pubseekoff(off_type __off, ios_base::seekdir __way, + ios_base::openmode __mode = ios_base::in | ios_base::out) + { return this->seekoff(__off, __way, __mode); } + + pos_type + pubseekpos(pos_type __sp, + ios_base::openmode __mode = ios_base::in | ios_base::out) + { return this->seekpos(__sp, __mode); } + + int + pubsync() { return this->sync(); } + //@} + + // [27.5.2.2.3] get area + /** + * @brief Looking ahead into the stream. + * @return The number of characters available. + * + * If a read position is available, returns the number of characters + * available for reading before the buffer must be refilled. + * Otherwise returns the derived @c showmanyc(). + */ + streamsize + in_avail() + { + const streamsize __ret = this->egptr() - this->gptr(); + return __ret ? __ret : this->showmanyc(); + } + + /** + * @brief Getting the next character. + * @return The next character, or eof. + * + * Calls @c sbumpc(), and if that function returns + * @c traits::eof(), so does this function. Otherwise, @c sgetc(). + */ + int_type + snextc() + { + int_type __ret = traits_type::eof(); + if (__builtin_expect(!traits_type::eq_int_type(this->sbumpc(), + __ret), true)) + __ret = this->sgetc(); + return __ret; + } + + /** + * @brief Getting the next character. + * @return The next character, or eof. + * + * If the input read position is available, returns that character + * and increments the read pointer, otherwise calls and returns + * @c uflow(). + */ + int_type + sbumpc() + { + int_type __ret; + if (__builtin_expect(this->gptr() < this->egptr(), true)) + { + __ret = traits_type::to_int_type(*this->gptr()); + this->gbump(1); + } + else + __ret = this->uflow(); + return __ret; + } + + /** + * @brief Getting the next character. + * @return The next character, or eof. + * + * If the input read position is available, returns that character, + * otherwise calls and returns @c underflow(). Does not move the + * read position after fetching the character. + */ + int_type + sgetc() + { + int_type __ret; + if (__builtin_expect(this->gptr() < this->egptr(), true)) + __ret = traits_type::to_int_type(*this->gptr()); + else + __ret = this->underflow(); + return __ret; + } + + /** + * @brief Entry point for xsgetn. + * @param s A buffer area. + * @param n A count. + * + * Returns xsgetn(s,n). The effect is to fill @a s[0] through + * @a s[n-1] with characters from the input sequence, if possible. + */ + streamsize + sgetn(char_type* __s, streamsize __n) + { return this->xsgetn(__s, __n); } + + // [27.5.2.2.4] putback + /** + * @brief Pushing characters back into the input stream. + * @param c The character to push back. + * @return The previous character, if possible. + * + * Similar to sungetc(), but @a c is pushed onto the stream instead + * of "the previous character". If successful, the next character + * fetched from the input stream will be @a c. + */ + int_type + sputbackc(char_type __c) + { + int_type __ret; + const bool __testpos = this->eback() < this->gptr(); + if (__builtin_expect(!__testpos || + !traits_type::eq(__c, this->gptr()[-1]), false)) + __ret = this->pbackfail(traits_type::to_int_type(__c)); + else + { + this->gbump(-1); + __ret = traits_type::to_int_type(*this->gptr()); + } + return __ret; + } + + /** + * @brief Moving backwards in the input stream. + * @return The previous character, if possible. + * + * If a putback position is available, this function decrements the + * input pointer and returns that character. Otherwise, calls and + * returns pbackfail(). The effect is to "unget" the last character + * "gotten". + */ + int_type + sungetc() + { + int_type __ret; + if (__builtin_expect(this->eback() < this->gptr(), true)) + { + this->gbump(-1); + __ret = traits_type::to_int_type(*this->gptr()); + } + else + __ret = this->pbackfail(); + return __ret; + } + + // [27.5.2.2.5] put area + /** + * @brief Entry point for all single-character output functions. + * @param c A character to output. + * @return @a c, if possible. + * + * One of two public output functions. + * + * If