1*f8a1b7d9SAlexander Kabaev // Reference-counted versatile string base -*- C++ -*-
2*f8a1b7d9SAlexander Kabaev 
3*f8a1b7d9SAlexander Kabaev // Copyright (C) 2005, 2006 Free Software Foundation, Inc.
4*f8a1b7d9SAlexander Kabaev //
5*f8a1b7d9SAlexander Kabaev // This file is part of the GNU ISO C++ Library.  This library is free
6*f8a1b7d9SAlexander Kabaev // software; you can redistribute it and/or modify it under the
7*f8a1b7d9SAlexander Kabaev // terms of the GNU General Public License as published by the
8*f8a1b7d9SAlexander Kabaev // Free Software Foundation; either version 2, or (at your option)
9*f8a1b7d9SAlexander Kabaev // any later version.
10*f8a1b7d9SAlexander Kabaev 
11*f8a1b7d9SAlexander Kabaev // This library is distributed in the hope that it will be useful,
12*f8a1b7d9SAlexander Kabaev // but WITHOUT ANY WARRANTY; without even the implied warranty of
13*f8a1b7d9SAlexander Kabaev // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14*f8a1b7d9SAlexander Kabaev // GNU General Public License for more details.
15*f8a1b7d9SAlexander Kabaev 
16*f8a1b7d9SAlexander Kabaev // You should have received a copy of the GNU General Public License along
17*f8a1b7d9SAlexander Kabaev // with this library; see the file COPYING.  If not, write to the Free
18*f8a1b7d9SAlexander Kabaev // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
19*f8a1b7d9SAlexander Kabaev // USA.
20*f8a1b7d9SAlexander Kabaev 
21*f8a1b7d9SAlexander Kabaev // As a special exception, you may use this file as part of a free software
22*f8a1b7d9SAlexander Kabaev // library without restriction.  Specifically, if other files instantiate
23*f8a1b7d9SAlexander Kabaev // templates or use macros or inline functions from this file, or you compile
24*f8a1b7d9SAlexander Kabaev // this file and link it with other files to produce an executable, this
25*f8a1b7d9SAlexander Kabaev // file does not by itself cause the resulting executable to be covered by
26*f8a1b7d9SAlexander Kabaev // the GNU General Public License.  This exception does not however
27*f8a1b7d9SAlexander Kabaev // invalidate any other reasons why the executable file might be covered by
28*f8a1b7d9SAlexander Kabaev // the GNU General Public License.
29*f8a1b7d9SAlexander Kabaev 
30*f8a1b7d9SAlexander Kabaev /** @file ext/rc_string_base.h
31*f8a1b7d9SAlexander Kabaev  *  This file is a GNU extension to the Standard C++ Library.
32*f8a1b7d9SAlexander Kabaev  *  This is an internal header file, included by other library headers.
33*f8a1b7d9SAlexander Kabaev  *  You should not attempt to use it directly.
34*f8a1b7d9SAlexander Kabaev  */
35*f8a1b7d9SAlexander Kabaev 
36*f8a1b7d9SAlexander Kabaev #ifndef _RC_STRING_BASE_H
37*f8a1b7d9SAlexander Kabaev #define _RC_STRING_BASE_H 1
38*f8a1b7d9SAlexander Kabaev 
39*f8a1b7d9SAlexander Kabaev #include <ext/atomicity.h>
40*f8a1b7d9SAlexander Kabaev 
_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)41*f8a1b7d9SAlexander Kabaev _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
42*f8a1b7d9SAlexander Kabaev 
43*f8a1b7d9SAlexander Kabaev   /**
44*f8a1b7d9SAlexander Kabaev    *  @if maint
45*f8a1b7d9SAlexander Kabaev    *  Documentation?  What's that?
46*f8a1b7d9SAlexander Kabaev    *  Nathan Myers <[email protected]>.
47*f8a1b7d9SAlexander Kabaev    *
48*f8a1b7d9SAlexander Kabaev    *  A string looks like this:
49*f8a1b7d9SAlexander Kabaev    *
50*f8a1b7d9SAlexander Kabaev    *  @code
51*f8a1b7d9SAlexander Kabaev    *                                        [_Rep]
52*f8a1b7d9SAlexander Kabaev    *                                        _M_length
53*f8a1b7d9SAlexander Kabaev    *   [__rc_string_base<char_type>]        _M_capacity
54*f8a1b7d9SAlexander Kabaev    *   _M_dataplus                          _M_refcount
55*f8a1b7d9SAlexander Kabaev    *   _M_p ---------------->               unnamed array of char_type
56*f8a1b7d9SAlexander Kabaev    *  @endcode
57*f8a1b7d9SAlexander Kabaev    *
58*f8a1b7d9SAlexander Kabaev    *  Where the _M_p points to the first character in the string, and
59*f8a1b7d9SAlexander Kabaev    *  you cast it to a pointer-to-_Rep and subtract 1 to get a
60*f8a1b7d9SAlexander Kabaev    *  pointer to the header.
61*f8a1b7d9SAlexander Kabaev    *
62*f8a1b7d9SAlexander Kabaev    *  This approach has the enormous advantage that a string object
63*f8a1b7d9SAlexander Kabaev    *  requires only one allocation.  All the ugliness is confined
64*f8a1b7d9SAlexander Kabaev    *  within a single pair of inline functions, which each compile to
65*f8a1b7d9SAlexander Kabaev    *  a single "add" instruction: _Rep::_M_refdata(), and
66*f8a1b7d9SAlexander Kabaev    *  __rc_string_base::_M_rep(); and the allocation function which gets a
67*f8a1b7d9SAlexander Kabaev    *  block of raw bytes and with room enough and constructs a _Rep
68*f8a1b7d9SAlexander Kabaev    *  object at the front.
69*f8a1b7d9SAlexander Kabaev    *
70*f8a1b7d9SAlexander Kabaev    *  The reason you want _M_data pointing to the character array and
71*f8a1b7d9SAlexander Kabaev    *  not the _Rep is so that the debugger can see the string
72*f8a1b7d9SAlexander Kabaev    *  contents. (Probably we should add a non-inline member to get
73*f8a1b7d9SAlexander Kabaev    *  the _Rep for the debugger to use, so users can check the actual
74*f8a1b7d9SAlexander Kabaev    *  string length.)
75*f8a1b7d9SAlexander Kabaev    *
76*f8a1b7d9SAlexander Kabaev    *  Note that the _Rep object is a POD so that you can have a
77*f8a1b7d9SAlexander Kabaev    *  static "empty string" _Rep object already "constructed" before
78*f8a1b7d9SAlexander Kabaev    *  static constructors have run.  The reference-count encoding is
79*f8a1b7d9SAlexander Kabaev    *  chosen so that a 0 indicates one reference, so you never try to
80*f8a1b7d9SAlexander Kabaev    *  destroy the empty-string _Rep object.
81*f8a1b7d9SAlexander Kabaev    *
82*f8a1b7d9SAlexander Kabaev    *  All but the last paragraph is considered pretty conventional
83*f8a1b7d9SAlexander Kabaev    *  for a C++ string implementation.
