libstdc++
sstream
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00001 // String based streams -*- C++ -*-
00002 
00003 // Copyright (C) 1997-2019 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the
00007 // terms of the GNU General Public License as published by the
00008 // Free Software Foundation; either version 3, or (at your option)
00009 // any later version.
00010 
00011 // This library is distributed in the hope that it will be useful,
00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 // GNU General Public License for more details.
00015 
00016 // Under Section 7 of GPL version 3, you are granted additional
00017 // permissions described in the GCC Runtime Library Exception, version
00018 // 3.1, as published by the Free Software Foundation.
00019 
00020 // You should have received a copy of the GNU General Public License and
00021 // a copy of the GCC Runtime Library Exception along with this program;
00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00023 // <http://www.gnu.org/licenses/>.
00024 
00025 /** @file include/sstream
00026  *  This is a Standard C++ Library header.
00027  */
00028 
00029 //
00030 // ISO C++ 14882: 27.7  String-based streams
00031 //
00032 
00033 #ifndef _GLIBCXX_SSTREAM
00034 #define _GLIBCXX_SSTREAM 1
00035 
00036 #pragma GCC system_header
00037 
00038 #include <istream>
00039 #include <ostream>
00040 
00041 namespace std _GLIBCXX_VISIBILITY(default)
00042 {
00043 _GLIBCXX_BEGIN_NAMESPACE_VERSION
00044 _GLIBCXX_BEGIN_NAMESPACE_CXX11
00045 
00046   // [27.7.1] template class basic_stringbuf
00047   /**
00048    *  @brief  The actual work of input and output (for std::string).
00049    *  @ingroup io
00050    *
00051    *  @tparam _CharT  Type of character stream.
00052    *  @tparam _Traits  Traits for character type, defaults to
00053    *                   char_traits<_CharT>.
00054    *  @tparam _Alloc  Allocator type, defaults to allocator<_CharT>.
00055    *
00056    *  This class associates either or both of its input and output sequences
00057    *  with a sequence of characters, which can be initialized from, or made
00058    *  available as, a @c std::basic_string.  (Paraphrased from [27.7.1]/1.)
00059    *
00060    *  For this class, open modes (of type @c ios_base::openmode) have
00061    *  @c in set if the input sequence can be read, and @c out set if the
00062    *  output sequence can be written.
00063   */
00064   template<typename _CharT, typename _Traits, typename _Alloc>
00065     class basic_stringbuf : public basic_streambuf<_CharT, _Traits>
00066     {
00067       struct __xfer_bufptrs;
00068     public:
00069       // Types:
00070       typedef _CharT                                    char_type;
00071       typedef _Traits                                   traits_type;
00072       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00073       // 251. basic_stringbuf missing allocator_type
00074       typedef _Alloc                                    allocator_type;
00075       typedef typename traits_type::int_type            int_type;
00076       typedef typename traits_type::pos_type            pos_type;
00077       typedef typename traits_type::off_type            off_type;
00078 
00079       typedef basic_streambuf<char_type, traits_type>   __streambuf_type;
00080       typedef basic_string<char_type, _Traits, _Alloc>  __string_type;
00081       typedef typename __string_type::size_type         __size_type;
00082 
00083     protected:
00084       /// Place to stash in || out || in | out settings for current stringbuf.
00085       ios_base::openmode        _M_mode;
00086 
00087       // Data Members:
00088       __string_type             _M_string;
00089 
00090     public:
00091       // Constructors:
00092 
00093       /**
00094        *  @brief  Starts with an empty string buffer.
00095        *
00096        *  The default constructor initializes the parent class using its
00097        *  own default ctor.
00098       */
00099       basic_stringbuf()
00100       : __streambuf_type(), _M_mode(ios_base::in | ios_base::out), _M_string()
00101       { }
00102 
00103       /**
00104        *  @brief  Starts with an empty string buffer.
00105        *  @param  __mode  Whether the buffer can read, or write, or both.
00106        *
00107        *  The default constructor initializes the parent class using its
00108        *  own default ctor.
