1    	// String based streams -*- C++ -*-
2    	
3    	// Copyright (C) 1997-2017 Free Software Foundation, Inc.
4    	//
5    	// This file is part of the GNU ISO C++ Library.  This library is free
6    	// software; you can redistribute it and/or modify it under the
7    	// terms of the GNU General Public License as published by the
8    	// Free Software Foundation; either version 3, or (at your option)
9    	// any later version.
10   	
11   	// This library is distributed in the hope that it will be useful,
12   	// but WITHOUT ANY WARRANTY; without even the implied warranty of
13   	// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14   	// GNU General Public License for more details.
15   	
16   	// Under Section 7 of GPL version 3, you are granted additional
17   	// permissions described in the GCC Runtime Library Exception, version
18   	// 3.1, as published by the Free Software Foundation.
19   	
20   	// You should have received a copy of the GNU General Public License and
21   	// a copy of the GCC Runtime Library Exception along with this program;
22   	// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23   	// <http://www.gnu.org/licenses/>.
24   	
25   	/** @file bits/sstream.tcc
26   	 *  This is an internal header file, included by other library headers.
27   	 *  Do not attempt to use it directly. @headername{sstream}
28   	 */
29   	
30   	//
31   	// ISO C++ 14882: 27.7  String-based streams
32   	//
33   	
34   	#ifndef _SSTREAM_TCC
35   	#define _SSTREAM_TCC 1
36   	
37   	#pragma GCC system_header
38   	
39   	namespace std _GLIBCXX_VISIBILITY(default)
40   	{
41   	_GLIBCXX_BEGIN_NAMESPACE_VERSION
42   	
43   	  template <class _CharT, class _Traits, class _Alloc>
44   	    typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
45   	    basic_stringbuf<_CharT, _Traits, _Alloc>::
46   	    pbackfail(int_type __c)
47   	    {
48   	      int_type __ret = traits_type::eof();
49   	      if (this->eback() < this->gptr())
50   		{
51   		  // Try to put back __c into input sequence in one of three ways.
52   		  // Order these tests done in is unspecified by the standard.
53   		  const bool __testeof = traits_type::eq_int_type(__c, __ret);
54   		  if (!__testeof)
55   		    {
56   		      const bool __testeq = traits_type::eq(traits_type::
57   							    to_char_type(__c),
58   							    this->gptr()[-1]);	  
59   		      const bool __testout = this->_M_mode & ios_base::out;
60   		      if (__testeq || __testout)
61   			{
62   			  this->gbump(-1);
63   			  if (!__testeq)
64   			    *this->gptr() = traits_type::to_char_type(__c);
65   			  __ret = __c;
66   			}
67   		    }
68   		  else
69   		    {
70   		      this->gbump(-1);
71   		      __ret = traits_type::not_eof(__c);
72   		    }
73   		}
74   	      return __ret;
75   	    }
76   	
77   	  template <class _CharT, class _Traits, class _Alloc>
78   	    typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
79   	    basic_stringbuf<_CharT, _Traits, _Alloc>::
80   	    overflow(int_type __c)
81   	    {
82   	      const bool __testout = this->_M_mode & ios_base::out;
83   	      if (__builtin_expect(!__testout, false))
84   		return traits_type::eof();
85   	
86   	      const bool __testeof = traits_type::eq_int_type(__c, traits_type::eof());
87   	      if (__builtin_expect(__testeof, false))
88   		return traits_type::not_eof(__c);
89   	
90   	      const __size_type __capacity = _M_string.capacity();
91   	
92   	#if _GLIBCXX_USE_CXX11_ABI
93   	      if ((this->epptr() - this->pbase()) < __capacity)
94   		{
95   		  // There is additional capacity in _M_string that can be used.
96   		  char_type* __base = const_cast<char_type*>(_M_string.data());
97   		  _M_pbump(__base, __base + __capacity, this->pptr() - this->pbase());
98   		  if (_M_mode & ios_base::in)
99   		    {
100  		      const __size_type __nget = this->gptr() - this->eback();
101  		      const __size_type __eget = this->egptr() - this->eback();
102  		      this->setg(__base, __base + __nget, __base + __eget + 1);
103  		    }
104  		  *this->pptr() = traits_type::to_char_type(__c);
105  		  this->pbump(1);
106  		  return __c;
107  		}
108  	#endif
109  	
110  	      const __size_type __max_size = _M_string.max_size();
111  	      const bool __testput = this->pptr() < this->epptr();
112  	      if (__builtin_expect(!__testput && __capacity == __max_size, false))
113  		return traits_type::eof();
114  	
115  	      // Try to append __c into output sequence in one of two ways.