84*f8a1b7d9SAlexander Kabaev    *  @endif
85*f8a1b7d9SAlexander Kabaev   */
86*f8a1b7d9SAlexander Kabaev  template<typename _CharT, typename _Traits, typename _Alloc>
87*f8a1b7d9SAlexander Kabaev     class __rc_string_base
88*f8a1b7d9SAlexander Kabaev     : protected __vstring_utility<_CharT, _Traits, _Alloc>
89*f8a1b7d9SAlexander Kabaev     {
90*f8a1b7d9SAlexander Kabaev     public:
91*f8a1b7d9SAlexander Kabaev       typedef _Traits					    traits_type;
92*f8a1b7d9SAlexander Kabaev       typedef typename _Traits::char_type		    value_type;
93*f8a1b7d9SAlexander Kabaev       typedef _Alloc					    allocator_type;
94*f8a1b7d9SAlexander Kabaev 
95*f8a1b7d9SAlexander Kabaev       typedef __vstring_utility<_CharT, _Traits, _Alloc>    _Util_Base;
96*f8a1b7d9SAlexander Kabaev       typedef typename _Util_Base::_CharT_alloc_type        _CharT_alloc_type;
97*f8a1b7d9SAlexander Kabaev       typedef typename _CharT_alloc_type::size_type	    size_type;
98*f8a1b7d9SAlexander Kabaev 
99*f8a1b7d9SAlexander Kabaev     private:
100*f8a1b7d9SAlexander Kabaev       // _Rep: string representation
101*f8a1b7d9SAlexander Kabaev       //   Invariants:
102*f8a1b7d9SAlexander Kabaev       //   1. String really contains _M_length + 1 characters: due to 21.3.4
103*f8a1b7d9SAlexander Kabaev       //      must be kept null-terminated.
104*f8a1b7d9SAlexander Kabaev       //   2. _M_capacity >= _M_length
105*f8a1b7d9SAlexander Kabaev       //      Allocated memory is always (_M_capacity + 1) * sizeof(_CharT).
106*f8a1b7d9SAlexander Kabaev       //   3. _M_refcount has three states:
107*f8a1b7d9SAlexander Kabaev       //      -1: leaked, one reference, no ref-copies allowed, non-const.
108*f8a1b7d9SAlexander Kabaev       //       0: one reference, non-const.
109*f8a1b7d9SAlexander Kabaev       //     n>0: n + 1 references, operations require a lock, const.
110*f8a1b7d9SAlexander Kabaev       //   4. All fields == 0 is an empty string, given the extra storage
111*f8a1b7d9SAlexander Kabaev       //      beyond-the-end for a null terminator; thus, the shared
112*f8a1b7d9SAlexander Kabaev       //      empty string representation needs no constructor.
113*f8a1b7d9SAlexander Kabaev       struct _Rep
114*f8a1b7d9SAlexander Kabaev       {
115*f8a1b7d9SAlexander Kabaev 	union
116*f8a1b7d9SAlexander Kabaev 	{
117*f8a1b7d9SAlexander Kabaev 	  struct
118*f8a1b7d9SAlexander Kabaev 	  {
119*f8a1b7d9SAlexander Kabaev 	    size_type	    _M_length;
120*f8a1b7d9SAlexander Kabaev 	    size_type	    _M_capacity;
121*f8a1b7d9SAlexander Kabaev 	    _Atomic_word    _M_refcount;
122*f8a1b7d9SAlexander Kabaev 	  }                 _M_info;
123*f8a1b7d9SAlexander Kabaev 
124*f8a1b7d9SAlexander Kabaev 	  // Only for alignment purposes.
125*f8a1b7d9SAlexander Kabaev 	  _CharT            _M_align;
126*f8a1b7d9SAlexander Kabaev 	};
127*f8a1b7d9SAlexander Kabaev 
128*f8a1b7d9SAlexander Kabaev 	typedef typename _Alloc::template rebind<_Rep>::other _Rep_alloc_type;
129*f8a1b7d9SAlexander Kabaev 
130*f8a1b7d9SAlexander Kabaev  	_CharT*
131*f8a1b7d9SAlexander Kabaev 	_M_refdata() throw()
132*f8a1b7d9SAlexander Kabaev 	{ return reinterpret_cast<_CharT*>(this + 1); }
133*f8a1b7d9SAlexander Kabaev 
134*f8a1b7d9SAlexander Kabaev 	_CharT*
135*f8a1b7d9SAlexander Kabaev 	_M_refcopy() throw()
136*f8a1b7d9SAlexander Kabaev 	{
137*f8a1b7d9SAlexander Kabaev 	  __atomic_add_dispatch(&_M_info._M_refcount, 1);
138*f8a1b7d9SAlexander Kabaev 	  return _M_refdata();
139*f8a1b7d9SAlexander Kabaev 	}  // XXX MT
140*f8a1b7d9SAlexander Kabaev 
141*f8a1b7d9SAlexander Kabaev 	void
142*f8a1b7d9SAlexander Kabaev 	_M_set_length(size_type __n)
143*f8a1b7d9SAlexander Kabaev 	{
144*f8a1b7d9SAlexander Kabaev 	  _M_info._M_refcount = 0;  // One reference.
145*f8a1b7d9SAlexander Kabaev 	  _M_info._M_length = __n;
146*f8a1b7d9SAlexander Kabaev 	  // grrr. (per 21.3.4)
147*f8a1b7d9SAlexander Kabaev 	  // You cannot leave those LWG people alone for a second.
148*f8a1b7d9SAlexander Kabaev 	  traits_type::assign(_M_refdata()[__n], _CharT());
149*f8a1b7d9SAlexander Kabaev 	}
150*f8a1b7d9SAlexander Kabaev 
151*f8a1b7d9SAlexander Kabaev 	// Create & Destroy
152*f8a1b7d9SAlexander Kabaev 	static _Rep*
153*f8a1b7d9SAlexander Kabaev 	_S_create(size_type, size_type, const _Alloc&);
154*f8a1b7d9SAlexander Kabaev 
155*f8a1b7d9SAlexander Kabaev 	void
156*f8a1b7d9SAlexander Kabaev 	_M_destroy(const _Alloc&) throw();
157*f8a1b7d9SAlexander Kabaev 
158*f8a1b7d9SAlexander Kabaev 	_CharT*
159*f8a1b7d9SAlexander Kabaev 	_M_clone(const _Alloc&, size_type __res = 0);
160*f8a1b7d9SAlexander Kabaev       };
161*f8a1b7d9SAlexander Kabaev 
162*f8a1b7d9SAlexander Kabaev       struct _Rep_empty
163*f8a1b7d9SAlexander Kabaev       : public _Rep
164*f8a1b7d9SAlexander Kabaev       {
165*f8a1b7d9SAlexander Kabaev 	_CharT              _M_terminal;
166*f8a1b7d9SAlexander Kabaev       };
167*f8a1b7d9SAlexander Kabaev 
168*f8a1b7d9SAlexander Kabaev       static _Rep_empty     _S_empty_rep;
169*f8a1b7d9SAlexander Kabaev 
170*f8a1b7d9SAlexander Kabaev       // The maximum number of individual char_type elements of an
171*f8a1b7d9SAlexander Kabaev       // individual string is determined by _S_max_size. This is the
172*f8a1b7d9SAlexander Kabaev       // value that will be returned by max_size().  (Whereas npos
173*f8a1b7d9SAlexander Kabaev       // is the maximum number of bytes the allocator can allocate.)
174*f8a1b7d9SAlexander Kabaev       // If one was to divvy up the theoretical largest size string,
175*f8a1b7d9SAlexander Kabaev       // with a terminating character and m _CharT elements, it'd
176*f8a1b7d9SAlexander Kabaev       // look like this:
177*f8a1b7d9SAlexander Kabaev       // npos = sizeof(_Rep) + (m * sizeof(_CharT)) + sizeof(_CharT)
178*f8a1b7d9SAlexander Kabaev       //        + sizeof(_Rep) - 1
179*f8a1b7d9SAlexander Kabaev       // (NB: last two terms for rounding reasons, see _M_create below)
180*f8a1b7d9SAlexander Kabaev       // Solving for m:
181*f8a1b7d9SAlexander Kabaev       // m = ((npos - 2 * sizeof(_Rep) + 1) / sizeof(_CharT)) - 1
182*f8a1b7d9SAlexander Kabaev       // In addition, this implementation halfs this amount.