00109       */
00110       explicit
00111       basic_stringbuf(ios_base::openmode __mode)
00112       : __streambuf_type(), _M_mode(__mode), _M_string()
00113       { }
00114 
00115       /**
00116        *  @brief  Starts with an existing string buffer.
00117        *  @param  __str  A string to copy as a starting buffer.
00118        *  @param  __mode  Whether the buffer can read, or write, or both.
00119        *
00120        *  This constructor initializes the parent class using its
00121        *  own default ctor.
00122       */
00123       explicit
00124       basic_stringbuf(const __string_type& __str,
00125                       ios_base::openmode __mode = ios_base::in | ios_base::out)
00126       : __streambuf_type(), _M_mode(),
00127         _M_string(__str.data(), __str.size(), __str.get_allocator())
00128       { _M_stringbuf_init(__mode); }
00129 
00130 #if __cplusplus >= 201103L
00131       basic_stringbuf(const basic_stringbuf&) = delete;
00132 
00133       basic_stringbuf(basic_stringbuf&& __rhs)
00134       : basic_stringbuf(std::move(__rhs), __xfer_bufptrs(__rhs, this))
00135       { __rhs._M_sync(const_cast<char_type*>(__rhs._M_string.data()), 0, 0); }
00136 
00137       // 27.8.2.2 Assign and swap:
00138 
00139       basic_stringbuf&
00140       operator=(const basic_stringbuf&) = delete;
00141 
00142       basic_stringbuf&
00143       operator=(basic_stringbuf&& __rhs)
00144       {
00145         __xfer_bufptrs __st{__rhs, this};
00146         const __streambuf_type& __base = __rhs;
00147         __streambuf_type::operator=(__base);
00148         this->pubimbue(__rhs.getloc());
00149         _M_mode = __rhs._M_mode;
00150         _M_string = std::move(__rhs._M_string);
00151         __rhs._M_sync(const_cast<char_type*>(__rhs._M_string.data()), 0, 0);
00152         return *this;
00153       }
00154 
00155       void
00156       swap(basic_stringbuf& __rhs)
00157       {
00158         __xfer_bufptrs __l_st{*this, std::__addressof(__rhs)};
00159         __xfer_bufptrs __r_st{__rhs, this};
00160         __streambuf_type& __base = __rhs;
00161         __streambuf_type::swap(__base);
00162         __rhs.pubimbue(this->pubimbue(__rhs.getloc()));
00163         std::swap(_M_mode, __rhs._M_mode);
00164         std::swap(_M_string, __rhs._M_string);
00165       }
00166 #endif
00167 
00168       // Get and set:
00169       /**
00170        *  @brief  Copying out the string buffer.
00171        *  @return  A copy of one of the underlying sequences.
00172        *
00173        *  <em>If the buffer is only created in input mode, the underlying
00174        *  character sequence is equal to the input sequence; otherwise, it
00175        *  is equal to the output sequence.</em> [27.7.1.2]/1
00176       */
00177       __string_type
00178       str() const
00179       {
00180         __string_type __ret(_M_string.get_allocator());
00181         if (this->pptr())
00182           {
00183             // The current egptr() may not be the actual string end.
00184             if (this->pptr() > this->egptr())
00185               __ret.assign(this->pbase(), this->pptr());
00186             else
00187               __ret.assign(this->pbase(), this->egptr());
00188           }
00189         else
00190           __ret = _M_string;
00191         return __ret;
00192       }
00193 
00194       /**
00195        *  @brief  Setting a new buffer.
00196        *  @param  __s  The string to use as a new sequence.
00197        *
00198        *  Deallocates any previous stored sequence, then copies @a s to
00199        *  use as a new one.
00200       */
00201       void
00202       str(const __string_type& __s)
00203       {
00204         // Cannot use _M_string = __s, since v3 strings are COW
00205         // (not always true now but assign() always works).