a write position is available for the output sequence (i.e., + * the buffer is not full), stores @a c in that position, increments + * the position, and returns @c traits::to_int_type(c). If a write + * position is not available, returns @c overflow(c). + */ + int_type + sputc(char_type __c) + { + int_type __ret; + if (__builtin_expect(this->pptr() < this->epptr(), true)) + { + *this->pptr() = __c; + this->pbump(1); + __ret = traits_type::to_int_type(__c); + } + else + __ret = this->overflow(traits_type::to_int_type(__c)); + return __ret; + } + + /** + * @brief Entry point for all single-character output functions. + * @param s A buffer read area. + * @param n A count. + * + * One of two public output functions. + * + * + * Returns xsputn(s,n). The effect is to write @a s[0] through + * @a s[n-1] to the output sequence, if possible. + */ + streamsize + sputn(const char_type* __s, streamsize __n) + { return this->xsputn(__s, __n); } + + protected: + /** + * @brief Base constructor. + * + * Only called from derived constructors, and sets up all the + * buffer data to zero, including the pointers described in the + * basic_streambuf class description. Note that, as a result, + * - the class starts with no read nor write positions available, + * - this is not an error + */ + basic_streambuf() + : _M_in_beg(0), _M_in_cur(0), _M_in_end(0), + _M_out_beg(0), _M_out_cur(0), _M_out_end(0), + _M_buf_locale(locale()) + { } + + // [27.5.2.3.1] get area access + //@{ + /** + * @brief Access to the get area. + * + * These functions are only available to other protected functions, + * including derived classes. + * + * - eback() returns the beginning pointer for the input sequence + * - gptr() returns the next pointer for the input sequence + * - egptr() returns the end pointer for the input sequence + */ + char_type* + eback() const { return _M_in_beg; } + + char_type* + gptr() const { return _M_in_cur; } + + char_type* + egptr() const { return _M_in_end; } + //@} + + /** + * @brief Moving the read position. + * @param n The delta by which to move. + * + * This just advances the read position without returning any data. + */ + void + gbump(int __n) { _M_in_cur += __n; } + + /** + * @brief Setting the three read area pointers. + * @param gbeg A pointer. + * @param gnext A pointer. + * @param gend A pointer. + * @post @a gbeg == @c eback(), @a gnext == @c gptr(), and + * @a gend == @c egptr() + */ + void + setg(char_type* __gbeg, char_type* __gnext, char_type* __gend) + { + _M_in_beg = __gbeg; + _M_in_cur = __gnext; + _M_in_end = __gend; + } + + // [27.5.2.3.2] put area access + //@{ + /** + * @brief Access to the put area. + * + * These functions are only available to other protected functions, + * including derived classes. + * + * - pbase() returns the beginning pointer for the output sequence + * - pptr() returns the next pointer for the output sequence + * - epptr() returns the end pointer for the output sequence + */ + char_type* + pbase() const { return _M_out_beg; } + + char_type* + pptr() const { return _M_out_cur; } + + char_type* + epptr() const { return _M_out_end; } + //@} + + /** + * @brief Moving the write position. + * @param n The delta by which to move. + * + * This just advances the write position without returning any data. + */ + void + pbump(int __n) { _M_out_cur += __n; } + + /** + * @brief Setting the three write area pointers. + * @param pbeg A pointer. + * @param pend A pointer. + * @post @a pbeg == @c pbase(), @a pbeg == @c pptr(), and + * @a pend == @c epptr() + */ + void + setp(char_type* __pbeg, char_type* __pend) + { + _M_out_beg = _M_out_cur = __pbeg; + _M_out_end = __pend; + } + + // [27.5.2.4] virtual functions + // [27.5.2.4.1] locales + /** + * @brief Changes translations. + * @param loc A new locale. + * + * Translations done during I/O which depend on the current locale + * are changed by this call. The standard adds, "Between invocations + * of this function a class derived from streambuf can safely cache + * results of calls to locale