183*f8a1b7d9SAlexander Kabaev       enum { _S_max_size = (((static_cast<size_type>(-1) - 2 * sizeof(_Rep)
184*f8a1b7d9SAlexander Kabaev 			      + 1) / sizeof(_CharT)) - 1) / 2 };
185*f8a1b7d9SAlexander Kabaev 
186*f8a1b7d9SAlexander Kabaev       // Data Member (private):
187*f8a1b7d9SAlexander Kabaev       mutable typename _Util_Base::template _Alloc_hider<_Alloc>  _M_dataplus;
188*f8a1b7d9SAlexander Kabaev 
189*f8a1b7d9SAlexander Kabaev       void
190*f8a1b7d9SAlexander Kabaev       _M_data(_CharT* __p)
191*f8a1b7d9SAlexander Kabaev       { _M_dataplus._M_p = __p; }
192*f8a1b7d9SAlexander Kabaev 
193*f8a1b7d9SAlexander Kabaev       _Rep*
194*f8a1b7d9SAlexander Kabaev       _M_rep() const
195*f8a1b7d9SAlexander Kabaev       { return &((reinterpret_cast<_Rep*>(_M_data()))[-1]); }
196*f8a1b7d9SAlexander Kabaev 
197*f8a1b7d9SAlexander Kabaev       _CharT*
198*f8a1b7d9SAlexander Kabaev       _M_grab(const _Alloc& __alloc) const
199*f8a1b7d9SAlexander Kabaev       {
200*f8a1b7d9SAlexander Kabaev 	return (!_M_is_leaked() && _M_get_allocator() == __alloc)
201*f8a1b7d9SAlexander Kabaev 	        ? _M_rep()->_M_refcopy() : _M_rep()->_M_clone(__alloc);
202*f8a1b7d9SAlexander Kabaev       }
203*f8a1b7d9SAlexander Kabaev 
204*f8a1b7d9SAlexander Kabaev       void
205*f8a1b7d9SAlexander Kabaev       _M_dispose()
206*f8a1b7d9SAlexander Kabaev       {
207*f8a1b7d9SAlexander Kabaev 	if (__exchange_and_add_dispatch(&_M_rep()->_M_info._M_refcount,
208*f8a1b7d9SAlexander Kabaev 					-1) <= 0)
209*f8a1b7d9SAlexander Kabaev 	  _M_rep()->_M_destroy(_M_get_allocator());
210*f8a1b7d9SAlexander Kabaev       }  // XXX MT
211*f8a1b7d9SAlexander Kabaev 
212*f8a1b7d9SAlexander Kabaev       bool
213*f8a1b7d9SAlexander Kabaev       _M_is_leaked() const
214*f8a1b7d9SAlexander Kabaev       { return _M_rep()->_M_info._M_refcount < 0; }
215*f8a1b7d9SAlexander Kabaev 
216*f8a1b7d9SAlexander Kabaev       void
217*f8a1b7d9SAlexander Kabaev       _M_set_sharable()
218*f8a1b7d9SAlexander Kabaev       { _M_rep()->_M_info._M_refcount = 0; }
219*f8a1b7d9SAlexander Kabaev 
220*f8a1b7d9SAlexander Kabaev       void
221*f8a1b7d9SAlexander Kabaev       _M_leak_hard();
222*f8a1b7d9SAlexander Kabaev 
223*f8a1b7d9SAlexander Kabaev       // _S_construct_aux is used to implement the 21.3.1 para 15 which
224*f8a1b7d9SAlexander Kabaev       // requires special behaviour if _InIterator is an integral type
225*f8a1b7d9SAlexander Kabaev       template<typename _InIterator>
226*f8a1b7d9SAlexander Kabaev         static _CharT*
227*f8a1b7d9SAlexander Kabaev         _S_construct_aux(_InIterator __beg, _InIterator __end,
228*f8a1b7d9SAlexander Kabaev 			 const _Alloc& __a, std::__false_type)
229*f8a1b7d9SAlexander Kabaev 	{
230*f8a1b7d9SAlexander Kabaev           typedef typename iterator_traits<_InIterator>::iterator_category _Tag;
231*f8a1b7d9SAlexander Kabaev           return _S_construct(__beg, __end, __a, _Tag());
232*f8a1b7d9SAlexander Kabaev 	}
233*f8a1b7d9SAlexander Kabaev 
234*f8a1b7d9SAlexander Kabaev       template<typename _InIterator>
235*f8a1b7d9SAlexander Kabaev         static _CharT*
236*f8a1b7d9SAlexander Kabaev         _S_construct_aux(_InIterator __beg, _InIterator __end,
237*f8a1b7d9SAlexander Kabaev 			 const _Alloc& __a, std::__true_type)
238*f8a1b7d9SAlexander Kabaev 	{ return _S_construct(static_cast<size_type>(__beg),
239*f8a1b7d9SAlexander Kabaev 			      static_cast<value_type>(__end), __a); }
240*f8a1b7d9SAlexander Kabaev 
241*f8a1b7d9SAlexander Kabaev       template<typename _InIterator>
242*f8a1b7d9SAlexander Kabaev         static _CharT*
243*f8a1b7d9SAlexander Kabaev         _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a)
244*f8a1b7d9SAlexander Kabaev 	{
245*f8a1b7d9SAlexander Kabaev 	  typedef typename std::__is_integer<_InIterator>::__type _Integral;
246*f8a1b7d9SAlexander Kabaev 	  return _S_construct_aux(__beg, __end, __a, _Integral());
247*f8a1b7d9SAlexander Kabaev         }
248*f8a1b7d9SAlexander Kabaev 
249*f8a1b7d9SAlexander Kabaev       // For Input Iterators, used in istreambuf_iterators, etc.
250*f8a1b7d9SAlexander Kabaev       template<typename _InIterator>
251*f8a1b7d9SAlexander Kabaev         static _CharT*
252*f8a1b7d9SAlexander Kabaev          _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
253*f8a1b7d9SAlexander Kabaev 		      std::input_iterator_tag);
254*f8a1b7d9SAlexander Kabaev 
255*f8a1b7d9SAlexander Kabaev       // For forward_iterators up to random_access_iterators, used for
256*f8a1b7d9SAlexander Kabaev       // string::iterator, _CharT*, etc.