00206         _M_string.assign(__s.data(), __s.size());
00207         _M_stringbuf_init(_M_mode);
00208       }
00209 
00210     protected:
00211       // Common initialization code goes here.
00212       void
00213       _M_stringbuf_init(ios_base::openmode __mode)
00214       {
00215         _M_mode = __mode;
00216         __size_type __len = 0;
00217         if (_M_mode & (ios_base::ate | ios_base::app))
00218           __len = _M_string.size();
00219         _M_sync(const_cast<char_type*>(_M_string.data()), 0, __len);
00220       }
00221 
00222       virtual streamsize
00223       showmanyc()
00224       {
00225         streamsize __ret = -1;
00226         if (_M_mode & ios_base::in)
00227           {
00228             _M_update_egptr();
00229             __ret = this->egptr() - this->gptr();
00230           }
00231         return __ret;
00232       }
00233 
00234       virtual int_type
00235       underflow();
00236 
00237       virtual int_type
00238       pbackfail(int_type __c = traits_type::eof());
00239 
00240       virtual int_type
00241       overflow(int_type __c = traits_type::eof());
00242 
00243       /**
00244        *  @brief  Manipulates the buffer.
00245        *  @param  __s  Pointer to a buffer area.
00246        *  @param  __n  Size of @a __s.
00247        *  @return  @c this
00248        *
00249        *  If no buffer has already been created, and both @a __s and @a __n are
00250        *  non-zero, then @c __s is used as a buffer; see
00251        *  https://gcc.gnu.org/onlinedocs/libstdc++/manual/streambufs.html#io.streambuf.buffering
00252        *  for more.
00253       */
00254       virtual __streambuf_type*
00255       setbuf(char_type* __s, streamsize __n)
00256       {
00257         if (__s && __n >= 0)
00258           {
00259             // This is implementation-defined behavior, and assumes
00260             // that an external char_type array of length __n exists
00261             // and has been pre-allocated. If this is not the case,
00262             // things will quickly blow up.
00263 
00264             // Step 1: Destroy the current internal array.
00265             _M_string.clear();
00266 
00267             // Step 2: Use the external array.
00268             _M_sync(__s, __n, 0);
00269           }
00270         return this;
00271       }
00272 
00273       virtual pos_type
00274       seekoff(off_type __off, ios_base::seekdir __way,
00275               ios_base::openmode __mode = ios_base::in | ios_base::out);
00276 
00277       virtual pos_type
00278       seekpos(pos_type __sp,
00279               ios_base::openmode __mode = ios_base::in | ios_base::out);
00280 
00281       // Internal function for correctly updating the internal buffer
00282       // for a particular _M_string, due to initialization or re-sizing
00283       // of an existing _M_string.
00284       void
00285       _M_sync(char_type* __base, __size_type __i, __size_type __o);
00286 
00287       // Internal function for correctly updating egptr() to the actual
00288       // string end.
00289       void
00290       _M_update_egptr()
00291       {
00292         const bool __testin = _M_mode & ios_base::in;
00293         if (this->pptr() && this->pptr() > this->egptr())
00294           {
00295             if (__testin)
00296               this->setg(this->eback(), this->gptr(), this->pptr());
00297             else
00298               this->setg(this->pptr(), this->pptr(), this->pptr());
00299           }
00300       }
00301 
00302       // Works around the issue with pbump, part of the protected
00303       // interface of basic_streambuf, taking just an int.
00304       void
00305       _M_pbump(char_type* __pbeg, char_type* __pend, off_type __off);
00306 
00307     private:
00308 #if __cplusplus >= 201103L
00309 #if _GLIBCXX_USE_CXX11_ABI
00310       // This type captures the state of the gptr / pptr pointers as offsets
00311       // so they can be restored in another object after moving the string.
