# basic_string.tcc

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    00001 // Components for manipulating sequences of characters -*- C++ -*-
    00002
    00003 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
    00004 // 2006, 2007, 2008, 2009
    00005 // Free Software Foundation, Inc.
    00006 //
    00007 // This file is part of the GNU ISO C++ Library.  This library is free
    00008 // software; you can redistribute it and/or modify it under the
    00009 // terms of the GNU General Public License as published by the
    00010 // Free Software Foundation; either version 3, or (at your option)
    00011 // any later version.
    00012
    00013 // This library is distributed in the hope that it will be useful,
    00014 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00015 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    00016 // GNU General Public License for more details.
    00017
    00018 // Under Section 7 of GPL version 3, you are granted additional
    00019 // permissions described in the GCC Runtime Library Exception, version
    00020 // 3.1, as published by the Free Software Foundation.
    00021
    00022 // You should have received a copy of the GNU General Public License and
    00023 // a copy of the GCC Runtime Library Exception along with this program;
    00024 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
    00025 // <http://www.gnu.org/licenses/>.
    00026
    00027 /** @file basic_string.tcc
    00028  *  This is an internal header file, included by other library headers.
    00029  *  You should not attempt to use it directly.
    00030  */
    00031
    00032 //
    00033 // ISO C++ 14882: 21  Strings library
    00034 //
    00035
    00036 // Written by Jason Merrill based upon the specification by Takanori Adachi
    00037 // in ANSI X3J16/94-0013R2.  Rewritten by Nathan Myers to ISO-14882.
    00038
    00039 #ifndef _BASIC_STRING_TCC
    00040 #define _BASIC_STRING_TCC 1
    00041
    00042 #pragma GCC system_header
    00043
    00044 #include <cxxabi-forced.h>
    00045
    00046 _GLIBCXX_BEGIN_NAMESPACE(std)
    00047
    00048   template<typename _CharT, typename _Traits, typename _Alloc>
    00049     const typename basic_string<_CharT, _Traits, _Alloc>::size_type
    00050     basic_string<_CharT, _Traits, _Alloc>::
    00051     _Rep::_S_max_size = (((npos - sizeof(_Rep_base))/sizeof(_CharT)) - 1) / 4;
    00052
    00053   template<typename _CharT, typename _Traits, typename _Alloc>
    00054     const _CharT
    00055     basic_string<_CharT, _Traits, _Alloc>::
    00056     _Rep::_S_terminal = _CharT();
    00057
    00058   template<typename _CharT, typename _Traits, typename _Alloc>
    00059     const typename basic_string<_CharT, _Traits, _Alloc>::size_type
    00060     basic_string<_CharT, _Traits, _Alloc>::npos;
    00061
    00062   // Linker sets _S_empty_rep_storage to all 0s (one reference, empty string)
    00063   // at static init time (before static ctors are run).
    00064   template<typename _CharT, typename _Traits, typename _Alloc>
    00065     typename basic_string<_CharT, _Traits, _Alloc>::size_type
    00066     basic_string<_CharT, _Traits, _Alloc>::_Rep::_S_empty_rep_storage[
    00067     (sizeof(_Rep_base) + sizeof(_CharT) + sizeof(size_type) - 1) /
    00068       sizeof(size_type)];
    00069
    00070   // NB: This is the special case for Input Iterators, used in
    00071   // istreambuf_iterators, etc.
    00072   // Input Iterators have a cost structure very different from
    00073   // pointers, calling for a different coding style.
    00074   template<typename _CharT, typename _Traits, typename _Alloc>
    00075     template<typename _InIterator>
    00076       _CharT*
    00077       basic_string<_CharT, _Traits, _Alloc>::
    00078       _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
    00079            input_iterator_tag)
    00080       {
    00081 #ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
    00082     if (__beg == __end && __a == _Alloc())
    00083       return _S_empty_rep()._M_refdata();
    00084 #endif
    00085     // Avoid reallocation for common case.
    00086     _CharT __buf[128];
    00087     size_type __len = 0;
    00088     while (__beg != __end && __len < sizeof(__buf) / sizeof(_CharT))
    00089       {
    00090         __buf[__len++] = *__beg;
    00091         ++__beg;
    00092       }
    00093     _Rep* __r = _Rep::_S_create(__len, size_type(0), __a);
    00094     _M_copy(__r->_M_refdata(), __buf, __len);
    00095     __try
    00096       {
    00097         while (__beg != __end)
    00098           {
    00099         if (__len == __r->_M_capacity)
    00100           {
    00101             // Allocate more space.
    00102             _Rep* __another = _Rep::_S_create(__len + 1, __len, __a);
    00103             _M_copy(__another->_M_refdata(), __r->_M_refdata(), __len);
    00104             __r->_M_destroy(__a);
    00105             __r = __another;
    00106           }
    00107         __r->_M_refdata()[__len++] = *__beg;
    00108         ++__beg;
    00109           }
    00110       }
    00111     __catch(...)
    00112       {
    00113         __r->_M_destroy(__a);
    00114         __throw_exception_again;
    00115       }
    00116     __r->_M_set_length_and_sharable(__len);
    00117     return __r->_M_refdata();
    00118       }
    00119
    00120   template<typename _CharT, typename _Traits, typename _Alloc>
    00121     template <typename _InIterator>
    00122       _CharT*
    00123       basic_string<_CharT, _Traits, _Alloc>::
    00124       _S_construct(_InIterator __beg, _InIterator __end, const _Alloc& __a,
    00125            forward_iterator_tag)
    00126       {
    00127 #ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
    00128     if (__beg == __end && __a == _Alloc())
    00129       return _S_empty_rep()._M_refdata();
    00130 #endif
    00131     // NB: Not required, but considered best practice.
    00132     if (__gnu_cxx::__is_null_pointer(__beg) && __beg != __end)
    00133       __throw_logic_error(__N("basic_string::_S_construct NULL not valid"));
    00134
    00135     const size_type __dnew = static_cast<size_type>(std::distance(__beg,
    00136                                       __end));
    00137     // Check for out_of_range and length_error exceptions.
    00138     _Rep* __r = _Rep::_S_create(__dnew, size_type(0), __a);
    00139     __try
    00140       { _S_copy_chars(__r->_M_refdata(), __beg, __end); }
    00141     __catch(...)