257*f8a1b7d9SAlexander Kabaev       template<typename _FwdIterator>
258*f8a1b7d9SAlexander Kabaev         static _CharT*
259*f8a1b7d9SAlexander Kabaev         _S_construct(_FwdIterator __beg, _FwdIterator __end, const _Alloc& __a,
260*f8a1b7d9SAlexander Kabaev 		     std::forward_iterator_tag);
261*f8a1b7d9SAlexander Kabaev 
262*f8a1b7d9SAlexander Kabaev       static _CharT*
263*f8a1b7d9SAlexander Kabaev       _S_construct(size_type __req, _CharT __c, const _Alloc& __a);
264*f8a1b7d9SAlexander Kabaev 
265*f8a1b7d9SAlexander Kabaev     public:
266*f8a1b7d9SAlexander Kabaev       size_type
267*f8a1b7d9SAlexander Kabaev       _M_max_size() const
268*f8a1b7d9SAlexander Kabaev       { return size_type(_S_max_size); }
269*f8a1b7d9SAlexander Kabaev 
270*f8a1b7d9SAlexander Kabaev       _CharT*
271*f8a1b7d9SAlexander Kabaev       _M_data() const
272*f8a1b7d9SAlexander Kabaev       { return _M_dataplus._M_p; }
273*f8a1b7d9SAlexander Kabaev 
274*f8a1b7d9SAlexander Kabaev       size_type
275*f8a1b7d9SAlexander Kabaev       _M_length() const
276*f8a1b7d9SAlexander Kabaev       { return _M_rep()->_M_info._M_length; }
277*f8a1b7d9SAlexander Kabaev 
278*f8a1b7d9SAlexander Kabaev       size_type
279*f8a1b7d9SAlexander Kabaev       _M_capacity() const
280*f8a1b7d9SAlexander Kabaev       { return _M_rep()->_M_info._M_capacity; }
281*f8a1b7d9SAlexander Kabaev 
282*f8a1b7d9SAlexander Kabaev       bool
283*f8a1b7d9SAlexander Kabaev       _M_is_shared() const
284*f8a1b7d9SAlexander Kabaev       { return _M_rep()->_M_info._M_refcount > 0; }
285*f8a1b7d9SAlexander Kabaev 
286*f8a1b7d9SAlexander Kabaev       void
287*f8a1b7d9SAlexander Kabaev       _M_set_leaked()
288*f8a1b7d9SAlexander Kabaev       { _M_rep()->_M_info._M_refcount = -1; }
289*f8a1b7d9SAlexander Kabaev 
290*f8a1b7d9SAlexander Kabaev       void
291*f8a1b7d9SAlexander Kabaev       _M_leak()    // for use in begin() & non-const op[]
292*f8a1b7d9SAlexander Kabaev       {
293*f8a1b7d9SAlexander Kabaev 	if (!_M_is_leaked())
294*f8a1b7d9SAlexander Kabaev 	  _M_leak_hard();
295*f8a1b7d9SAlexander Kabaev       }
296*f8a1b7d9SAlexander Kabaev 
297*f8a1b7d9SAlexander Kabaev       void
298*f8a1b7d9SAlexander Kabaev       _M_set_length(size_type __n)
299*f8a1b7d9SAlexander Kabaev       { _M_rep()->_M_set_length(__n); }
300*f8a1b7d9SAlexander Kabaev 
301*f8a1b7d9SAlexander Kabaev       __rc_string_base()
302*f8a1b7d9SAlexander Kabaev       : _M_dataplus(_Alloc(), _S_empty_rep._M_refcopy()) { }
303*f8a1b7d9SAlexander Kabaev 
304*f8a1b7d9SAlexander Kabaev       __rc_string_base(const _Alloc& __a);
305*f8a1b7d9SAlexander Kabaev 
306*f8a1b7d9SAlexander Kabaev       __rc_string_base(const __rc_string_base& __rcs);
307*f8a1b7d9SAlexander Kabaev 
308*f8a1b7d9SAlexander Kabaev       __rc_string_base(size_type __n, _CharT __c, const _Alloc& __a);
309*f8a1b7d9SAlexander Kabaev 
310*f8a1b7d9SAlexander Kabaev       template<typename _InputIterator>
311*f8a1b7d9SAlexander Kabaev         __rc_string_base(_InputIterator __beg, _InputIterator __end,
312*f8a1b7d9SAlexander Kabaev 			 const _Alloc& __a);
313*f8a1b7d9SAlexander Kabaev 
314*f8a1b7d9SAlexander Kabaev       ~__rc_string_base()
315*f8a1b7d9SAlexander Kabaev       { _M_dispose(); }
316*f8a1b7d9SAlexander Kabaev 
317*f8a1b7d9SAlexander Kabaev       allocator_type&
318*f8a1b7d9SAlexander Kabaev       _M_get_allocator()
319*f8a1b7d9SAlexander Kabaev       { return _M_dataplus; }
320*f8a1b7d9SAlexander Kabaev 
321*f8a1b7d9SAlexander Kabaev       const allocator_type&
322*f8a1b7d9SAlexander Kabaev       _M_get_allocator() const
323*f8a1b7d9SAlexander Kabaev       { return _M_dataplus; }
324*f8a1b7d9SAlexander Kabaev 
325*f8a1b7d9SAlexander Kabaev       void
326*f8a1b7d9SAlexander Kabaev       _M_swap(__rc_string_base& __rcs);
327*f8a1b7d9SAlexander Kabaev 
328*f8a1b7d9SAlexander Kabaev       void
329*f8a1b7d9SAlexander Kabaev       _M_assign(const __rc_string_base& __rcs);
330*f8a1b7d9SAlexander Kabaev 
331*f8a1b7d9SAlexander Kabaev       void
332*f8a1b7d9SAlexander Kabaev       _M_reserve(size_type __res);
333*f8a1b7d9SAlexander Kabaev 
334*f8a1b7d9SAlexander Kabaev       void
335*f8a1b7d9SAlexander Kabaev       _M_mutate(size_type __pos, size_type __len1, const _CharT* __s,
336*f8a1b7d9SAlexander Kabaev 		size_type __len2);
337*f8a1b7d9SAlexander Kabaev 
338*f8a1b7d9SAlexander Kabaev       void
339*f8a1b7d9SAlexander Kabaev       _M_erase(size_type __pos, size_type __n);
340*f8a1b7d9SAlexander Kabaev 
341*f8a1b7d9SAlexander Kabaev       void
342*f8a1b7d9SAlexander Kabaev       _M_clear()
343*f8a1b7d9SAlexander Kabaev       { _M_erase(size_type(0), _M_length()); }
344*f8a1b7d9SAlexander Kabaev 
345*f8a1b7d9SAlexander Kabaev       bool
346*f8a1b7d9SAlexander Kabaev       _M_compare(const __rc_string_base&) const
347*f8a1b7d9SAlexander Kabaev       { return false; }
348*f8a1b7d9SAlexander Kabaev     };
349*f8a1b7d9SAlexander Kabaev 
350*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
351*f8a1b7d9SAlexander Kabaev     typename __rc_string_base<_CharT, _Traits, _Alloc>::_Rep_empty
352*f8a1b7d9SAlexander Kabaev     __rc_string_base<_CharT, _Traits, _Alloc>::_S_empty_rep;
353*f8a1b7d9SAlexander Kabaev 
354*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
355*f8a1b7d9SAlexander Kabaev     typename __rc_string_base<_CharT, _Traits, _Alloc>::_Rep*
356*f8a1b7d9SAlexander Kabaev     __rc_string_base<_CharT, _Traits, _Alloc>::_Rep::
_S_create(size_type __capacity,size_type __old_capacity,const _Alloc & __alloc)357*f8a1b7d9SAlexander Kabaev     _S_create(size_type __capacity, size_type __old_capacity,
358*f8a1b7d9SAlexander Kabaev 	      const _Alloc& __alloc)
359*f8a1b7d9SAlexander Kabaev     {
360*f8a1b7d9SAlexander Kabaev       // _GLIBCXX_RESOLVE_LIB_DEFECTS
361*f8a1b7d9SAlexander Kabaev       // 83.  String::npos vs. string::max_size()
362*f8a1b7d9SAlexander Kabaev       if (__capacity > size_type(_S_max_size))
363*f8a1b7d9SAlexander Kabaev 	std::__throw_length_error(__N("__rc_string_base::_Rep::_S_create"));
364*f8a1b7d9SAlexander Kabaev 
365*f8a1b7d9SAlexander Kabaev       // The standard places no restriction on allocating more memory
366*f8a1b7d9SAlexander Kabaev       // than is strictly needed within this layer at the moment or as
367*f8a1b7d9SAlexander Kabaev       // requested by an explicit application call to reserve().