116  	      // Order these tests done in is unspecified by the standard.
117  	      const char_type __conv = traits_type::to_char_type(__c);
118  	      if (!__testput)
119  		{
120  		  // NB: Start ostringstream buffers at 512 chars.  This is an
121  		  // experimental value (pronounced "arbitrary" in some of the
122  		  // hipper English-speaking countries), and can be changed to
123  		  // suit particular needs.
124  		  //
125  		  // _GLIBCXX_RESOLVE_LIB_DEFECTS
126  		  // 169. Bad efficiency of overflow() mandated
127  		  // 432. stringbuf::overflow() makes only one write position
128  		  //      available
129  		  const __size_type __opt_len = std::max(__size_type(2 * __capacity),
130  							 __size_type(512));
131  		  const __size_type __len = std::min(__opt_len, __max_size);
132  		  __string_type __tmp;
133  		  __tmp.reserve(__len);
134  		  if (this->pbase())
135  		    __tmp.assign(this->pbase(), this->epptr() - this->pbase());
136  		  __tmp.push_back(__conv);
137  		  _M_string.swap(__tmp);
138  		  _M_sync(const_cast<char_type*>(_M_string.data()),
139  			  this->gptr() - this->eback(), this->pptr() - this->pbase());
140  		}
141  	      else
142  		*this->pptr() = __conv;
143  	      this->pbump(1);
144  	      return __c;
145  	    }
146  	
147  	  template <class _CharT, class _Traits, class _Alloc>
148  	    typename basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
149  	    basic_stringbuf<_CharT, _Traits, _Alloc>::
150  	    underflow()
151  	    {
152  	      int_type __ret = traits_type::eof();
153  	      const bool __testin = this->_M_mode & ios_base::in;
154  	      if (__testin)
155  		{
156  		  // Update egptr() to match the actual string end.
157  		  _M_update_egptr();
158  	
159  		  if (this->gptr() < this->egptr())
160  		    __ret = traits_type::to_int_type(*this->gptr());
161  		}
162  	      return __ret;
163  	    }
164  	
165  	  template <class _CharT, class _Traits, class _Alloc>
166  	    typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
167  	    basic_stringbuf<_CharT, _Traits, _Alloc>::
168  	    seekoff(off_type __off, ios_base::seekdir __way, ios_base::openmode __mode)
169  	    {
170  	      pos_type __ret =  pos_type(off_type(-1));
171  	      bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
172  	      bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
173  	      const bool __testboth = __testin && __testout && __way != ios_base::cur;
174  	      __testin &= !(__mode & ios_base::out);
175  	      __testout &= !(__mode & ios_base::in);
176  	
177  	      // _GLIBCXX_RESOLVE_LIB_DEFECTS
178  	      // 453. basic_stringbuf::seekoff need not always fail for an empty stream.