    00142       {
    00143         __r->_M_destroy(__a);
    00144         __throw_exception_again;
    00145       }
    00146     __r->_M_set_length_and_sharable(__dnew);
    00147     return __r->_M_refdata();
    00148       }
    00149
    00150   template<typename _CharT, typename _Traits, typename _Alloc>
    00151     _CharT*
    00152     basic_string<_CharT, _Traits, _Alloc>::
    00153     _S_construct(size_type __n, _CharT __c, const _Alloc& __a)
    00154     {
    00155 #ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
    00156       if (__n == 0 && __a == _Alloc())
    00157     return _S_empty_rep()._M_refdata();
    00158 #endif
    00159       // Check for out_of_range and length_error exceptions.
    00160       _Rep* __r = _Rep::_S_create(__n, size_type(0), __a);
    00161       if (__n)
    00162     _M_assign(__r->_M_refdata(), __n, __c);
    00163
    00164       __r->_M_set_length_and_sharable(__n);
    00165       return __r->_M_refdata();
    00166     }
    00167
    00168   template<typename _CharT, typename _Traits, typename _Alloc>
    00169     basic_string<_CharT, _Traits, _Alloc>::
    00170     basic_string(const basic_string& __str)
    00171     : _M_dataplus(__str._M_rep()->_M_grab(_Alloc(__str.get_allocator()),
    00172                       __str.get_allocator()),
    00173           __str.get_allocator())
    00174     { }
    00175
    00176   template<typename _CharT, typename _Traits, typename _Alloc>
    00177     basic_string<_CharT, _Traits, _Alloc>::
    00178     basic_string(const _Alloc& __a)
    00179     : _M_dataplus(_S_construct(size_type(), _CharT(), __a), __a)
    00180     { }
    00181
    00182   template<typename _CharT, typename _Traits, typename _Alloc>
    00183     basic_string<_CharT, _Traits, _Alloc>::
    00184     basic_string(const basic_string& __str, size_type __pos, size_type __n)
    00185     : _M_dataplus(_S_construct(__str._M_data()
    00186                    + __str._M_check(__pos,
    00187                         "basic_string::basic_string"),
    00188                    __str._M_data() + __str._M_limit(__pos, __n)
    00189                    + __pos, _Alloc()), _Alloc())
    00190     { }
    00191
    00192   template<typename _CharT, typename _Traits, typename _Alloc>
    00193     basic_string<_CharT, _Traits, _Alloc>::
    00194     basic_string(const basic_string& __str, size_type __pos,
    00195          size_type __n, const _Alloc& __a)
    00196     : _M_dataplus(_S_construct(__str._M_data()
    00197                    + __str._M_check(__pos,
    00198                         "basic_string::basic_string"),
    00199                    __str._M_data() + __str._M_limit(__pos, __n)
    00200                    + __pos, __a), __a)
    00201     { }
    00202
    00203   // TBD: DPG annotate
    00204   template<typename _CharT, typename _Traits, typename _Alloc>
    00205     basic_string<_CharT, _Traits, _Alloc>::
    00206     basic_string(const _CharT* __s, size_type __n, const _Alloc& __a)
    00207     : _M_dataplus(_S_construct(__s, __s + __n, __a), __a)
    00208     { }
    00209
    00210   // TBD: DPG annotate
    00211   template<typename _CharT, typename _Traits, typename _Alloc>
    00212     basic_string<_CharT, _Traits, _Alloc>::
    00213     basic_string(const _CharT* __s, const _Alloc& __a)
    00214     : _M_dataplus(_S_construct(__s, __s ? __s + traits_type::length(__s) :
    00215                    __s + npos, __a), __a)
    00216     { }
    00217
    00218   template<typename _CharT, typename _Traits, typename _Alloc>
    00219     basic_string<_CharT, _Traits, _Alloc>::
    00220     basic_string(size_type __n, _CharT __c, const _Alloc& __a)
    00221     : _M_dataplus(_S_construct(__n, __c, __a), __a)
    00222     { }
    00223
    00224   // TBD: DPG annotate
    00225   template<typename _CharT, typename _Traits, typename _Alloc>
    00226     template<typename _InputIterator>
    00227     basic_string<_CharT, _Traits, _Alloc>::
    00228     basic_string(_InputIterator __beg, _InputIterator __end, const _Alloc& __a)
    00229     : _M_dataplus(_S_construct(__beg, __end, __a), __a)
    00230     { }
    00231
    00232 #ifdef __GXX_EXPERIMENTAL_CXX0X__
    00233   template<typename _CharT, typename _Traits, typename _Alloc>
    00234     basic_string<_CharT, _Traits, _Alloc>::
    00235     basic_string(initializer_list<_CharT> __l, const _Alloc& __a)
    00236     : _M_dataplus(_S_construct(__l.begin(), __l.end(), __a), __a)
    00237     { }
    00238 #endif
    00239
    00240   template<typename _CharT, typename _Traits, typename _Alloc>
    00241     basic_string<_CharT, _Traits, _Alloc>&
    00242     basic_string<_CharT, _Traits, _Alloc>::
    00243     assign(const basic_string& __str)
    00244     {
    00245       if (_M_rep() != __str._M_rep())
    00246     {
    00247       // XXX MT
    00248       const allocator_type __a = this->get_allocator();
    00249       _CharT* __tmp = __str._M_rep()->_M_grab(__a, __str.get_allocator());
    00250       _M_rep()->_M_dispose(__a);
    00251       _M_data(__tmp);
    00252     }
    00253       return *this;
    00254     }
    00255
    00256   template<typename _CharT, typename _Traits, typename _Alloc>
    00257     basic_string<_CharT, _Traits, _Alloc>&
    00258     basic_string<_CharT, _Traits, _Alloc>::
    00259     assign(const _CharT* __s, size_type __n)
    00260     {
    00261       __glibcxx_requires_string_len(__s, __n);
    00262       _M_check_length(this->size(), __n, "basic_string::assign");
    00263       if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
    00264     return _M_replace_safe(size_type(0), this->size(), __s, __n);
    00265       else
    00266     {
    00267       // Work in-place.