368*f8a1b7d9SAlexander Kabaev 
369*f8a1b7d9SAlexander Kabaev       // Many malloc implementations perform quite poorly when an
370*f8a1b7d9SAlexander Kabaev       // application attempts to allocate memory in a stepwise fashion
371*f8a1b7d9SAlexander Kabaev       // growing each allocation size by only 1 char.  Additionally,
372*f8a1b7d9SAlexander Kabaev       // it makes little sense to allocate less linear memory than the
373*f8a1b7d9SAlexander Kabaev       // natural blocking size of the malloc implementation.
374*f8a1b7d9SAlexander Kabaev       // Unfortunately, we would need a somewhat low-level calculation
375*f8a1b7d9SAlexander Kabaev       // with tuned parameters to get this perfect for any particular
376*f8a1b7d9SAlexander Kabaev       // malloc implementation.  Fortunately, generalizations about
377*f8a1b7d9SAlexander Kabaev       // common features seen among implementations seems to suffice.
378*f8a1b7d9SAlexander Kabaev 
379*f8a1b7d9SAlexander Kabaev       // __pagesize need not match the actual VM page size for good
380*f8a1b7d9SAlexander Kabaev       // results in practice, thus we pick a common value on the low
381*f8a1b7d9SAlexander Kabaev       // side.  __malloc_header_size is an estimate of the amount of
382*f8a1b7d9SAlexander Kabaev       // overhead per memory allocation (in practice seen N * sizeof
383*f8a1b7d9SAlexander Kabaev       // (void*) where N is 0, 2 or 4).  According to folklore,
384*f8a1b7d9SAlexander Kabaev       // picking this value on the high side is better than
385*f8a1b7d9SAlexander Kabaev       // low-balling it (especially when this algorithm is used with
386*f8a1b7d9SAlexander Kabaev       // malloc implementations that allocate memory blocks rounded up
387*f8a1b7d9SAlexander Kabaev       // to a size which is a power of 2).
388*f8a1b7d9SAlexander Kabaev       const size_type __pagesize = 4096;
389*f8a1b7d9SAlexander Kabaev       const size_type __malloc_header_size = 4 * sizeof(void*);
390*f8a1b7d9SAlexander Kabaev 
391*f8a1b7d9SAlexander Kabaev       // The below implements an exponential growth policy, necessary to
392*f8a1b7d9SAlexander Kabaev       // meet amortized linear time requirements of the library: see
393*f8a1b7d9SAlexander Kabaev       // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html.
394*f8a1b7d9SAlexander Kabaev       if (__capacity > __old_capacity && __capacity < 2 * __old_capacity)
395*f8a1b7d9SAlexander Kabaev 	{
396*f8a1b7d9SAlexander Kabaev 	  __capacity = 2 * __old_capacity;
397*f8a1b7d9SAlexander Kabaev 	  // Never allocate a string bigger than _S_max_size.
398*f8a1b7d9SAlexander Kabaev 	  if (__capacity > size_type(_S_max_size))
399*f8a1b7d9SAlexander Kabaev 	    __capacity = size_type(_S_max_size);
400*f8a1b7d9SAlexander Kabaev 	}
401*f8a1b7d9SAlexander Kabaev 
402*f8a1b7d9SAlexander Kabaev       // NB: Need an array of char_type[__capacity], plus a terminating
403*f8a1b7d9SAlexander Kabaev       // null char_type() element, plus enough for the _Rep data structure,
404*f8a1b7d9SAlexander Kabaev       // plus sizeof(_Rep) - 1 to upper round to a size multiple of
405*f8a1b7d9SAlexander Kabaev       // sizeof(_Rep).
406*f8a1b7d9SAlexander Kabaev       // Whew. Seemingly so needy, yet so elemental.
407*f8a1b7d9SAlexander Kabaev       size_type __size = ((__capacity + 1) * sizeof(_CharT)
408*f8a1b7d9SAlexander Kabaev 			  + 2 * sizeof(_Rep) - 1);
409*f8a1b7d9SAlexander Kabaev 
410*f8a1b7d9SAlexander Kabaev       const size_type __adj_size = __size + __malloc_header_size;
411*f8a1b7d9SAlexander Kabaev       if (__adj_size > __pagesize && __capacity > __old_capacity)
412*f8a1b7d9SAlexander Kabaev 	{
413*f8a1b7d9SAlexander Kabaev 	  const size_type __extra = __pagesize - __adj_size % __pagesize;
414*f8a1b7d9SAlexander Kabaev 	  __capacity += __extra / sizeof(_CharT);
415*f8a1b7d9SAlexander Kabaev 	  if (__capacity > size_type(_S_max_size))
416*f8a1b7d9SAlexander Kabaev 	    __capacity = size_type(_S_max_size);
417*f8a1b7d9SAlexander Kabaev 	  __size = (__capacity + 1) * sizeof(_CharT) + 2 * sizeof(_Rep) - 1;
418*f8a1b7d9SAlexander Kabaev 	}
419*f8a1b7d9SAlexander Kabaev 
420*f8a1b7d9SAlexander Kabaev       // NB: Might throw, but no worries about a leak, mate: _Rep()
421*f8a1b7d9SAlexander Kabaev       // does not throw.
422*f8a1b7d9SAlexander Kabaev       _Rep* __place = _Rep_alloc_type(__alloc).allocate(__size / sizeof(_Rep));
423*f8a1b7d9SAlexander Kabaev       _Rep* __p = new (__place) _Rep;
424*f8a1b7d9SAlexander Kabaev       __p->_M_info._M_capacity = __capacity;
425*f8a1b7d9SAlexander Kabaev       return __p;
426*f8a1b7d9SAlexander Kabaev     }
427*f8a1b7d9SAlexander Kabaev 
428*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
429*f8a1b7d9SAlexander Kabaev     void
430*f8a1b7d9SAlexander Kabaev     __rc_string_base<_CharT, _Traits, _Alloc>::_Rep::
_M_destroy(const _Alloc & __a)431*f8a1b7d9SAlexander Kabaev     _M_destroy(const _Alloc& __a) throw ()
432*f8a1b7d9SAlexander Kabaev     {
433*f8a1b7d9SAlexander Kabaev       const size_type __size = ((_M_info._M_capacity + 1) * sizeof(_CharT)
434*f8a1b7d9SAlexander Kabaev 				+ 2 * sizeof(_Rep) - 1);
435*f8a1b7d9SAlexander Kabaev       _Rep_alloc_type(__a).deallocate(this, __size / sizeof(_Rep));
436*f8a1b7d9SAlexander Kabaev     }
437*f8a1b7d9SAlexander Kabaev 
438*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
439*f8a1b7d9SAlexander Kabaev     _CharT*
440*f8a1b7d9SAlexander Kabaev     __rc_string_base<_CharT, _Traits, _Alloc>::_Rep::
_M_clone(const _Alloc & __alloc,size_type __res)441*f8a1b7d9SAlexander Kabaev     _M_clone(const _Alloc& __alloc, size_type __res)
442*f8a1b7d9SAlexander Kabaev     {
443*f8a1b7d9SAlexander Kabaev       // Requested capacity of the clone.
