sstream.tcc
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// String based streams -*- C++ -*-
// Copyright (C) 1997-2021 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 bits/sstream.tcc
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{sstream}
*/
//
// ISO C++ 14882: 27.7 String-based streams
//
#ifndef _SSTREAM_TCC
#define _SSTREAM_TCC 1
#pragma GCC system_header
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
template <class _CharT, class _Traits, class _Alloc>
typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
basic_stringbuf<_CharT, _Traits, _Alloc>::
pbackfail(int_type __c)
{
int_type __ret = traits_type::eof();
if (this->eback() < this->gptr())
{
// Try to put back __c into input sequence in one of three ways.
// Order these tests done in is unspecified by the standard.
const bool __testeof = traits_type::eq_int_type(__c, __ret);
if (!__testeof)
{
const bool __testeq = traits_type::eq(traits_type::
to_char_type(__c),
this->gptr()[-1]);
const bool __testout = this->_M_mode & ios_base::out;
if (__testeq || __testout)
{
this->gbump(-1);
if (!__testeq)
*this->gptr() = traits_type::to_char_type(__c);
__ret = __c;
}
}
else
{
this->gbump(-1);
__ret = traits_type::not_eof(__c);
}
}
return __ret;
}
template <class _CharT, class _Traits, class _Alloc>
typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
basic_stringbuf<_CharT, _Traits, _Alloc>::
overflow(int_type __c)
{
const bool __testout = this->_M_mode & ios_base::out;
if (__builtin_expect(!__testout, false))
return traits_type::eof();
const bool __testeof = traits_type::eq_int_type(__c, traits_type::eof());
if (__builtin_expect(__testeof, false))
return traits_type::not_eof(__c);
const __size_type __capacity = _M_string.capacity();
#if _GLIBCXX_USE_CXX11_ABI
if (size_t(this->epptr() - this->pbase()) < __capacity)
{
// There is additional capacity in _M_string that can be used.
char_type* __base = const_cast<char_type*>(_M_string.data());
_M_pbump(__base, __base + __capacity, this->pptr() - this->pbase());
if (_M_mode & ios_base::in)
{
const __size_type __nget = this->gptr() - this->eback();
const __size_type __eget = this->egptr() - this->eback();
this->setg(__base, __base + __nget, __base + __eget + 1);
}
*this->pptr() = traits_type::to_char_type(__c);
this->pbump(1);
return __c;
}
#endif
const __size_type __max_size = _M_string.max_size();
const bool __testput = this->pptr() < this->epptr();
if (__builtin_expect(!__testput && __capacity == __max_size, false))
return traits_type::eof();
// Try to append __c into output sequence in one of two ways.
// Order these tests done in is unspecified by the standard.
const char_type __conv = traits_type::to_char_type(__c);
if (!__testput)
{
// NB: Start ostringstream buffers at 512 chars. This is an
// experimental value (pronounced "arbitrary" in some of the
// hipper English-speaking countries), and can be changed to
// suit particular needs.
//
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 169. Bad efficiency of overflow() mandated
// 432. stringbuf::overflow() makes only one write position
// available
const __size_type __opt_len = std::max(__size_type(2 * __capacity),
__size_type(512));
const __size_type __len = std::min(__opt_len, __max_size);
__string_type __tmp(_M_string.get_allocator());
__tmp.reserve(__len);
if (this->pbase())
__tmp.assign(this->pbase(), this->epptr() - this->pbase());
__tmp.push_back(__conv);
_M_string.swap(__tmp);
_M_sync(const_cast<char_type*>(_M_string.data()),
this->gptr() - this->eback(), this->pptr() - this->pbase());
}
else
*this->pptr() = __conv;
this->pbump(1);
return __c;
}
template <class _CharT, class _Traits, class _Alloc>
typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
basic_stringbuf<_CharT, _Traits, _Alloc>::
underflow()
{
int_type __ret = traits_type::eof();
const bool __testin = this->_M_mode & ios_base::in;
if (__testin)
{
// Update egptr() to match the actual string end.
_M_update_egptr();
if (this->gptr() < this->egptr())
__ret = traits_type::to_int_type(*this->gptr());
}
return __ret;
}
template <class _CharT, class _Traits, class _Alloc>
typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
basic_stringbuf<_CharT, _Traits, _Alloc>::
seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode)
{
pos_type __ret = pos_type(off_type(-1));
bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
const bool __testboth = __testin && __testout && __way != ios_base::cur;
__testin &= !(__mode & ios_base::out);
__testout &= !(__mode & ios_base::in);
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// 453. basic_stringbuf::seekoff need not always fail for an empty stream.