functions and to members of facets + * so obtained." + * + * @note Base class version does nothing. + */ + virtual void + imbue(const locale&) + { } + + // [27.5.2.4.2] buffer management and positioning + /** + * @brief Manipulates the buffer. + * + * Each derived class provides its own appropriate behavior. See + * the next-to-last paragraph of + * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25s02.html + * for more on this function. + * + * @note Base class version does nothing, returns @c this. + */ + virtual basic_streambuf<char_type,_Traits>* + setbuf(char_type*, streamsize) + { return this; } + + /** + * @brief Alters the stream positions. + * + * Each derived class provides its own appropriate behavior. + * @note Base class version does nothing, returns a @c pos_type + * that represents an invalid stream position. + */ + virtual pos_type + seekoff(off_type, ios_base::seekdir, + ios_base::openmode /*__mode*/ = ios_base::in | ios_base::out) + { return pos_type(off_type(-1)); } + + /** + * @brief Alters the stream positions. + * + * Each derived class provides its own appropriate behavior. + * @note Base class version does nothing, returns a @c pos_type + * that represents an invalid stream position. + */ + virtual pos_type + seekpos(pos_type, + ios_base::openmode /*__mode*/ = ios_base::in | ios_base::out) + { return pos_type(off_type(-1)); } + + /** + * @brief Synchronizes the buffer arrays with the controlled sequences. + * @return -1 on failure. + * + * Each derived class provides its own appropriate behavior, + * including the definition of "failure". + * @note Base class version does nothing, returns zero. + */ + virtual int + sync() { return 0; } + + // [27.5.2.4.3] get area + /** + * @brief Investigating the data available. + * @return An estimate of the number of characters available in the + * input sequence, or -1. + * + * "If it returns a positive value, then successive calls to + * @c underflow() will not return @c traits::eof() until at least that + * number of characters have been supplied. If @c showmanyc() + * returns -1, then calls to @c underflow() or @c uflow() will fail." + * [27.5.2.4.3]/1 + * + * @note Base class version does nothing, returns zero. + * @note The standard adds that "the intention is not only that the + * calls [to underflow or uflow] will not return @c eof() but + * that they will return "immediately". + * @note The standard adds that "the morphemes of @c showmanyc are + * "es-how-many-see", not "show-manic". + */ + virtual streamsize + showmanyc() { return 0; } + + /** + * @brief Multiple character extraction. + * @param s A buffer area. + * @param n Maximum number of characters to assign. + * @return The number of characters assigned. + * + * Fills @a s[0] through @a s[n-1] with characters from the input + * sequence, as if by @c sbumpc(). Stops when either @a n characters + * have been copied, or when @c traits::eof() would be copied. + * + * It is expected that derived classes provide a more efficient + * implementation by overriding this definition. + */ + virtual streamsize + xsgetn(char_type* __s, streamsize __n); + + /** + * @brief Fetches more data from the controlled sequence. + * @return The first character from the <em>pending sequence</em>. + * + * Informally, this function is called when the input buffer is + * exhausted (or does not exist, as buffering need not actually be + * done). If a buffer exists, it is "refilled". In either case, the + * next available character is returned, or @c traits::eof() to + * indicate a null pending sequence. + * + * For a formal definition of the pending sequence, see a good text + * such as Langer & Kreft, or [27.5.2.4.3]/7-14. + * + * A functioning input streambuf can be created by overriding only + * this function (no buffer area will be used). For an example, see + * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25.html + * + * @note Base class version does nothing, returns eof(). + */ + virtual int_type + underflow() + { return traits_type::eof(); } + + /** + * @brief Fetches more data from the controlled sequence. + * @return The first character from the <em>pending sequence</em>. + * + * Informally, this function does the same thing as @c underflow(), + * and in fact is required to call that function. It also returns + * the new character, like @c underflow() does. However, this + * function also moves the read position forward by one. + */ + virtual int_type + uflow() + { + int_type __ret = traits_type::eof(); + const bool __testeof = traits_type::eq_int_type(this->underflow(), + __ret); + if (!