444*f8a1b7d9SAlexander Kabaev       const size_type __requested_cap = _M_info._M_length + __res;
445*f8a1b7d9SAlexander Kabaev       _Rep* __r = _Rep::_S_create(__requested_cap, _M_info._M_capacity,
446*f8a1b7d9SAlexander Kabaev 				  __alloc);
447*f8a1b7d9SAlexander Kabaev 
448*f8a1b7d9SAlexander Kabaev       if (_M_info._M_length)
449*f8a1b7d9SAlexander Kabaev 	_S_copy(__r->_M_refdata(), _M_refdata(), _M_info._M_length);
450*f8a1b7d9SAlexander Kabaev 
451*f8a1b7d9SAlexander Kabaev       __r->_M_set_length(_M_info._M_length);
452*f8a1b7d9SAlexander Kabaev       return __r->_M_refdata();
453*f8a1b7d9SAlexander Kabaev     }
454*f8a1b7d9SAlexander Kabaev 
455*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
456*f8a1b7d9SAlexander Kabaev     __rc_string_base<_CharT, _Traits, _Alloc>::
__rc_string_base(const _Alloc & __a)457*f8a1b7d9SAlexander Kabaev     __rc_string_base(const _Alloc& __a)
458*f8a1b7d9SAlexander Kabaev     : _M_dataplus(__a, _S_construct(size_type(), _CharT(), __a)) { }
459*f8a1b7d9SAlexander Kabaev 
460*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
461*f8a1b7d9SAlexander Kabaev     __rc_string_base<_CharT, _Traits, _Alloc>::
__rc_string_base(const __rc_string_base & __rcs)462*f8a1b7d9SAlexander Kabaev     __rc_string_base(const __rc_string_base& __rcs)
463*f8a1b7d9SAlexander Kabaev     : _M_dataplus(__rcs._M_get_allocator(),
464*f8a1b7d9SAlexander Kabaev 		  __rcs._M_grab(__rcs._M_get_allocator())) { }
465*f8a1b7d9SAlexander Kabaev 
466*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
467*f8a1b7d9SAlexander Kabaev     __rc_string_base<_CharT, _Traits, _Alloc>::
__rc_string_base(size_type __n,_CharT __c,const _Alloc & __a)468*f8a1b7d9SAlexander Kabaev     __rc_string_base(size_type __n, _CharT __c, const _Alloc& __a)
469*f8a1b7d9SAlexander Kabaev     : _M_dataplus(__a, _S_construct(__n, __c, __a)) { }
470*f8a1b7d9SAlexander Kabaev 
471*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
472*f8a1b7d9SAlexander Kabaev     template<typename _InputIterator>
473*f8a1b7d9SAlexander Kabaev     __rc_string_base<_CharT, _Traits, _Alloc>::
__rc_string_base(_InputIterator __beg,_InputIterator __end,const _Alloc & __a)474*f8a1b7d9SAlexander Kabaev     __rc_string_base(_InputIterator __beg, _InputIterator __end,
475*f8a1b7d9SAlexander Kabaev 		     const _Alloc& __a)
476*f8a1b7d9SAlexander Kabaev     : _M_dataplus(__a, _S_construct(__beg, __end, __a)) { }
477*f8a1b7d9SAlexander Kabaev 
478*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
479*f8a1b7d9SAlexander Kabaev     void
480*f8a1b7d9SAlexander Kabaev     __rc_string_base<_CharT, _Traits, _Alloc>::
_M_leak_hard()481*f8a1b7d9SAlexander Kabaev     _M_leak_hard()
482*f8a1b7d9SAlexander Kabaev     {
483*f8a1b7d9SAlexander Kabaev       if (_M_is_shared())
484*f8a1b7d9SAlexander Kabaev 	_M_erase(0, 0);
485*f8a1b7d9SAlexander Kabaev       _M_set_leaked();
486*f8a1b7d9SAlexander Kabaev     }
487*f8a1b7d9SAlexander Kabaev 
488*f8a1b7d9SAlexander Kabaev   // NB: This is the special case for Input Iterators, used in
489*f8a1b7d9SAlexander Kabaev   // istreambuf_iterators, etc.
490*f8a1b7d9SAlexander Kabaev   // Input Iterators have a cost structure very different from
491*f8a1b7d9SAlexander Kabaev   // pointers, calling for a different coding style.
492*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
493*f8a1b7d9SAlexander Kabaev     template<typename _InIterator>
494*f8a1b7d9SAlexander Kabaev       _CharT*
495*f8a1b7d9SAlexander Kabaev       __rc_string_base<_CharT, _Traits, _Alloc>::
_S_construct(_InIterator __beg,_InIterator __end,const _Alloc & __a,std::input_iterator_tag)496*f8a1b7d9SAlexander Kabaev       _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
497*f8a1b7d9SAlexander Kabaev 		   std::input_iterator_tag)
498*f8a1b7d9SAlexander Kabaev       {
499*f8a1b7d9SAlexander Kabaev 	if (__beg == __end && __a == _Alloc())
500*f8a1b7d9SAlexander Kabaev 	  return _S_empty_rep._M_refcopy();
501*f8a1b7d9SAlexander Kabaev 
502*f8a1b7d9SAlexander Kabaev 	// Avoid reallocation for common case.
503*f8a1b7d9SAlexander Kabaev 	_CharT __buf[128];
504*f8a1b7d9SAlexander Kabaev 	size_type __len = 0;
505*f8a1b7d9SAlexander Kabaev 	while (__beg != __end && __len < sizeof(__buf) / sizeof(_CharT))
506*f8a1b7d9SAlexander Kabaev 	  {
507*f8a1b7d9SAlexander Kabaev 	    __buf[__len++] = *__beg;
508*f8a1b7d9SAlexander Kabaev 	    ++__beg;
509*f8a1b7d9SAlexander Kabaev 	  }
510*f8a1b7d9SAlexander Kabaev 	_Rep* __r = _Rep::_S_create(__len, size_type(0), __a);
511*f8a1b7d9SAlexander Kabaev 	_S_copy(__r->_M_refdata(), __buf, __len);
512*f8a1b7d9SAlexander Kabaev 	try
513*f8a1b7d9SAlexander Kabaev 	  {
514*f8a1b7d9SAlexander Kabaev 	    while (__beg != __end)
515*f8a1b7d9SAlexander Kabaev 	      {
516*f8a1b7d9SAlexander Kabaev 		if (__len == __r->_M_info._M_capacity)
517*f8a1b7d9SAlexander Kabaev 		  {
518*f8a1b7d9SAlexander Kabaev 		    // Allocate more space.
519*f8a1b7d9SAlexander Kabaev 		    _Rep* __another = _Rep::_S_create(__len + 1, __len, __a);
520*f8a1b7d9SAlexander Kabaev 		    _S_copy(__another->_M_refdata(), __r->_M_refdata(), __len);
521*f8a1b7d9SAlexander Kabaev 		    __r->_M_destroy(__a);
522*f8a1b7d9SAlexander Kabaev 		    __r = __another;
523*f8a1b7d9SAlexander Kabaev 		  }
524*f8a1b7d9SAlexander Kabaev 		__r->_M_refdata()[__len++] = *__beg;
525*f8a1b7d9SAlexander Kabaev 		++__beg;
526*f8a1b7d9SAlexander Kabaev 	      }
527*f8a1b7d9SAlexander Kabaev 	  }
528*f8a1b7d9SAlexander Kabaev 	catch(...)