const char_type* __beg = __testin ? this->eback() : this->pbase();
if ((__beg || !__off) && (__testin || __testout || __testboth))
{
_M_update_egptr();
off_type __newoffi = __off;
off_type __newoffo = __newoffi;
if (__way == ios_base::cur)
{
__newoffi += this->gptr() - __beg;
__newoffo += this->pptr() - __beg;
}
else if (__way == ios_base::end)
__newoffo = __newoffi += this->egptr() - __beg;
if ((__testin || __testboth)
&& __newoffi >= 0
&& this->egptr() - __beg >= __newoffi)
{
this->setg(this->eback(), this->eback() + __newoffi,
this->egptr());
__ret = pos_type(__newoffi);
}
if ((__testout || __testboth)
&& __newoffo >= 0
&& this->egptr() - __beg >= __newoffo)
{
_M_pbump(this->pbase(), this->epptr(), __newoffo);
__ret = pos_type(__newoffo);
}
}
return __ret;
}
template <class _CharT, class _Traits, class _Alloc>
typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
basic_stringbuf<_CharT, _Traits, _Alloc>::
seekpos(pos_type __sp, ios_base::openmode __mode)
{
pos_type __ret = pos_type(off_type(-1));
const bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
const bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
const char_type* __beg = __testin ? this->eback() : this->pbase();
if ((__beg || !off_type(__sp)) && (__testin || __testout))
{
_M_update_egptr();
const off_type __pos(__sp);
const bool __testpos = (0 <= __pos
&& __pos <= this->egptr() - __beg);
if (__testpos)
{
if (__testin)
this->setg(this->eback(), this->eback() + __pos,
this->egptr());
if (__testout)
_M_pbump(this->pbase(), this->epptr(), __pos);
__ret = __sp;
}
}
return __ret;
}
template <class _CharT, class _Traits, class _Alloc>
void
basic_stringbuf<_CharT, _Traits, _Alloc>::
_M_sync(char_type* __base, __size_type __i, __size_type __o)
{
const bool __testin = _M_mode & ios_base::in;
const bool __testout = _M_mode & ios_base::out;
char_type* __endg = __base + _M_string.size();
char_type* __endp = __base + _M_string.capacity();
if (__base != _M_string.data())
{
// setbuf: __i == size of buffer area (_M_string.size() == 0).
__endg += __i;
__i = 0;
__endp = __endg;
}
if (__testin)
this->setg(__base, __base + __i, __endg);
if (__testout)
{
_M_pbump(__base, __endp, __o);
// egptr() always tracks the string end. When !__testin,
// for the correct functioning of the streambuf inlines
// the other get area pointers are identical.
if (!__testin)
this->setg(__endg, __endg, __endg);
}
}
template <class _CharT, class _Traits, class _Alloc>
void
basic_stringbuf<_CharT, _Traits, _Alloc>::
_M_pbump(char_type* __pbeg, char_type* __pend, off_type __off)
{
this->setp(__pbeg, __pend);
while (__off > __gnu_cxx::__numeric_traits<int>::__max)
{
this->pbump(__gnu_cxx::__numeric_traits<int>::__max);
__off -= __gnu_cxx::__numeric_traits<int>::__max;
}
this->pbump(__off);
}
// Inhibit implicit instantiations for required instantiations,
// which are defined via explicit instantiations elsewhere.
#if _GLIBCXX_EXTERN_TEMPLATE
extern template class basic_stringbuf<char>;
extern template class basic_istringstream<char>;
extern template class basic_ostringstream<char>;
extern template class basic_stringstream<char>;
#ifdef _GLIBCXX_USE_WCHAR_T
extern template class basic_stringbuf<wchar_t>;
extern template class basic_istringstream<wchar_t>;
extern template class basic_ostringstream<wchar_t>;
extern template class basic_stringstream<wchar_t>;
#endif
#endif
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#endif
std::max
constexpr const _Tp & max(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:254
std::min
constexpr const _Tp & min(const _Tp &, const _Tp &)
This does what you think it does.
Definition: stl_algobase.h:230
std
ISO C++ entities toplevel namespace is std.
__gnu_debug::__base
constexpr _Iterator __base(_Iterator __it)
Definition: helper_functions.h:315
std::basic_stringbuf
The actual work of input and output (for std::string).
Definition: sstream:73
std::basic_stringbuf::underflow
virtual int_type underflow()
Fetches more data from the controlled sequence.
Definition: sstream.tcc:150
std::basic_stringbuf::seekpos
virtual pos_type seekpos(pos_type __sp, ios_base::openmode __mode=ios_base::in|ios_base::out)
Alters the stream positions.
Definition: sstream.tcc:216
std::basic_stringbuf::seekoff
virtual pos_type seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode=ios_base::in|ios_base::out)
Alters the stream positions.
Definition: sstream.tcc:168
std::basic_stringbuf::overflow
virtual int_type overflow(int_type __c=traits_type::eof())
Consumes data from the buffer; writes to the controlled sequence.
Definition: sstream.tcc:80
std::basic_stringbuf::pbackfail
virtual int_type pbackfail(int_type __c=traits_type::eof())
Tries to back up the input sequence.
Definition: sstream.tcc:46
std::basic_string< char_type, _Traits, _Alloc >
std::basic_string::push_back
void push_back(_CharT __c)
Append a single character.
Definition: basic_string.h:4381
std::basic_string::reserve
void reserve(size_type __res_arg)
Attempt to preallocate enough memory for specified number of characters.
Definition: basic_string.tcc:933
std::basic_string::assign
basic_string & assign(const basic_string &__str)
Set value to contents of another string.
Definition: basic_string.tcc:674
std::ios_base::cur
static const seekdir cur
Request a seek relative to the current position within the sequence.
Definition: ios_base.h:485
std::ios_base::end
static const seekdir end
Request a seek relative to the current end of the sequence.
Definition: ios_base.h:488
std::ios_base::in
static const openmode in
Open for input. Default for ifstream and fstream.
Definition: ios_base.h:461
std::ios_base::out
static const openmode out
Open for output. Default for ofstream and fstream.
Definition: ios_base.h:464