00312       struct __xfer_bufptrs
00313       {
00314         __xfer_bufptrs(const basic_stringbuf& __from, basic_stringbuf* __to)
00315         : _M_to{__to}, _M_goff{-1, -1, -1}, _M_poff{-1, -1, -1}
00316         {
00317           const _CharT* const __str = __from._M_string.data();
00318           const _CharT* __end = nullptr;
00319           if (__from.eback())
00320             {
00321               _M_goff[0] = __from.eback() - __str;
00322               _M_goff[1] = __from.gptr() - __str;
00323               _M_goff[2] = __from.egptr() - __str;
00324               __end = __from.egptr();
00325             }
00326           if (__from.pbase())
00327             {
00328               _M_poff[0] = __from.pbase() - __str;
00329               _M_poff[1] = __from.pptr() - __from.pbase();
00330               _M_poff[2] = __from.epptr() - __str;
00331               if (__from.pptr() > __end)
00332                 __end = __from.pptr();
00333             }
00334 
00335           // Set _M_string length to the greater of the get and put areas.
00336           if (__end)
00337             {
00338               // The const_cast avoids changing this constructor's signature,
00339               // because it is exported from the dynamic library.
00340               auto& __mut_from = const_cast<basic_stringbuf&>(__from);
00341               __mut_from._M_string._M_length(__end - __str);
00342             }
00343         }
00344 
00345         ~__xfer_bufptrs()
00346         {
00347           char_type* __str = const_cast<char_type*>(_M_to->_M_string.data());
00348           if (_M_goff[0] != -1)
00349             _M_to->setg(__str+_M_goff[0], __str+_M_goff[1], __str+_M_goff[2]);
00350           if (_M_poff[0] != -1)
00351             _M_to->_M_pbump(__str+_M_poff[0], __str+_M_poff[2], _M_poff[1]);
00352         }
00353 
00354         basic_stringbuf* _M_to;
00355         off_type _M_goff[3];
00356         off_type _M_poff[3];
00357       };
00358 #else
00359       // This type does nothing when using Copy-On-Write strings.
00360       struct __xfer_bufptrs
00361       {
00362         __xfer_bufptrs(const basic_stringbuf&, basic_stringbuf*) { }
00363       };
00364 #endif
00365 
00366       // The move constructor initializes an __xfer_bufptrs temporary then
00367       // delegates to this constructor to performs moves during its lifetime.
00368       basic_stringbuf(basic_stringbuf&& __rhs, __xfer_bufptrs&&)
00369       : __streambuf_type(static_cast<const __streambuf_type&>(__rhs)),
00370       _M_mode(__rhs._M_mode), _M_string(std::move(__rhs._M_string))
00371       { }
00372 #endif
00373     };
00374 
00375 
00376   // [27.7.2] Template class basic_istringstream
00377   /**
00378    *  @brief  Controlling input for std::string.
00379    *  @ingroup io
00380    *
00381    *  @tparam _CharT  Type of character stream.
00382    *  @tparam _Traits  Traits for character type, defaults to
00383    *                   char_traits<_CharT>.
00384    *  @tparam _Alloc  Allocator type, defaults to allocator<_CharT>.
00385    *
00386    *  This class supports reading from objects of type std::basic_string,
00387    *  using the inherited functions from std::basic_istream.  To control
00388    *  the associated sequence, an instance of std::basic_stringbuf is used,
00389    *  which this page refers to as @c sb.
00390   */
00391   template<typename _CharT, typename _Traits, typename _Alloc>
00392     class basic_istringstream : public basic_istream<_CharT, _Traits>
00393     {
00394     public:
00395       // Types:
00396       typedef _CharT                                    char_type;
00397       typedef _Traits                                   traits_type;
00398       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00399       // 251. basic_stringbuf missing allocator_type
00400       typedef _Alloc                                    allocator_type;
00401       typedef typename traits_type::int_type            int_type;
00402       typedef typename traits_type::pos_type            pos_type;
00403       typedef typename traits_type::off_type            off_type;
00404 
00405       // Non-standard types:
00406       typedef basic_string<_CharT, _Traits, _Alloc>     __string_type;
00407       typedef basic_stringbuf<_CharT, _Traits, _Alloc>  __stringbuf_type;
00408       typedef basic_istream<char_type, traits_type>     __istream_type;
00409 
00410     private:
00411       __stringbuf_type  _M_stringbuf;
00412 
00413     public:
00414       // Constructors:
00415 
00416       /**
00417        *  @brief  Default constructor starts with an empty string buffer.