529*f8a1b7d9SAlexander Kabaev 	  {
530*f8a1b7d9SAlexander Kabaev 	    __r->_M_destroy(__a);
531*f8a1b7d9SAlexander Kabaev 	    __throw_exception_again;
532*f8a1b7d9SAlexander Kabaev 	  }
533*f8a1b7d9SAlexander Kabaev 	__r->_M_set_length(__len);
534*f8a1b7d9SAlexander Kabaev 	return __r->_M_refdata();
535*f8a1b7d9SAlexander Kabaev       }
536*f8a1b7d9SAlexander Kabaev 
537*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
538*f8a1b7d9SAlexander Kabaev     template<typename _InIterator>
539*f8a1b7d9SAlexander Kabaev       _CharT*
540*f8a1b7d9SAlexander Kabaev       __rc_string_base<_CharT, _Traits, _Alloc>::
_S_construct(_InIterator __beg,_InIterator __end,const _Alloc & __a,std::forward_iterator_tag)541*f8a1b7d9SAlexander Kabaev       _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
542*f8a1b7d9SAlexander Kabaev 		   std::forward_iterator_tag)
543*f8a1b7d9SAlexander Kabaev       {
544*f8a1b7d9SAlexander Kabaev 	if (__beg == __end && __a == _Alloc())
545*f8a1b7d9SAlexander Kabaev 	  return _S_empty_rep._M_refcopy();
546*f8a1b7d9SAlexander Kabaev 
547*f8a1b7d9SAlexander Kabaev 	// NB: Not required, but considered best practice.
548*f8a1b7d9SAlexander Kabaev 	if (__builtin_expect(_S_is_null_pointer(__beg) && __beg != __end, 0))
549*f8a1b7d9SAlexander Kabaev 	  std::__throw_logic_error(__N("__rc_string_base::"
550*f8a1b7d9SAlexander Kabaev 				       "_S_construct NULL not valid"));
551*f8a1b7d9SAlexander Kabaev 
552*f8a1b7d9SAlexander Kabaev 	const size_type __dnew = static_cast<size_type>(std::distance(__beg,
553*f8a1b7d9SAlexander Kabaev 								      __end));
554*f8a1b7d9SAlexander Kabaev 	// Check for out_of_range and length_error exceptions.
555*f8a1b7d9SAlexander Kabaev 	_Rep* __r = _Rep::_S_create(__dnew, size_type(0), __a);
556*f8a1b7d9SAlexander Kabaev 	try
557*f8a1b7d9SAlexander Kabaev 	  { _S_copy_chars(__r->_M_refdata(), __beg, __end); }
558*f8a1b7d9SAlexander Kabaev 	catch(...)
559*f8a1b7d9SAlexander Kabaev 	  {
560*f8a1b7d9SAlexander Kabaev 	    __r->_M_destroy(__a);
561*f8a1b7d9SAlexander Kabaev 	    __throw_exception_again;
562*f8a1b7d9SAlexander Kabaev 	  }
563*f8a1b7d9SAlexander Kabaev 	__r->_M_set_length(__dnew);
564*f8a1b7d9SAlexander Kabaev 	return __r->_M_refdata();
565*f8a1b7d9SAlexander Kabaev       }
566*f8a1b7d9SAlexander Kabaev 
567*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
568*f8a1b7d9SAlexander Kabaev     _CharT*
569*f8a1b7d9SAlexander Kabaev     __rc_string_base<_CharT, _Traits, _Alloc>::
_S_construct(size_type __n,_CharT __c,const _Alloc & __a)570*f8a1b7d9SAlexander Kabaev     _S_construct(size_type __n, _CharT __c, const _Alloc& __a)
571*f8a1b7d9SAlexander Kabaev     {
572*f8a1b7d9SAlexander Kabaev       if (__n == 0 && __a == _Alloc())
573*f8a1b7d9SAlexander Kabaev 	return _S_empty_rep._M_refcopy();
574*f8a1b7d9SAlexander Kabaev 
575*f8a1b7d9SAlexander Kabaev       // Check for out_of_range and length_error exceptions.
576*f8a1b7d9SAlexander Kabaev       _Rep* __r = _Rep::_S_create(__n, size_type(0), __a);
577*f8a1b7d9SAlexander Kabaev       if (__n)
578*f8a1b7d9SAlexander Kabaev 	_S_assign(__r->_M_refdata(), __n, __c);
579*f8a1b7d9SAlexander Kabaev 
580*f8a1b7d9SAlexander Kabaev       __r->_M_set_length(__n);
581*f8a1b7d9SAlexander Kabaev       return __r->_M_refdata();
582*f8a1b7d9SAlexander Kabaev     }
583*f8a1b7d9SAlexander Kabaev 
584*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
585*f8a1b7d9SAlexander Kabaev     void
586*f8a1b7d9SAlexander Kabaev     __rc_string_base<_CharT, _Traits, _Alloc>::
_M_swap(__rc_string_base & __rcs)587*f8a1b7d9SAlexander Kabaev     _M_swap(__rc_string_base& __rcs)
588*f8a1b7d9SAlexander Kabaev     {
589*f8a1b7d9SAlexander Kabaev       if (_M_is_leaked())
590*f8a1b7d9SAlexander Kabaev 	_M_set_sharable();
591*f8a1b7d9SAlexander Kabaev       if (__rcs._M_is_leaked())
592*f8a1b7d9SAlexander Kabaev 	__rcs._M_set_sharable();
593*f8a1b7d9SAlexander Kabaev 
594*f8a1b7d9SAlexander Kabaev       _CharT* __tmp = _M_data();
595*f8a1b7d9SAlexander Kabaev       _M_data(__rcs._M_data());
596*f8a1b7d9SAlexander Kabaev       __rcs._M_data(__tmp);
597*f8a1b7d9SAlexander Kabaev 
598*f8a1b7d9SAlexander Kabaev       // _GLIBCXX_RESOLVE_LIB_DEFECTS
599*f8a1b7d9SAlexander Kabaev       // 431. Swapping containers with unequal allocators.
600*f8a1b7d9SAlexander Kabaev       std::__alloc_swap<allocator_type>::_S_do_it(_M_get_allocator(),
601*f8a1b7d9SAlexander Kabaev 						  __rcs._M_get_allocator());
602*f8a1b7d9SAlexander Kabaev     }
603*f8a1b7d9SAlexander Kabaev 
604*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
605*f8a1b7d9SAlexander Kabaev     void
606*f8a1b7d9SAlexander Kabaev     __rc_string_base<_CharT, _Traits, _Alloc>::
_M_assign(const __rc_string_base & __rcs)607*f8a1b7d9SAlexander Kabaev     _M_assign(const __rc_string_base& __rcs)
608*f8a1b7d9SAlexander Kabaev     {
609*f8a1b7d9SAlexander Kabaev       if (_M_rep() != __rcs._M_rep())
610*f8a1b7d9SAlexander Kabaev 	{
611*f8a1b7d9SAlexander Kabaev 	  _CharT* __tmp = __rcs._M_grab(_M_get_allocator());
612*f8a1b7d9SAlexander Kabaev 	  _M_dispose();
613*f8a1b7d9SAlexander Kabaev 	  _M_data(__tmp);
614*f8a1b7d9SAlexander Kabaev 	}
615*f8a1b7d9SAlexander Kabaev     }
616*f8a1b7d9SAlexander Kabaev 
617*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
618*f8a1b7d9SAlexander Kabaev     void
619*f8a1b7d9SAlexander Kabaev     __rc_string_base<_CharT, _Traits, _Alloc>::
_M_reserve(size_type __res)620*f8a1b7d9SAlexander Kabaev     _M_reserve(size_type __res)
621*f8a1b7d9SAlexander Kabaev     {
622*f8a1b7d9SAlexander Kabaev       // Make sure we don't shrink below the current size.