    00268       const size_type __pos = __s - _M_data();
    00269       if (__pos >= __n)
    00270         _M_copy(_M_data(), __s, __n);
    00271       else if (__pos)
    00272         _M_move(_M_data(), __s, __n);
    00273       _M_rep()->_M_set_length_and_sharable(__n);
    00274       return *this;
    00275     }
    00276      }
    00277
    00278   template<typename _CharT, typename _Traits, typename _Alloc>
    00279     basic_string<_CharT, _Traits, _Alloc>&
    00280     basic_string<_CharT, _Traits, _Alloc>::
    00281     append(size_type __n, _CharT __c)
    00282     {
    00283       if (__n)
    00284     {
    00285       _M_check_length(size_type(0), __n, "basic_string::append");
    00286       const size_type __len = __n + this->size();
    00287       if (__len > this->capacity() || _M_rep()->_M_is_shared())
    00288         this->reserve(__len);
    00289       _M_assign(_M_data() + this->size(), __n, __c);
    00290       _M_rep()->_M_set_length_and_sharable(__len);
    00291     }
    00292       return *this;
    00293     }
    00294
    00295   template<typename _CharT, typename _Traits, typename _Alloc>
    00296     basic_string<_CharT, _Traits, _Alloc>&
    00297     basic_string<_CharT, _Traits, _Alloc>::
    00298     append(const _CharT* __s, size_type __n)
    00299     {
    00300       __glibcxx_requires_string_len(__s, __n);
    00301       if (__n)
    00302     {
    00303       _M_check_length(size_type(0), __n, "basic_string::append");
    00304       const size_type __len = __n + this->size();
    00305       if (__len > this->capacity() || _M_rep()->_M_is_shared())
    00306         {
    00307           if (_M_disjunct(__s))
    00308         this->reserve(__len);
    00309           else
    00310         {
    00311           const size_type __off = __s - _M_data();
    00312           this->reserve(__len);
    00313           __s = _M_data() + __off;
    00314         }
    00315         }
    00316       _M_copy(_M_data() + this->size(), __s, __n);
    00317       _M_rep()->_M_set_length_and_sharable(__len);
    00318     }
    00319       return *this;
    00320     }
    00321
    00322   template<typename _CharT, typename _Traits, typename _Alloc>
    00323     basic_string<_CharT, _Traits, _Alloc>&
    00324     basic_string<_CharT, _Traits, _Alloc>::
    00325     append(const basic_string& __str)
    00326     {
    00327       const size_type __size = __str.size();
    00328       if (__size)
    00329     {
    00330       const size_type __len = __size + this->size();
    00331       if (__len > this->capacity() || _M_rep()->_M_is_shared())
    00332         this->reserve(__len);
    00333       _M_copy(_M_data() + this->size(), __str._M_data(), __size);
    00334       _M_rep()->_M_set_length_and_sharable(__len);
    00335     }
    00336       return *this;
    00337     }
    00338
    00339   template<typename _CharT, typename _Traits, typename _Alloc>
    00340     basic_string<_CharT, _Traits, _Alloc>&
    00341     basic_string<_CharT, _Traits, _Alloc>::
    00342     append(const basic_string& __str, size_type __pos, size_type __n)
    00343     {
    00344       __str._M_check(__pos, "basic_string::append");
    00345       __n = __str._M_limit(__pos, __n);
    00346       if (__n)
    00347     {
    00348       const size_type __len = __n + this->size();
    00349       if (__len > this->capacity() || _M_rep()->_M_is_shared())
    00350         this->reserve(__len);
    00351       _M_copy(_M_data() + this->size(), __str._M_data() + __pos, __n);
    00352       _M_rep()->_M_set_length_and_sharable(__len);
    00353     }
    00354       return *this;
    00355     }
    00356
    00357    template<typename _CharT, typename _Traits, typename _Alloc>
    00358      basic_string<_CharT, _Traits, _Alloc>&
    00359      basic_string<_CharT, _Traits, _Alloc>::
    00360      insert(size_type __pos, const _CharT* __s, size_type __n)
    00361      {
    00362        __glibcxx_requires_string_len(__s, __n);
    00363        _M_check(__pos, "basic_string::insert");
    00364        _M_check_length(size_type(0), __n, "basic_string::insert");
    00365        if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
    00366          return _M_replace_safe(__pos, size_type(0), __s, __n);
    00367        else
    00368          {
    00369            // Work in-place.
    00370            const size_type __off = __s - _M_data();
    00371            _M_mutate(__pos, 0, __n);
    00372            __s = _M_data() + __off;
    00373            _CharT* __p = _M_data() + __pos;
    00374            if (__s  + __n <= __p)
    00375              _M_copy(__p, __s, __n);
    00376            else if (__s >= __p)
    00377              _M_copy(__p, __s + __n, __n);
    00378            else
    00379              {
    00380            const size_type __nleft = __p - __s;
    00381                _M_copy(__p, __s, __nleft);
    00382                _M_copy(__p + __nleft, __p + __n, __n - __nleft);
    00383              }
    00384            return *this;
    00385          }
    00386      }
    00387
    00388    template<typename _CharT, typename _Traits, typename _Alloc>
    00389      typename basic_string<_CharT, _Traits, _Alloc>::iterator
    00390      basic_string<_CharT, _Traits, _Alloc>::
    00391      erase(iterator __first, iterator __last)
    00392      {
    00393        _GLIBCXX_DEBUG_PEDASSERT(__first >= _M_ibegin() && __first <= __last
    00394                 && __last <= _M_iend());
    00395
    00396        // NB: This isn't just an optimization (bail out early when
    00397        // there is nothing to do, really), it's also a correctness
    00398        // issue vs MT, see libstdc++/40518.
    00399        const size_type __size = __last - __first;
    00400        if (__size)
    00401      {
    00402        const size_type __pos = __first - _M_ibegin();
    00403        _M_mutate(__pos, __size, size_type(0));
    00404        _M_rep()->_M_set_leaked();
    00405        return iterator(_M_data() + __pos);
    00406      }
    00407        else
    00408      return __first;
    00409      }
    00410
    00411    template<typename _CharT, typename _Traits, typename _Alloc>
    00412      basic_string<_CharT, _Traits, _Alloc>&
    00413      basic_string<_CharT, _Traits, _Alloc>::
    00414      replace(size_type __pos, size_type __n1, const _CharT* __s,
    00415          size_type __n2)
    00416      {
    00417        __glibcxx_requires_string_len(__s, __n2);
    00418        _M_check(__pos, "basic_string::replace");
    00419        __n1 = _M_limit(__pos, __n1);
    00420        _M_check_length(__n1, __n2, "basic_string::replace");
    00421        bool __left;
    00422        if (_M_disjunct(__s) || _M_rep()->_M_is_shared())
    00423          return _M_replace_safe(__pos, __n1, __s, __n2);
    00424        else if ((__left = __s + __n2 <= _M_data() + __pos)
    00425         || _M_data() + __pos + __n1 <= __s)
    00426      {
    00427        // Work in-place: non-overlapping case.
