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gcc/libstdc++-v3/include/std/streambuf
Jonathan Wakely eef9bf4ca8 libstdc++: Add deprecated attributes to old iostream members 
Back in 2017 I removed these prehistoric members (which were deprecated
since C++98) for C++17 mode. But I didn't add deprecated attributes to
most of them, so users didn't get any warning they would be going away.
Apparently some poor souls do actually use some of these names, and so
now that GCC 11 defaults to -std=gnu++17 some code has stopped
compiling.

This adds deprecated attributes to them, so that C++98/03/11/14 code
will get a warning if it uses them. I'll also backport this to the
release branches so that users can find out about the deprecation before
they start using C++17.

In order to give deprecated warnings even in C++98 mode this patch makes
_GLIBCXX_DEPRECATED work even for C++98, adds _GLIBCXX11_DEPRECATED for
the old meaning of _GLIBCXX_DEPRECATED, and adds new macros such as
_GLIBCXX_DEPRECATED_SUGGEST for suggesting alternatives to deprecated
features.

libstdc++-v3/ChangeLog:

	* include/bits/c++config (_GLIBCXX_DEPRECATED): Define for all
	standard modes.
	(_GLIBCXX_DEPRECATED_SUGGEST): New macro for "use 'foo' instead"
	message in deprecated warnings.
	(_GLIBCXX11_DEPRECATED, _GLIBCXX11_DEPRECATED_SUGGEST): New
	macros for marking features derpecated in C++11.
	(_GLIBCXX17_DEPRECATED_SUGGEST, _GLIBCXX20_DEPRECATED_SUGGEST):
	New macros.
	* include/backward/auto_ptr.h (auto_ptr_ref, auto_ptr<void>):
	Use _GLIBCXX11_DEPRECATED instead of _GLIBCXX_DEPRECATED.
	(auto_ptr): Use _GLIBCXX11_DEPRECATED_SUGGEST.
	* include/backward/binders.h (binder1st, binder2nd): Likewise.
	* include/bits/ios_base.h (io_state, open_mode, seek_dir)
	(streampos, streamoff): Use _GLIBCXX_DEPRECATED_SUGGEST.
	* include/std/streambuf (stossc): Replace C++11 attribute
	with _GLIBCXX_DEPRECATED_SUGGEST.
	* include/std/type_traits (__is_nullptr_t): Use
	_GLIBCXX_DEPRECATED_SUGGEST instead of _GLIBCXX_DEPRECATED.
	* testsuite/27_io/types/1.cc: Check for deprecated warnings.
	Also check for io_state, open_mode and seek_dir typedefs.
2020-08-19 12:13:23 +01:00

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// Stream buffer classes -*- 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/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>
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
#define _IsUnused __attribute__ ((__unused__))
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).
* @ingroup io
*
* @tparam _CharT Type of character stream.
* @tparam _Traits Traits for character type, defaults to
* char_traits<_CharT>.
*
* 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 <em>the stream position</em> 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 dependent 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<>(basic_streambuf*, basic_streambuf*, 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 _Distance>
friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value,
void>::__type
advance(istreambuf_iterator<_CharT2>&, _Distance);
friend void __istream_extract(istream&, char*, streamsize);
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.
*/
basic_streambuf*
pubsetbuf(char_type* __s, streamsize __n)
{ return this->setbuf(__s, __n); }
/**
* @brief Alters the stream position.
* @param __off Offset.
* @param __way Value for ios_base::seekdir.
* @param __mode Value for ios_base::openmode.
*
* Calls virtual seekoff function.
*/
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); }
/**
* @brief Alters the stream position.
* @param __sp Position
* @param __mode Value for ios_base::openmode.
*
* Calls virtual seekpos function.
*/
pos_type
pubseekpos(pos_type __sp,
ios_base::openmode __mode = ios_base::in | ios_base::out)
{ return this->seekpos(__sp, __mode); }
/**
* @brief Calls virtual sync function.
*/
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 <em>the previous character.</em> 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 @a unget
* the last character @a 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,
* <em>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.</em>
*
* @note Base class version does nothing.
*/
virtual void
imbue(const locale& __loc _IsUnused)
{ }
// [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
* https://gcc.gnu.org/onlinedocs/libstdc++/manual/streambufs.html#io.streambuf.buffering
* 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 @a 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.
*
* <em>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.</em> [27.5.2.4.3]/1
*
* @note Base class version does nothing, returns zero.
* @note The standard adds that <em>the intention is not only that the
* calls [to underflow or uflow] will not return @c eof() but
* that they will return immediately.</em>
* @note The standard adds that <em>the morphemes of @c showmanyc are
* @b es-how-many-see, not @b show-manic.</em>
*/
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 @a 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
* https://gcc.gnu.org/onlinedocs/libstdc++/manual/streambufs.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, <em>some other value</em> 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 _IsUnused = 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 @a consumed, with
* <em>some effect</em> 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 _IsUnused = traits_type::eof())
{ return traits_type::eof(); }
#if _GLIBCXX_USE_DEPRECATED && __cplusplus <= 201402L
// Annex D.6 (removed in C++17)
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
*/
_GLIBCXX_DEPRECATED_SUGGEST("std::basic_streambuf::sbumpc")
void
stossc()
{
if (this->gptr() < this->egptr())
this->gbump(1);
else
this->uflow();
}
#endif
// Also used by specializations for char and wchar_t in src.
void
__safe_gbump(streamsize __n) { _M_in_cur += __n; }
void
__safe_pbump(streamsize __n) { _M_out_cur += __n; }
#if __cplusplus < 201103L
private:
#else
protected:
#endif
basic_streambuf(const basic_streambuf&);
basic_streambuf&
operator=(const basic_streambuf&);
#if __cplusplus >= 201103L
void
swap(basic_streambuf& __sb)
{
std::swap(_M_in_beg, __sb._M_in_beg);
std::swap(_M_in_cur, __sb._M_in_cur);
std::swap(_M_in_end, __sb._M_in_end);
std::swap(_M_out_beg, __sb._M_out_beg);
std::swap(_M_out_cur, __sb._M_out_cur);
std::swap(_M_out_end, __sb._M_out_end);
std::swap(_M_buf_locale, __sb._M_buf_locale);
}
#endif
};
#if __cplusplus >= 201103L
template<typename _CharT, typename _Traits>
std::basic_streambuf<_CharT, _Traits>::
basic_streambuf(const basic_streambuf&) = default;
template<typename _CharT, typename _Traits>
std::basic_streambuf<_CharT, _Traits>&
std::basic_streambuf<_CharT, _Traits>::
operator=(const basic_streambuf&) = default;
#endif
// 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
#undef _IsUnused
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#include <bits/streambuf.tcc>
#endif /* _GLIBCXX_STREAMBUF */
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