00418        *
00419        *  Initializes @c sb using @c in, and passes @c &sb to the base
00420        *  class initializer.  Does not allocate any buffer.
00421        *
00422        *  That's a lie.  We initialize the base class with NULL, because the
00423        *  string class does its own memory management.
00424       */
00425       basic_istringstream()
00426       : __istream_type(), _M_stringbuf(ios_base::in)
00427       { this->init(&_M_stringbuf); }
00428 
00429       /**
00430        *  @brief  Starts with an empty string buffer.
00431        *  @param  __mode  Whether the buffer can read, or write, or both.
00432        *
00433        *  @c ios_base::in is automatically included in @a __mode.
00434        *
00435        *  Initializes @c sb using @c __mode|in, and passes @c &sb to the base
00436        *  class initializer.  Does not allocate any buffer.
00437        *
00438        *  That's a lie.  We initialize the base class with NULL, because the
00439        *  string class does its own memory management.
00440       */
00441       explicit
00442       basic_istringstream(ios_base::openmode __mode)
00443       : __istream_type(), _M_stringbuf(__mode | ios_base::in)
00444       { this->init(&_M_stringbuf); }
00445 
00446       /**
00447        *  @brief  Starts with an existing string buffer.
00448        *  @param  __str  A string to copy as a starting buffer.
00449        *  @param  __mode  Whether the buffer can read, or write, or both.
00450        *
00451        *  @c ios_base::in is automatically included in @a mode.
00452        *
00453        *  Initializes @c sb using @a str and @c mode|in, and passes @c &sb
00454        *  to the base class initializer.
00455        *
00456        *  That's a lie.  We initialize the base class with NULL, because the
00457        *  string class does its own memory management.
00458       */
00459       explicit
00460       basic_istringstream(const __string_type& __str,
00461                           ios_base::openmode __mode = ios_base::in)
00462       : __istream_type(), _M_stringbuf(__str, __mode | ios_base::in)
00463       { this->init(&_M_stringbuf); }
00464 
00465       /**
00466        *  @brief  The destructor does nothing.
00467        *
00468        *  The buffer is deallocated by the stringbuf object, not the
00469        *  formatting stream.
00470       */
00471       ~basic_istringstream()
00472       { }
00473 
00474 #if __cplusplus >= 201103L
00475       basic_istringstream(const basic_istringstream&) = delete;
00476 
00477       basic_istringstream(basic_istringstream&& __rhs)
00478       : __istream_type(std::move(__rhs)),
00479       _M_stringbuf(std::move(__rhs._M_stringbuf))
00480       { __istream_type::set_rdbuf(&_M_stringbuf); }
00481 
00482       // 27.8.3.2 Assign and swap:
00483 
00484       basic_istringstream&
00485       operator=(const basic_istringstream&) = delete;
00486 
00487       basic_istringstream&
00488       operator=(basic_istringstream&& __rhs)
00489       {
00490         __istream_type::operator=(std::move(__rhs));
00491         _M_stringbuf = std::move(__rhs._M_stringbuf);
00492         return *this;
00493       }
00494 
00495       void
00496       swap(basic_istringstream& __rhs)
00497       {
00498         __istream_type::swap(__rhs);
00499         _M_stringbuf.swap(__rhs._M_stringbuf);
00500       }
00501 #endif
00502 
00503       // Members:
00504       /**
00505        *  @brief  Accessing the underlying buffer.
00506        *  @return  The current basic_stringbuf buffer.
00507        *
00508        *  This hides both signatures of std::basic_ios::rdbuf().
00509       */
00510       __stringbuf_type*
00511       rdbuf() const
00512       { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
00513 
00514       /**
00515        *  @brief  Copying out the string buffer.