    00428        size_type __off = __s - _M_data();
    00429        __left ? __off : (__off += __n2 - __n1);
    00430        _M_mutate(__pos, __n1, __n2);
    00431        _M_copy(_M_data() + __pos, _M_data() + __off, __n2);
    00432        return *this;
    00433      }
    00434        else
    00435      {
    00436        // Todo: overlapping case.
    00437        const basic_string __tmp(__s, __n2);
    00438        return _M_replace_safe(__pos, __n1, __tmp._M_data(), __n2);
    00439      }
    00440      }
    00441
    00442   template<typename _CharT, typename _Traits, typename _Alloc>
    00443     void
    00444     basic_string<_CharT, _Traits, _Alloc>::_Rep::
    00445     _M_destroy(const _Alloc& __a) throw ()
    00446     {
    00447       const size_type __size = sizeof(_Rep_base) +
    00448                            (this->_M_capacity + 1) * sizeof(_CharT);
    00449       _Raw_bytes_alloc(__a).deallocate(reinterpret_cast<char*>(this), __size);
    00450     }
    00451
    00452   template<typename _CharT, typename _Traits, typename _Alloc>
    00453     void
    00454     basic_string<_CharT, _Traits, _Alloc>::
    00455     _M_leak_hard()
    00456     {
    00457 #ifndef _GLIBCXX_FULLY_DYNAMIC_STRING
    00458       if (_M_rep() == &_S_empty_rep())
    00459     return;
    00460 #endif
    00461       if (_M_rep()->_M_is_shared())
    00462     _M_mutate(0, 0, 0);
    00463       _M_rep()->_M_set_leaked();
    00464     }
    00465
    00466   template<typename _CharT, typename _Traits, typename _Alloc>
    00467     void
    00468     basic_string<_CharT, _Traits, _Alloc>::
    00469     _M_mutate(size_type __pos, size_type __len1, size_type __len2)
    00470     {
    00471       const size_type __old_size = this->size();
    00472       const size_type __new_size = __old_size + __len2 - __len1;
    00473       const size_type __how_much = __old_size - __pos - __len1;
    00474
    00475       if (__new_size > this->capacity() || _M_rep()->_M_is_shared())
    00476     {
    00477       // Must reallocate.
    00478       const allocator_type __a = get_allocator();
    00479       _Rep* __r = _Rep::_S_create(__new_size, this->capacity(), __a);
    00480
    00481       if (__pos)
    00482         _M_copy(__r->_M_refdata(), _M_data(), __pos);
    00483       if (__how_much)
    00484         _M_copy(__r->_M_refdata() + __pos + __len2,
    00485             _M_data() + __pos + __len1, __how_much);
    00486
    00487       _M_rep()->_M_dispose(__a);
    00488       _M_data(__r->_M_refdata());
    00489     }
    00490       else if (__how_much && __len1 != __len2)
    00491     {
    00492       // Work in-place.
    00493       _M_move(_M_data() + __pos + __len2,
    00494           _M_data() + __pos + __len1, __how_much);
    00495     }
    00496       _M_rep()->_M_set_length_and_sharable(__new_size);
    00497     }
    00498
    00499   template<typename _CharT, typename _Traits, typename _Alloc>
    00500     void
    00501     basic_string<_CharT, _Traits, _Alloc>::
    00502     reserve(size_type __res)
    00503     {
    00504       if (__res != this->capacity() || _M_rep()->_M_is_shared())
    00505         {
    00506       // Make sure we don't shrink below the current size
    00507       if (__res < this->size())
    00508         __res = this->size();
    00509       const allocator_type __a = get_allocator();
    00510       _CharT* __tmp = _M_rep()->_M_clone(__a, __res - this->size());
    00511       _M_rep()->_M_dispose(__a);
    00512       _M_data(__tmp);
    00513         }
    00514     }
    00515
    00516   template<typename _CharT, typename _Traits, typename _Alloc>
    00517     void
    00518     basic_string<_CharT, _Traits, _Alloc>::
    00519     swap(basic_string& __s)
    00520     {
    00521       if (_M_rep()->_M_is_leaked())
    00522     _M_rep()->_M_set_sharable();
    00523       if (__s._M_rep()->_M_is_leaked())
    00524     __s._M_rep()->_M_set_sharable();
    00525       if (this->get_allocator() == __s.get_allocator())
    00526     {
    00527       _CharT* __tmp = _M_data();
    00528       _M_data(__s._M_data());
    00529       __s._M_data(__tmp);
    00530     }
    00531       // The code below can usually be optimized away.
    00532       else
    00533     {
    00534       const basic_string __tmp1(_M_ibegin(), _M_iend(),
    00535                     __s.get_allocator());
    00536       const basic_string __tmp2(__s._M_ibegin(), __s._M_iend(),
    00537                     this->get_allocator());
    00538       *this = __tmp2;
    00539       __s = __tmp1;
    00540     }
    00541     }
    00542
    00543   template<typename _CharT, typename _Traits, typename _Alloc>
    00544     typename basic_string<_CharT, _Traits, _Alloc>::_Rep*
    00545     basic_string<_CharT, _Traits, _Alloc>::_Rep::
    00546     _S_create(size_type __capacity, size_type __old_capacity,
    00547           const _Alloc& __alloc)
    00548     {
    00549       // _GLIBCXX_RESOLVE_LIB_DEFECTS
    00550       // 83.  String::npos vs. string::max_size()
    00551       if (__capacity > _S_max_size)
    00552     __throw_length_error(__N("basic_string::_S_create"));
    00553
    00554       // The standard places no restriction on allocating more memory
    00555       // than is strictly needed within this layer at the moment or as
    00556       // requested by an explicit application call to reserve().
    00557
    00558       // Many malloc implementations perform quite poorly when an
    00559       // application attempts to allocate memory in a stepwise fashion
    00560       // growing each allocation size by only 1 char.  Additionally,
    00561       // it makes little sense to allocate less linear memory than the
    00562       // natural blocking size of the malloc implementation.
    00563       // Unfortunately, we would need a somewhat low-level calculation
    00564       // with tuned parameters to get this perfect for any particular
    00565       // malloc implementation.  Fortunately, generalizations about
    00566       // common features seen among implementations seems to suffice.