623*f8a1b7d9SAlexander Kabaev       if (__res < _M_length())
624*f8a1b7d9SAlexander Kabaev 	__res = _M_length();
625*f8a1b7d9SAlexander Kabaev 
626*f8a1b7d9SAlexander Kabaev       if (__res != _M_capacity() || _M_is_shared())
627*f8a1b7d9SAlexander Kabaev 	{
628*f8a1b7d9SAlexander Kabaev 	  _CharT* __tmp = _M_rep()->_M_clone(_M_get_allocator(),
629*f8a1b7d9SAlexander Kabaev 					     __res - _M_length());
630*f8a1b7d9SAlexander Kabaev 	  _M_dispose();
631*f8a1b7d9SAlexander Kabaev 	  _M_data(__tmp);
632*f8a1b7d9SAlexander Kabaev 	}
633*f8a1b7d9SAlexander Kabaev     }
634*f8a1b7d9SAlexander Kabaev 
635*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
636*f8a1b7d9SAlexander Kabaev     void
637*f8a1b7d9SAlexander Kabaev     __rc_string_base<_CharT, _Traits, _Alloc>::
_M_mutate(size_type __pos,size_type __len1,const _CharT * __s,size_type __len2)638*f8a1b7d9SAlexander Kabaev     _M_mutate(size_type __pos, size_type __len1, const _CharT* __s,
639*f8a1b7d9SAlexander Kabaev 	      size_type __len2)
640*f8a1b7d9SAlexander Kabaev     {
641*f8a1b7d9SAlexander Kabaev       const size_type __how_much = _M_length() - __pos - __len1;
642*f8a1b7d9SAlexander Kabaev 
643*f8a1b7d9SAlexander Kabaev       _Rep* __r = _Rep::_S_create(_M_length() + __len2 - __len1,
644*f8a1b7d9SAlexander Kabaev 				  _M_capacity(), _M_get_allocator());
645*f8a1b7d9SAlexander Kabaev 
646*f8a1b7d9SAlexander Kabaev       if (__pos)
647*f8a1b7d9SAlexander Kabaev 	_S_copy(__r->_M_refdata(), _M_data(), __pos);
648*f8a1b7d9SAlexander Kabaev       if (__s && __len2)
649*f8a1b7d9SAlexander Kabaev 	_S_copy(__r->_M_refdata() + __pos, __s, __len2);
650*f8a1b7d9SAlexander Kabaev       if (__how_much)
651*f8a1b7d9SAlexander Kabaev 	_S_copy(__r->_M_refdata() + __pos + __len2,
652*f8a1b7d9SAlexander Kabaev 		_M_data() + __pos + __len1, __how_much);
653*f8a1b7d9SAlexander Kabaev 
654*f8a1b7d9SAlexander Kabaev       _M_dispose();
655*f8a1b7d9SAlexander Kabaev       _M_data(__r->_M_refdata());
656*f8a1b7d9SAlexander Kabaev     }
657*f8a1b7d9SAlexander Kabaev 
658*f8a1b7d9SAlexander Kabaev   template<typename _CharT, typename _Traits, typename _Alloc>
659*f8a1b7d9SAlexander Kabaev     void
660*f8a1b7d9SAlexander Kabaev     __rc_string_base<_CharT, _Traits, _Alloc>::
_M_erase(size_type __pos,size_type __n)661*f8a1b7d9SAlexander Kabaev     _M_erase(size_type __pos, size_type __n)
662*f8a1b7d9SAlexander Kabaev     {
663*f8a1b7d9SAlexander Kabaev       const size_type __new_size = _M_length() - __n;
664*f8a1b7d9SAlexander Kabaev       const size_type __how_much = _M_length() - __pos - __n;
665*f8a1b7d9SAlexander Kabaev 
666*f8a1b7d9SAlexander Kabaev       if (_M_is_shared())
667*f8a1b7d9SAlexander Kabaev 	{
668*f8a1b7d9SAlexander Kabaev 	  // Must reallocate.
669*f8a1b7d9SAlexander Kabaev 	  _Rep* __r = _Rep::_S_create(__new_size, _M_capacity(),
670*f8a1b7d9SAlexander Kabaev 				      _M_get_allocator());
671*f8a1b7d9SAlexander Kabaev 
672*f8a1b7d9SAlexander Kabaev 	  if (__pos)
673*f8a1b7d9SAlexander Kabaev 	    _S_copy(__r->_M_refdata(), _M_data(), __pos);
674*f8a1b7d9SAlexander Kabaev 	  if (__how_much)
675*f8a1b7d9SAlexander Kabaev 	    _S_copy(__r->_M_refdata() + __pos,
676*f8a1b7d9SAlexander Kabaev 		    _M_data() + __pos + __n, __how_much);
677*f8a1b7d9SAlexander Kabaev 
678*f8a1b7d9SAlexander Kabaev 	  _M_dispose();
679*f8a1b7d9SAlexander Kabaev 	  _M_data(__r->_M_refdata());
680*f8a1b7d9SAlexander Kabaev 	}
681*f8a1b7d9SAlexander Kabaev       else if (__how_much && __n)
682*f8a1b7d9SAlexander Kabaev 	{
683*f8a1b7d9SAlexander Kabaev 	  // Work in-place.
684*f8a1b7d9SAlexander Kabaev 	  _S_move(_M_data() + __pos,
685*f8a1b7d9SAlexander Kabaev 		  _M_data() + __pos + __n, __how_much);
686*f8a1b7d9SAlexander Kabaev 	}
687*f8a1b7d9SAlexander Kabaev 
688*f8a1b7d9SAlexander Kabaev       _M_rep()->_M_set_length(__new_size);
689*f8a1b7d9SAlexander Kabaev     }
690*f8a1b7d9SAlexander Kabaev 
691*f8a1b7d9SAlexander Kabaev   template<>
692*f8a1b7d9SAlexander Kabaev     inline bool
693*f8a1b7d9SAlexander Kabaev     __rc_string_base<char, std::char_traits<char>,
694*f8a1b7d9SAlexander Kabaev 		     std::allocator<char> >::
_M_compare(const __rc_string_base & __rcs)695*f8a1b7d9SAlexander Kabaev     _M_compare(const __rc_string_base& __rcs) const
696*f8a1b7d9SAlexander Kabaev     {
697*f8a1b7d9SAlexander Kabaev       if (_M_rep() == __rcs._M_rep())
698*f8a1b7d9SAlexander Kabaev 	return true;
699*f8a1b7d9SAlexander Kabaev       return false;
700*f8a1b7d9SAlexander Kabaev     }
701*f8a1b7d9SAlexander Kabaev 
702*f8a1b7d9SAlexander Kabaev #ifdef _GLIBCXX_USE_WCHAR_T
703*f8a1b7d9SAlexander Kabaev   template<>
704*f8a1b7d9SAlexander Kabaev     inline bool
705*f8a1b7d9SAlexander Kabaev     __rc_string_base<wchar_t, std::char_traits<wchar_t>,
706*f8a1b7d9SAlexander Kabaev 		     std::allocator<wchar_t> >::
_M_compare(const __rc_string_base & __rcs)707*f8a1b7d9SAlexander Kabaev     _M_compare(const __rc_string_base& __rcs) const
708*f8a1b7d9SAlexander Kabaev     {
709*f8a1b7d9SAlexander Kabaev       if (_M_rep() == __rcs._M_rep())
710*f8a1b7d9SAlexander Kabaev 	return true;
711*f8a1b7d9SAlexander Kabaev       return false;
712*f8a1b7d9SAlexander Kabaev     }
713*f8a1b7d9SAlexander Kabaev #endif
714*f8a1b7d9SAlexander Kabaev 
715*f8a1b7d9SAlexander Kabaev _GLIBCXX_END_NAMESPACE
716*f8a1b7d9SAlexander Kabaev 
717*f8a1b7d9SAlexander Kabaev #endif /* _RC_STRING_BASE_H */
718