__testeof) + { + __ret = traits_type::to_int_type(*this->gptr()); + this->gbump(1); + } + return __ret; + } + + // [27.5.2.4.4] putback + /** + * @brief Tries to back up the input sequence. + * @param c The character to be inserted back into the sequence. + * @return eof() on failure, "some other value" on success + * @post The constraints of @c gptr(), @c eback(), and @c pptr() + * are the same as for @c underflow(). + * + * @note Base class version does nothing, returns eof(). + */ + virtual int_type + pbackfail(int_type /* __c */ = traits_type::eof()) + { return traits_type::eof(); } + + // Put area: + /** + * @brief Multiple character insertion. + * @param s A buffer area. + * @param n Maximum number of characters to write. + * @return The number of characters written. + * + * Writes @a s[0] through @a s[n-1] to the output sequence, as if + * by @c sputc(). Stops when either @a n characters have been + * copied, or when @c sputc() would return @c traits::eof(). + * + * It is expected that derived classes provide a more efficient + * implementation by overriding this definition. + */ + virtual streamsize + xsputn(const char_type* __s, streamsize __n); + + /** + * @brief Consumes data from the buffer; writes to the + * controlled sequence. + * @param c An additional character to consume. + * @return eof() to indicate failure, something else (usually + * @a c, or not_eof()) + * + * Informally, this function is called when the output buffer is full + * (or does not exist, as buffering need not actually be done). If a + * buffer exists, it is "consumed", with "some effect" on the + * controlled sequence. (Typically, the buffer is written out to the + * sequence verbatim.) In either case, the character @a c is also + * written out, if @a c is not @c eof(). + * + * For a formal definition of this function, see a good text + * such as Langer & Kreft, or [27.5.2.4.5]/3-7. + * + * A functioning output streambuf can be created by overriding only + * this function (no buffer area will be used). + * + * @note Base class version does nothing, returns eof(). + */ + virtual int_type + overflow(int_type /* __c */ = traits_type::eof()) + { return traits_type::eof(); } + +#if _GLIBCXX_DEPRECATED + // Annex D.6 + public: + /** + * @brief Tosses a character. + * + * Advances the read pointer, ignoring the character that would have + * been read. + * + * See http://gcc.gnu.org/ml/libstdc++/2002-05/msg00168.html + */ + void + stossc() + { + if (this->gptr() < this->egptr()) + this->gbump(1); + else + this->uflow(); + } +#endif + + private: + // _GLIBCXX_RESOLVE_LIB_DEFECTS + // Side effect of DR 50. + basic_streambuf(const __streambuf_type& __sb) + : _M_in_beg(__sb._M_in_beg), _M_in_cur(__sb._M_in_cur), + _M_in_end(__sb._M_in_end), _M_out_beg(__sb._M_out_beg), + _M_out_cur(__sb._M_out_cur), _M_out_end(__sb._M_out_cur), + _M_buf_locale(__sb._M_buf_locale) + { } + + __streambuf_type& + operator=(const __streambuf_type&) { return *this; }; + }; + + // Explicit specialization declarations, defined in src/streambuf.cc. + template<> + streamsize + __copy_streambufs_eof(basic_streambuf<char>* __sbin, + basic_streambuf<char>* __sbout, bool& __ineof); +#ifdef _GLIBCXX_USE_WCHAR_T + template<> + streamsize + __copy_streambufs_eof(basic_streambuf<wchar_t>* __sbin, + basic_streambuf<wchar_t>* __sbout, bool& __ineof); +#endif + +_GLIBCXX_END_NAMESPACE + +#ifndef _GLIBCXX_EXPORT_TEMPLATE +# include <bits/streambuf.tcc> +#endif + +#endif /* _GLIBCXX_STREAMBUF */ |