    00567
    00568       // __pagesize need not match the actual VM page size for good
    00569       // results in practice, thus we pick a common value on the low
    00570       // side.  __malloc_header_size is an estimate of the amount of
    00571       // overhead per memory allocation (in practice seen N * sizeof
    00572       // (void*) where N is 0, 2 or 4).  According to folklore,
    00573       // picking this value on the high side is better than
    00574       // low-balling it (especially when this algorithm is used with
    00575       // malloc implementations that allocate memory blocks rounded up
    00576       // to a size which is a power of 2).
    00577       const size_type __pagesize = 4096;
    00578       const size_type __malloc_header_size = 4 * sizeof(void*);
    00579
    00580       // The below implements an exponential growth policy, necessary to
    00581       // meet amortized linear time requirements of the library: see
    00582       // http://gcc.gnu.org/ml/libstdc++/2001-07/msg00085.html.
    00583       // It's active for allocations requiring an amount of memory above
    00584       // system pagesize. This is consistent with the requirements of the
    00585       // standard: http://gcc.gnu.org/ml/libstdc++/2001-07/msg00130.html
    00586       if (__capacity > __old_capacity && __capacity < 2 * __old_capacity)
    00587     __capacity = 2 * __old_capacity;
    00588
    00589       // NB: Need an array of char_type[__capacity], plus a terminating
    00590       // null char_type() element, plus enough for the _Rep data structure.
    00591       // Whew. Seemingly so needy, yet so elemental.
    00592       size_type __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);
    00593
    00594       const size_type __adj_size = __size + __malloc_header_size;
    00595       if (__adj_size > __pagesize && __capacity > __old_capacity)
    00596     {
    00597       const size_type __extra = __pagesize - __adj_size % __pagesize;
    00598       __capacity += __extra / sizeof(_CharT);
    00599       // Never allocate a string bigger than _S_max_size.
    00600       if (__capacity > _S_max_size)
    00601         __capacity = _S_max_size;
    00602       __size = (__capacity + 1) * sizeof(_CharT) + sizeof(_Rep);
    00603     }
    00604
    00605       // NB: Might throw, but no worries about a leak, mate: _Rep()
    00606       // does not throw.
    00607       void* __place = _Raw_bytes_alloc(__alloc).allocate(__size);
    00608       _Rep *__p = new (__place) _Rep;
    00609       __p->_M_capacity = __capacity;
    00610       // ABI compatibility - 3.4.x set in _S_create both
    00611       // _M_refcount and _M_length.  All callers of _S_create
    00612       // in basic_string.tcc then set just _M_length.
    00613       // In 4.0.x and later both _M_refcount and _M_length
    00614       // are initialized in the callers, unfortunately we can
    00615       // have 3.4.x compiled code with _S_create callers inlined
    00616       // calling 4.0.x+ _S_create.
    00617       __p->_M_set_sharable();
    00618       return __p;
    00619     }
    00620
    00621   template<typename _CharT, typename _Traits, typename _Alloc>
    00622     _CharT*
    00623     basic_string<_CharT, _Traits, _Alloc>::_Rep::
    00624     _M_clone(const _Alloc& __alloc, size_type __res)
    00625     {
    00626       // Requested capacity of the clone.
    00627       const size_type __requested_cap = this->_M_length + __res;
    00628       _Rep* __r = _Rep::_S_create(__requested_cap, this->_M_capacity,
    00629                   __alloc);
    00630       if (this->_M_length)
    00631     _M_copy(__r->_M_refdata(), _M_refdata(), this->_M_length);
    00632
    00633       __r->_M_set_length_and_sharable(this->_M_length);
    00634       return __r->_M_refdata();
    00635     }
    00636
    00637   template<typename _CharT, typename _Traits, typename _Alloc>
    00638     void
    00639     basic_string<_CharT, _Traits, _Alloc>::
    00640     resize(size_type __n, _CharT __c)
    00641     {
    00642       const size_type __size = this->size();
    00643       _M_check_length(__size, __n, "basic_string::resize");
    00644       if (__size < __n)
    00645     this->append(__n - __size, __c);
    00646       else if (__n < __size)
    00647     this->erase(__n);
    00648       // else nothing (in particular, avoid calling _M_mutate() unnecessarily.)
    00649     }
    00650
    00651   template<typename _CharT, typename _Traits, typename _Alloc>
    00652     template<typename _InputIterator>
    00653       basic_string<_CharT, _Traits, _Alloc>&
    00654       basic_string<_CharT, _Traits, _Alloc>::
    00655       _M_replace_dispatch(iterator __i1, iterator __i2, _InputIterator __k1,
    00656               _InputIterator __k2, __false_type)
    00657       {
    00658     const basic_string __s(__k1, __k2);
    00659     const size_type __n1 = __i2 - __i1;
    00660     _M_check_length(__n1, __s.size(), "basic_string::_M_replace_dispatch");
    00661     return _M_replace_safe(__i1 - _M_ibegin(), __n1, __s._M_data(),
    00662                    __s.size());
    00663       }
    00664
    00665   template<typename _CharT, typename _Traits, typename _Alloc>
    00666     basic_string<_CharT, _Traits, _Alloc>&
    00667     basic_string<_CharT, _Traits, _Alloc>::
    00668     _M_replace_aux(size_type __pos1, size_type __n1, size_type __n2,
    00669            _CharT __c)
    00670     {
    00671       _M_check_length(__n1, __n2, "basic_string::_M_replace_aux");
    00672       _M_mutate(__pos1, __n1, __n2);
    00673       if (__n2)
    00674     _M_assign(_M_data() + __pos1, __n2, __c);
    00675       return *this;
    00676     }
    00677
    00678   template<typename _CharT, typename _Traits, typename _Alloc>
    00679     basic_string<_CharT, _Traits, _Alloc>&
    00680     basic_string<_CharT, _Traits, _Alloc>::
    00681     _M_replace_safe(size_type __pos1, size_type __n1, const _CharT* __s,
    00682             size_type __n2)
    00683     {
    00684       _M_mutate(__pos1, __n1, __n2);
    00685       if (__n2)
    00686     _M_copy(_M_data() + __pos1, __s, __n2);
    00687       return *this;
    00688     }
    00689
    00690   template<typename _CharT, typename _Traits, typename _Alloc>
    00691     basic_string<_CharT, _Traits, _Alloc>
    00692     operator+(const _CharT* __lhs,
    00693           const basic_string<_CharT, _Traits, _Alloc>& __rhs)
    00694     {
    00695       __glibcxx_requires_string(__lhs);
    00696       typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
    00697       typedef typename __string_type::size_type   __size_type;
    00698       const __size_type __len = _Traits::length(__lhs);
    00699       __string_type __str;
    00700       __str.reserve(__len + __rhs.size());
    00701       __str.append(__lhs, __len);
    00702       __str.append(__rhs);
    00703       return __str;
    00704     }
    00705
    00706   template<typename _CharT, typename _Traits, typename _Alloc>
    00707     basic_string<_CharT, _Traits, _Alloc>
    00708     operator+(_CharT __lhs, const basic_string<_CharT, _Traits, _Alloc>& __rhs)
    00709     {
    00710       typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
    00711       typedef typename __string_type::size_type   __size_type;
    00712       __string_type __str;
    00713       const __size_type __len = __rhs.size();
    00714       __str.reserve(__len + 1);
    00715       __str.append(__size_type(1), __lhs);
    00716       __str.append(__rhs);
    00717       return __str;
    00718     }
    00719
    00720   template<typename _CharT, typename _Traits, typename _Alloc>
    00721     typename basic_string<_CharT, _Traits, _Alloc>::size_type
    00722     basic_string<_CharT, _Traits, _Alloc>::
    00723     copy(_CharT* __s, size_type __n, size_type __pos) const
    00724     {
    00725       _M_check(__pos, "basic_string::copy");
    00726       __n = _M_limit(__pos, __n);
    00727       __glibcxx_requires_string_len(__s, __n);
    00728       if (__n)
    00729     _M_copy(__s, _M_data() + __pos, __n);
    00730       // 21.3.5.7 par 3: do not append null.  (good.)