179  	      const char_type* __beg = __testin ? this->eback() : this->pbase();
180  	      if ((__beg || !__off) && (__testin || __testout || __testboth))
181  		{
182  		  _M_update_egptr();
183  	
184  		  off_type __newoffi = __off;
185  		  off_type __newoffo = __newoffi;
186  		  if (__way == ios_base::cur)
187  		    {
188  		      __newoffi += this->gptr() - __beg;
189  		      __newoffo += this->pptr() - __beg;
190  		    }
191  		  else if (__way == ios_base::end)
192  		    __newoffo = __newoffi += this->egptr() - __beg;
193  	
194  		  if ((__testin || __testboth)
195  		      && __newoffi >= 0
196  		      && this->egptr() - __beg >= __newoffi)
197  		    {
198  		      this->setg(this->eback(), this->eback() + __newoffi,
199  				 this->egptr());
200  		      __ret = pos_type(__newoffi);
201  		    }
202  		  if ((__testout || __testboth)
203  		      && __newoffo >= 0
204  		      && this->egptr() - __beg >= __newoffo)
205  		    {
206  		      _M_pbump(this->pbase(), this->epptr(), __newoffo);
207  		      __ret = pos_type(__newoffo);
208  		    }
209  		}
210  	      return __ret;
211  	    }
212  	
213  	  template <class _CharT, class _Traits, class _Alloc>
214  	    typename basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
215  	    basic_stringbuf<_CharT, _Traits, _Alloc>::
216  	    seekpos(pos_type __sp, ios_base::openmode __mode)
217  	    {
218  	      pos_type __ret =  pos_type(off_type(-1));
219  	      const bool __testin = (ios_base::in & this->_M_mode & __mode) != 0;
220  	      const bool __testout = (ios_base::out & this->_M_mode & __mode) != 0;
221  	
222  	      const char_type* __beg = __testin ? this->eback() : this->pbase();
223  	      if ((__beg || !off_type(__sp)) && (__testin || __testout))
224  		{
225  		  _M_update_egptr();
226  	
227  		  const off_type __pos(__sp);
228  		  const bool __testpos = (0 <= __pos
229  					  && __pos <= this->egptr() - __beg);
230  		  if (__testpos)
231  		    {
232  		      if (__testin)
233  			this->setg(this->eback(), this->eback() + __pos,
234  				   this->egptr());
235  		      if (__testout)
236  			_M_pbump(this->pbase(), this->epptr(), __pos);
237  		      __ret = __sp;
238  		    }
239  		}
240  	      return __ret;
241  	    }
242  	
243  	  template <class _CharT, class _Traits, class _Alloc>
244  	    void
245  	    basic_stringbuf<_CharT, _Traits, _Alloc>::
246  	    _M_sync(char_type* __base, __size_type __i, __size_type __o)
247  	    {
248  	      const bool __testin = _M_mode & ios_base::in;
249  	      const bool __testout = _M_mode & ios_base::out;
250  	      char_type* __endg = __base + _M_string.size();
251  	      char_type* __endp = __base + _M_string.capacity();
252  	
253  	      if (__base != _M_string.data())
254  		{
255  		  // setbuf: __i == size of buffer area (_M_string.size() == 0).
256  		  __endg += __i;
257  		  __i = 0;
258  		  __endp = __endg;
259  		}
260  	
261  	      if (__testin)
262  		this->setg(__base, __base + __i, __endg);
263  	      if (__testout)
264  		{
265  		  _M_pbump(__base, __endp, __o);
266  		  // egptr() always tracks the string end.  When !__testin,
267  		  // for the correct functioning of the streambuf inlines
268  		  // the other get area pointers are identical.
269  		  if (!__testin)
270  		    this->setg(__endg, __endg, __endg);
271  		}
272  	    }
273  	
274  	  template <class _CharT, class _Traits, class _Alloc>
275  	    void
276  	    basic_stringbuf<_CharT, _Traits, _Alloc>::
277  	    _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off)
278  	    {
279  	      this->setp(__pbeg, __pend);
280  	      while (__off > __gnu_cxx::__numeric_traits<int>::__max)
281  		{
282  		  this->pbump(__gnu_cxx::__numeric_traits<int>::__max);
283  		  __off -= __gnu_cxx::__numeric_traits<int>::__max;
284  		}
285  	      this->pbump(__off);
286  	    }
287  	
288  	  // Inhibit implicit instantiations for required instantiations,
289  	  // which are defined via explicit instantiations elsewhere.
290  	#if _GLIBCXX_EXTERN_TEMPLATE
291  	  extern template class basic_stringbuf<char>;
292  	  extern template class basic_istringstream<char>;
293  	  extern template class basic_ostringstream<char>;
294  	  extern template class basic_stringstream<char>;
295  	
296  	#ifdef _GLIBCXX_USE_WCHAR_T
297  	  extern template class basic_stringbuf<wchar_t>;
298  	  extern template class basic_istringstream<wchar_t>;
299  	  extern template class basic_ostringstream<wchar_t>;
300  	  extern template class basic_stringstream<wchar_t>;
301  	#endif
302  	#endif
303  	
304  	_GLIBCXX_END_NAMESPACE_VERSION
305  	} // namespace std
306  	
307  	#endif
308