gcc/libstdc++-v3/include/bits/sstream.tcc
Paolo Carlini 74843551df sstream.tcc (overflow): Instead of calling str()...
2003-05-01  Paolo Carlini  <pcarlini@unitus.it>

	* include/bits/sstream.tcc (overflow): Instead of calling
	str(), then _M_string.reserve, thus copying the contents
	of the current buffer two times, just copy the latter in
	a temporary, then use the 'swap trick'.

From-SVN: r66358
2003-05-02 00:14:49 +00:00

243 lines
8.0 KiB
C++

// String based streams -*- C++ -*-
// Copyright (C) 1997, 1998, 1999, 2001, 2002, 2003
// 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: 27.7 String-based streams
//
#ifndef _CPP_BITS_SSTREAM_TCC
#define _CPP_BITS_SSTREAM_TCC 1
#pragma GCC system_header
#include <sstream>
namespace std
{
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();
const bool __testeof = traits_type::eq_int_type(__c,
traits_type::eof());
const bool __testpos = this->_M_in_beg < this->_M_in_cur;
// Try to put back __c into input sequence in one of three ways.
// Order these tests done in is unspecified by the standard.
if (__testpos)
{
const bool __testeq = traits_type::eq(traits_type::to_char_type(__c),
this->_M_in_cur[-1]);
--this->_M_in_cur;
if (!__testeof && __testeq)
__ret = __c;
else if (__testeof)
__ret = traits_type::not_eof(__c);
else
{
*this->_M_in_cur = traits_type::to_char_type(__c);
__ret = __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);
// 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.
__size_type __len = std::max(__size_type(_M_string.capacity() + 1),
__size_type(512));
const bool __testput = this->_M_out_cur < this->_M_out_end;
if (__builtin_expect(!__testput && __len > _M_string.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.
if (!__testput)
{
// In virtue of DR 169 (TC) we are allowed to grow more than
// one char. That's easy to implement thanks to the exponential
// growth policy builtin into basic_string.
__string_type __tmp;
__tmp.reserve(__len);
__tmp.assign(_M_string.data(),
this->_M_out_end - this->_M_out_beg);
_M_string.swap(__tmp);
// Just to be sure...
_M_string.reserve(__len);
_M_really_sync(const_cast<char_type*>(_M_string.data()),
this->_M_in_cur - this->_M_in_beg,
this->_M_out_cur - this->_M_out_beg);
}
return this->sputc(traits_type::to_char_type(__c));
}
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);
if (_M_string.capacity() && (__testin || __testout || __testboth))
{
char_type* __beg = __testin ? this->_M_in_beg : this->_M_out_beg;
char_type* __curi = NULL;
char_type* __curo = NULL;
char_type* __endi = NULL;
char_type* __endo = NULL;
if (__testin || __testboth)
{
__curi = this->_M_in_cur;
__endi = this->_M_in_end;
}
if (__testout || __testboth)
{
__curo = this->_M_out_cur;
// Due to the resolution of DR169, ios_base::end
// is this->_M_out_lim, not _M_out_end.
__endo = this->_M_out_lim;
}
off_type __newoffi = 0;
off_type __newoffo = 0;
if (__way == ios_base::cur)
{
__newoffi = __curi - __beg;
__newoffo = __curo - __beg;
}
else if (__way == ios_base::end)
{
__newoffi = __endi - __beg;
__newoffo = __endo - __beg;
}
if ((__testin || __testboth)
&& __newoffi + __off >= 0 && __endi - __beg >= __newoffi + __off)
{
this->_M_in_cur = __beg + __newoffi + __off;
__ret = pos_type(__newoffi);
}
if ((__testout || __testboth)
&& __newoffo + __off >= 0 && __endo - __beg >= __newoffo + __off)
{
_M_move_out_cur(__newoffo + __off - (this->_M_out_cur - __beg));
__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));
if (_M_string.capacity())
{
off_type __pos = __sp; // Use streamoff operator to do conversion.
char_type* __beg = NULL;
char_type* __end = NULL;
const bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
const bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
// NB: Ordered.
bool __testposi = false;
bool __testposo = false;
if (__testin)
{
__beg = this->_M_in_beg;
__end = this->_M_in_end;
if (0 <= __pos && __pos <= __end - __beg)
__testposi = true;
}
if (__testout)
{
__beg = this->_M_out_beg;
__end = this->_M_out_end;
if (0 <= __pos && __pos <= __end - __beg)
__testposo = true;
}
if (__testposi || __testposo)
{
if (__testposi)
this->_M_in_cur = this->_M_in_beg + __pos;
if (__testposo)
_M_move_out_cur((__pos) - (this->_M_out_cur - __beg));
__ret = pos_type(off_type(__pos));
}
}
return __ret;
}
// Inhibit implicit instantiations for required instantiations,
// which are defined via explicit instantiations elsewhere.
// NB: This syntax is a GNU extension.
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 _GLIBCPP_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
} // namespace std
#endif