    00731       return __n;
    00732     }
    00733
    00734   template<typename _CharT, typename _Traits, typename _Alloc>
    00735     typename basic_string<_CharT, _Traits, _Alloc>::size_type
    00736     basic_string<_CharT, _Traits, _Alloc>::
    00737     find(const _CharT* __s, size_type __pos, size_type __n) const
    00738     {
    00739       __glibcxx_requires_string_len(__s, __n);
    00740       const size_type __size = this->size();
    00741       const _CharT* __data = _M_data();
    00742
    00743       if (__n == 0)
    00744     return __pos <= __size ? __pos : npos;
    00745
    00746       if (__n <= __size)
    00747     {
    00748       for (; __pos <= __size - __n; ++__pos)
    00749         if (traits_type::eq(__data[__pos], __s[0])
    00750         && traits_type::compare(__data + __pos + 1,
    00751                     __s + 1, __n - 1) == 0)
    00752           return __pos;
    00753     }
    00754       return npos;
    00755     }
    00756
    00757   template<typename _CharT, typename _Traits, typename _Alloc>
    00758     typename basic_string<_CharT, _Traits, _Alloc>::size_type
    00759     basic_string<_CharT, _Traits, _Alloc>::
    00760     find(_CharT __c, size_type __pos) const
    00761     {
    00762       size_type __ret = npos;
    00763       const size_type __size = this->size();
    00764       if (__pos < __size)
    00765     {
    00766       const _CharT* __data = _M_data();
    00767       const size_type __n = __size - __pos;
    00768       const _CharT* __p = traits_type::find(__data + __pos, __n, __c);
    00769       if (__p)
    00770         __ret = __p - __data;
    00771     }
    00772       return __ret;
    00773     }
    00774
    00775   template<typename _CharT, typename _Traits, typename _Alloc>
    00776     typename basic_string<_CharT, _Traits, _Alloc>::size_type
    00777     basic_string<_CharT, _Traits, _Alloc>::
    00778     rfind(const _CharT* __s, size_type __pos, size_type __n) const
    00779     {
    00780       __glibcxx_requires_string_len(__s, __n);
    00781       const size_type __size = this->size();
    00782       if (__n <= __size)
    00783     {
    00784       __pos = std::min(size_type(__size - __n), __pos);
    00785       const _CharT* __data = _M_data();
    00786       do
    00787         {
    00788           if (traits_type::compare(__data + __pos, __s, __n) == 0)
    00789         return __pos;
    00790         }
    00791       while (__pos-- > 0);
    00792     }
    00793       return npos;
    00794     }
    00795
    00796   template<typename _CharT, typename _Traits, typename _Alloc>
    00797     typename basic_string<_CharT, _Traits, _Alloc>::size_type
    00798     basic_string<_CharT, _Traits, _Alloc>::
    00799     rfind(_CharT __c, size_type __pos) const
    00800     {
    00801       size_type __size = this->size();
    00802       if (__size)
    00803     {
    00804       if (--__size > __pos)
    00805         __size = __pos;
    00806       for (++__size; __size-- > 0; )
    00807         if (traits_type::eq(_M_data()[__size], __c))
    00808           return __size;
    00809     }
    00810       return npos;
    00811     }
    00812
    00813   template<typename _CharT, typename _Traits, typename _Alloc>
    00814     typename basic_string<_CharT, _Traits, _Alloc>::size_type
    00815     basic_string<_CharT, _Traits, _Alloc>::
    00816     find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
    00817     {
    00818       __glibcxx_requires_string_len(__s, __n);
    00819       for (; __n && __pos < this->size(); ++__pos)
    00820     {
    00821       const _CharT* __p = traits_type::find(__s, __n, _M_data()[__pos]);
    00822       if (__p)
    00823         return __pos;
    00824     }
    00825       return npos;
    00826     }
    00827
    00828   template<typename _CharT, typename _Traits, typename _Alloc>
    00829     typename basic_string<_CharT, _Traits, _Alloc>::size_type
    00830     basic_string<_CharT, _Traits, _Alloc>::
    00831     find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
    00832     {
    00833       __glibcxx_requires_string_len(__s, __n);
    00834       size_type __size = this->size();
    00835       if (__size && __n)
    00836     {
    00837       if (--__size > __pos)
    00838         __size = __pos;
    00839       do
    00840         {
    00841           if (traits_type::find(__s, __n, _M_data()[__size]))
    00842         return __size;
    00843         }
    00844       while (__size-- != 0);
    00845     }
    00846       return npos;
    00847     }
    00848
    00849   template<typename _CharT, typename _Traits, typename _Alloc>
    00850     typename basic_string<_CharT, _Traits, _Alloc>::size_type
    00851     basic_string<_CharT, _Traits, _Alloc>::
    00852     find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const
    00853     {
    00854       __glibcxx_requires_string_len(__s, __n);
    00855       for (; __pos < this->size(); ++__pos)
    00856     if (!traits_type::find(__s, __n, _M_data()[__pos]))
    00857       return __pos;
    00858       return npos;
    00859     }
    00860
    00861   template<typename _CharT, typename _Traits, typename _Alloc>
    00862     typename basic_string<_CharT, _Traits, _Alloc>::size_type
    00863     basic_string<_CharT, _Traits, _Alloc>::
    00864     find_first_not_of(_CharT __c, size_type __pos) const
    00865     {
    00866       for (; __pos < this->size(); ++__pos)
    00867     if (!traits_type::eq(_M_data()[__pos], __c))
    00868       return __pos;
    00869       return npos;
    00870     }
    00871
    00872   template<typename _CharT, typename _Traits, typename _Alloc>
    00873     typename basic_string<_CharT, _Traits, _Alloc>::size_type
    00874     basic_string<_CharT, _Traits, _Alloc>::
    00875     find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const
    00876     {