00516        *  @return  @c rdbuf()->str()
00517       */
00518       __string_type
00519       str() const
00520       { return _M_stringbuf.str(); }
00521 
00522       /**
00523        *  @brief  Setting a new buffer.
00524        *  @param  __s  The string to use as a new sequence.
00525        *
00526        *  Calls @c rdbuf()->str(s).
00527       */
00528       void
00529       str(const __string_type& __s)
00530       { _M_stringbuf.str(__s); }
00531     };
00532 
00533 
00534   // [27.7.3] Template class basic_ostringstream
00535   /**
00536    *  @brief  Controlling output for std::string.
00537    *  @ingroup io
00538    *
00539    *  @tparam _CharT  Type of character stream.
00540    *  @tparam _Traits  Traits for character type, defaults to
00541    *                   char_traits<_CharT>.
00542    *  @tparam _Alloc  Allocator type, defaults to allocator<_CharT>.
00543    *
00544    *  This class supports writing to objects of type std::basic_string,
00545    *  using the inherited functions from std::basic_ostream.  To control
00546    *  the associated sequence, an instance of std::basic_stringbuf is used,
00547    *  which this page refers to as @c sb.
00548   */
00549   template <typename _CharT, typename _Traits, typename _Alloc>
00550     class basic_ostringstream : public basic_ostream<_CharT, _Traits>
00551     {
00552     public:
00553       // Types:
00554       typedef _CharT                                    char_type;
00555       typedef _Traits                                   traits_type;
00556       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00557       // 251. basic_stringbuf missing allocator_type
00558       typedef _Alloc                                    allocator_type;
00559       typedef typename traits_type::int_type            int_type;
00560       typedef typename traits_type::pos_type            pos_type;
00561       typedef typename traits_type::off_type            off_type;
00562 
00563       // Non-standard types:
00564       typedef basic_string<_CharT, _Traits, _Alloc>     __string_type;
00565       typedef basic_stringbuf<_CharT, _Traits, _Alloc>  __stringbuf_type;
00566       typedef basic_ostream<char_type, traits_type>     __ostream_type;
00567 
00568     private:
00569       __stringbuf_type  _M_stringbuf;
00570 
00571     public:
00572       // Constructors/destructor:
00573 
00574       /**
00575        *  @brief  Default constructor starts with an empty string buffer.
00576        *
00577        *  Initializes @c sb using @c mode|out, and passes @c &sb to the base
00578        *  class initializer.  Does not allocate any buffer.
00579        *
00580        *  That's a lie.  We initialize the base class with NULL, because the
00581        *  string class does its own memory management.
00582       */
00583       basic_ostringstream()
00584       : __ostream_type(), _M_stringbuf(ios_base::out)
00585       { this->init(&_M_stringbuf); }
00586 
00587       /**
00588        *  @brief  Starts with an empty string buffer.
00589        *  @param  __mode  Whether the buffer can read, or write, or both.
00590        *
00591        *  @c ios_base::out is automatically included in @a mode.
00592        *
00593        *  Initializes @c sb using @c mode|out, and passes @c &sb to the base
00594        *  class initializer.  Does not allocate any buffer.
00595        *
00596        *  That's a lie.  We initialize the base class with NULL, because the
00597        *  string class does its own memory management.
00598       */
00599       explicit
00600       basic_ostringstream(ios_base::openmode __mode)
00601       : __ostream_type(), _M_stringbuf(__mode | ios_base::out)
00602       { this->init(&_M_stringbuf); }
00603 
00604       /**
00605        *  @brief  Starts with an existing string buffer.
00606        *  @param  __str  A string to copy as a starting buffer.
00607        *  @param  __mode  Whether the buffer can read, or write, or both.
00608        *
00609        *  @c ios_base::out is automatically included in @a mode.
00610        *
00611        *  Initializes @c sb using @a str and @c mode|out, and passes @c &sb
00612        *  to the base class initializer.
00613        *
00614        *  That's a lie.  We initialize the base class with NULL, because the
00615        *  string class does its own memory management.