    00877       __glibcxx_requires_string_len(__s, __n);
    00878       size_type __size = this->size();
    00879       if (__size)
    00880     {
    00881       if (--__size > __pos)
    00882         __size = __pos;
    00883       do
    00884         {
    00885           if (!traits_type::find(__s, __n, _M_data()[__size]))
    00886         return __size;
    00887         }
    00888       while (__size--);
    00889     }
    00890       return npos;
    00891     }
    00892
    00893   template<typename _CharT, typename _Traits, typename _Alloc>
    00894     typename basic_string<_CharT, _Traits, _Alloc>::size_type
    00895     basic_string<_CharT, _Traits, _Alloc>::
    00896     find_last_not_of(_CharT __c, size_type __pos) const
    00897     {
    00898       size_type __size = this->size();
    00899       if (__size)
    00900     {
    00901       if (--__size > __pos)
    00902         __size = __pos;
    00903       do
    00904         {
    00905           if (!traits_type::eq(_M_data()[__size], __c))
    00906         return __size;
    00907         }
    00908       while (__size--);
    00909     }
    00910       return npos;
    00911     }
    00912
    00913   template<typename _CharT, typename _Traits, typename _Alloc>
    00914     int
    00915     basic_string<_CharT, _Traits, _Alloc>::
    00916     compare(size_type __pos, size_type __n, const basic_string& __str) const
    00917     {
    00918       _M_check(__pos, "basic_string::compare");
    00919       __n = _M_limit(__pos, __n);
    00920       const size_type __osize = __str.size();
    00921       const size_type __len = std::min(__n, __osize);
    00922       int __r = traits_type::compare(_M_data() + __pos, __str.data(), __len);
    00923       if (!__r)
    00924     __r = _S_compare(__n, __osize);
    00925       return __r;
    00926     }
    00927
    00928   template<typename _CharT, typename _Traits, typename _Alloc>
    00929     int
    00930     basic_string<_CharT, _Traits, _Alloc>::
    00931     compare(size_type __pos1, size_type __n1, const basic_string& __str,
    00932         size_type __pos2, size_type __n2) const
    00933     {
    00934       _M_check(__pos1, "basic_string::compare");
    00935       __str._M_check(__pos2, "basic_string::compare");
    00936       __n1 = _M_limit(__pos1, __n1);
    00937       __n2 = __str._M_limit(__pos2, __n2);
    00938       const size_type __len = std::min(__n1, __n2);
    00939       int __r = traits_type::compare(_M_data() + __pos1,
    00940                      __str.data() + __pos2, __len);
    00941       if (!__r)
    00942     __r = _S_compare(__n1, __n2);
    00943       return __r;
    00944     }
    00945
    00946   template<typename _CharT, typename _Traits, typename _Alloc>
    00947     int
    00948     basic_string<_CharT, _Traits, _Alloc>::
    00949     compare(const _CharT* __s) const
    00950     {
    00951       __glibcxx_requires_string(__s);
    00952       const size_type __size = this->size();
    00953       const size_type __osize = traits_type::length(__s);
    00954       const size_type __len = std::min(__size, __osize);
    00955       int __r = traits_type::compare(_M_data(), __s, __len);
    00956       if (!__r)
    00957     __r = _S_compare(__size, __osize);
    00958       return __r;
    00959     }
    00960
    00961   template<typename _CharT, typename _Traits, typename _Alloc>
    00962     int
    00963     basic_string <_CharT, _Traits, _Alloc>::
    00964     compare(size_type __pos, size_type __n1, const _CharT* __s) const
    00965     {
    00966       __glibcxx_requires_string(__s);
    00967       _M_check(__pos, "basic_string::compare");
    00968       __n1 = _M_limit(__pos, __n1);
    00969       const size_type __osize = traits_type::length(__s);
    00970       const size_type __len = std::min(__n1, __osize);
    00971       int __r = traits_type::compare(_M_data() + __pos, __s, __len);
    00972       if (!__r)
    00973     __r = _S_compare(__n1, __osize);
    00974       return __r;
    00975     }
    00976
    00977   template<typename _CharT, typename _Traits, typename _Alloc>
    00978     int
    00979     basic_string <_CharT, _Traits, _Alloc>::
    00980     compare(size_type __pos, size_type __n1, const _CharT* __s,
    00981         size_type __n2) const
    00982     {
    00983       __glibcxx_requires_string_len(__s, __n2);
    00984       _M_check(__pos, "basic_string::compare");
    00985       __n1 = _M_limit(__pos, __n1);
    00986       const size_type __len = std::min(__n1, __n2);
    00987       int __r = traits_type::compare(_M_data() + __pos, __s, __len);
    00988       if (!__r)
    00989     __r = _S_compare(__n1, __n2);
    00990       return __r;
    00991     }
    00992
    00993   // 21.3.7.9 basic_string::getline and operators
    00994   template<typename _CharT, typename _Traits, typename _Alloc>
    00995     basic_istream<_CharT, _Traits>&
    00996     operator>>(basic_istream<_CharT, _Traits>& __in,
    00997            basic_string<_CharT, _Traits, _Alloc>& __str)
    00998     {
    00999       typedef basic_istream<_CharT, _Traits>        __istream_type;
    01000       typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
    01001       typedef typename __istream_type::ios_base         __ios_base;
    01002       typedef typename __istream_type::int_type     __int_type;
    01003       typedef typename __string_type::size_type     __size_type;
    01004       typedef ctype<_CharT>             __ctype_type;
    01005       typedef typename __ctype_type::ctype_base         __ctype_base;
    01006
    01007       __size_type __extracted = 0;
    01008       typename __ios_base::iostate __err = __ios_base::goodbit;
    01009       typename __istream_type::sentry __cerb(__in, false);
    01010       if (__cerb)
    01011     {
    01012       __try
    01013         {
    01014           // Avoid reallocation for common case.
    01015           __str.erase();
    01016           _CharT __buf[128];
    01017           __size_type __len = 0;
    01018           const streamsize __w = __in.width();
    01019           const __size_type __n = __w > 0 ? static_cast<__size_type>(__w)
    01020                                       : __str.max_size();
    01021           const __ctype_type& __ct = use_facet<__ctype_type>(__in.getloc());
    01022           const __int_type __eof = _Traits::eof();
    01023           __int_type __c = __in.rdbuf()->sgetc();
    01024
    01025           while (__extracted < __n
    01026              && !_Traits::eq_int_type(__c, __eof)
    01027              && !__ct.is(__ctype_base::space,
    01028                  _Traits::to_char_type(__c)))
    01029         {
    01030           if (__len == sizeof(__buf) / sizeof(_CharT))
    01031             {
    01032               __str.append(__buf, sizeof(__buf) / sizeof(_CharT));
    01033               __len = 0;
    01034             }
    01035           __buf[__len++] = _Traits::to_char_type(__c);
    01036           ++__extracted;
    01037           __c = __in.rdbuf()->snextc();
    01038         }
    01039           __str.append(__buf, __len);
    01040
    01041           if (_Traits::eq_int_type(__c, __eof))
    01042         __err |= __ios_base::eofbit;
    01043           __in.width(0);
    01044         }
    01045       __catch(__cxxabiv1::__forced_unwind&)
    01046         {
    01047           __in._M_setstate(__ios_base::badbit);
    01048           __throw_exception_again;
    01049         }
    01050       __catch(...)
    01051         {
    01052           // _GLIBCXX_RESOLVE_LIB_DEFECTS
    01053           // 91. Description of operator>> and getline() for string<>
    01054           // might cause endless loop
    01055           __in._M_setstate(__ios_base::badbit);
    01056         }
    01057     }
    01058       // 211.  operator>>(istream&, string&) doesn't set failbit
    01059       if (!__extracted)
    01060     __err |= __ios_base::failbit;
    01061       if (__err)
    01062     __in.setstate(__err);
    01063       return __in;
    01064     }
    01065
    01066   template<typename _CharT, typename _Traits, typename _Alloc>
    01067     basic_istream<_CharT, _Traits>&
    01068     getline(basic_istream<_CharT, _Traits>& __in,
    01069         basic_string<_CharT, _Traits, _Alloc>& __str, _CharT __delim)
    01070     {
    01071       typedef basic_istream<_CharT, _Traits>        __istream_type;
    01072       typedef basic_string<_CharT, _Traits, _Alloc> __string_type;
    01073       typedef typename __istream_type::ios_base         __ios_base;
    01074       typedef typename __istream_type::int_type     __int_type;
    01075       typedef typename __string_type::size_type     __size_type;
    01076
    01077       __size_type __extracted = 0;
    01078       const __size_type __n = __str.max_size();
    01079       typename __ios_base::iostate __err = __ios_base::goodbit;
    01080       typename __istream_type::sentry __cerb(__in, true);
    01081       if (__cerb)
    01082     {
    01083       __try
    01084         {
    01085           __str.erase();
    01086           const __int_type __idelim = _Traits::to_int_type(__delim);
    01087           const __int_type __eof = _Traits::eof();
    01088           __int_type __c = __in.rdbuf()->sgetc();
    01089
    01090           while (__extracted < __n
    01091              && !_Traits::eq_int_type(__c, __eof)
    01092              && !_Traits::eq_int_type(__c, __idelim))
    01093         {
    01094           __str += _Traits::to_char_type(__c);
    01095           ++__extracted;
    01096           __c = __in.rdbuf()->snextc();
    01097         }
    01098
    01099           if (_Traits::eq_int_type(__c, __eof))
    01100         __err |= __ios_base::eofbit;
    01101           else if (_Traits::eq_int_type(__c, __idelim))
    01102         {
    01103           ++__extracted;
    01104           __in.rdbuf()->sbumpc();
    01105         }
    01106           else
    01107         __err |= __ios_base::failbit;
    01108         }
    01109       __catch(__cxxabiv1::__forced_unwind&)
    01110         {
    01111           __in._M_setstate(__ios_base::badbit);
    01112           __throw_exception_again;
    01113         }
    01114       __catch(...)
    01115         {
    01116           // _GLIBCXX_RESOLVE_LIB_DEFECTS
    01117           // 91. Description of operator>> and getline() for string<>
    01118           // might cause endless loop
    01119           __in._M_setstate(__ios_base::badbit);
    01120         }
    01121     }
    01122       if (!__extracted)
    01123     __err |= __ios_base::failbit;
    01124       if (__err)
    01125     __in.setstate(__err);
    01126       return __in;
    01127     }
    01128
    01129   // Inhibit implicit instantiations for required instantiations,
    01130   // which are defined via explicit instantiations elsewhere.
    01131   // NB: This syntax is a GNU extension.
    01132 #if _GLIBCXX_EXTERN_TEMPLATE > 0
    01133   extern template class basic_string<char>;
    01134   extern template
    01135     basic_istream<char>&
    01136     operator>>(basic_istream<char>&, string&);
    01137   extern template
    01138     basic_ostream<char>&
    01139     operator<<(basic_ostream<char>&, const string&);
    01140   extern template
    01141     basic_istream<char>&
    01142     getline(basic_istream<char>&, string&, char);
    01143   extern template
    01144     basic_istream<char>&
    01145     getline(basic_istream<char>&, string&);
    01146
    01147 #ifdef _GLIBCXX_USE_WCHAR_T
    01148   extern template class basic_string<wchar_t>;
    01149   extern template
    01150     basic_istream<wchar_t>&
    01151     operator>>(basic_istream<wchar_t>&, wstring&);
    01152   extern template
    01153     basic_ostream<wchar_t>&
    01154     operator<<(basic_ostream<wchar_t>&, const wstring&);
    01155   extern template
    01156     basic_istream<wchar_t>&
    01157     getline(basic_istream<wchar_t>&, wstring&, wchar_t);
    01158   extern template
    01159     basic_istream<wchar_t>&
    01160     getline(basic_istream<wchar_t>&, wstring&);
    01161 #endif
    01162 #endif
    01163
    01164 _GLIBCXX_END_NAMESPACE
    01165
    01166 #endif