00616       */
00617       explicit
00618       basic_ostringstream(const __string_type& __str,
00619                           ios_base::openmode __mode = ios_base::out)
00620       : __ostream_type(), _M_stringbuf(__str, __mode | ios_base::out)
00621       { this->init(&_M_stringbuf); }
00622 
00623       /**
00624        *  @brief  The destructor does nothing.
00625        *
00626        *  The buffer is deallocated by the stringbuf object, not the
00627        *  formatting stream.
00628       */
00629       ~basic_ostringstream()
00630       { }
00631 
00632 #if __cplusplus >= 201103L
00633       basic_ostringstream(const basic_ostringstream&) = delete;
00634 
00635       basic_ostringstream(basic_ostringstream&& __rhs)
00636       : __ostream_type(std::move(__rhs)),
00637       _M_stringbuf(std::move(__rhs._M_stringbuf))
00638       { __ostream_type::set_rdbuf(&_M_stringbuf); }
00639 
00640       // 27.8.3.2 Assign and swap:
00641 
00642       basic_ostringstream&
00643       operator=(const basic_ostringstream&) = delete;
00644 
00645       basic_ostringstream&
00646       operator=(basic_ostringstream&& __rhs)
00647       {
00648         __ostream_type::operator=(std::move(__rhs));
00649         _M_stringbuf = std::move(__rhs._M_stringbuf);
00650         return *this;
00651       }
00652 
00653       void
00654       swap(basic_ostringstream& __rhs)
00655       {
00656         __ostream_type::swap(__rhs);
00657         _M_stringbuf.swap(__rhs._M_stringbuf);
00658       }
00659 #endif
00660 
00661       // Members:
00662       /**
00663        *  @brief  Accessing the underlying buffer.
00664        *  @return  The current basic_stringbuf buffer.
00665        *
00666        *  This hides both signatures of std::basic_ios::rdbuf().
00667       */
00668       __stringbuf_type*
00669       rdbuf() const
00670       { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
00671 
00672       /**
00673        *  @brief  Copying out the string buffer.
00674        *  @return  @c rdbuf()->str()
00675       */
00676       __string_type
00677       str() const
00678       { return _M_stringbuf.str(); }
00679 
00680       /**
00681        *  @brief  Setting a new buffer.
00682        *  @param  __s  The string to use as a new sequence.
00683        *
00684        *  Calls @c rdbuf()->str(s).
00685       */
00686       void
00687       str(const __string_type& __s)
00688       { _M_stringbuf.str(__s); }
00689     };
00690 
00691 
00692   // [27.7.4] Template class basic_stringstream
00693   /**
00694    *  @brief  Controlling input and output for std::string.
00695    *  @ingroup io
00696    *
00697    *  @tparam _CharT  Type of character stream.
00698    *  @tparam _Traits  Traits for character type, defaults to
00699    *                   char_traits<_CharT>.
00700    *  @tparam _Alloc  Allocator type, defaults to allocator<_CharT>.
00701    *
00702    *  This class supports reading from and writing to objects of type
00703    *  std::basic_string, using the inherited functions from
00704    *  std::basic_iostream.  To control the associated sequence, an instance
00705    *  of std::basic_stringbuf is used, which this page refers to as @c sb.
00706   */
00707   template <typename _CharT, typename _Traits, typename _Alloc>
00708     class basic_stringstream : public basic_iostream<_CharT, _Traits>
00709     {
00710     public:
00711       // Types:
00712       typedef _CharT                                    char_type;
00713       typedef _Traits                                   traits_type;
00714       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00715       // 251. basic_stringbuf missing allocator_type
00716       typedef _Alloc                                    allocator_type;
00717       typedef typename traits_type::int_type            int_type;
00718       typedef typename traits_type::pos_type            pos_type;
00719       typedef typename traits_type::off_type            off_type;
00720 
00721       // Non-standard Types:
00722       typedef basic_string<_CharT, _Traits, _Alloc>     __string_type;
00723       typedef basic_stringbuf<_CharT, _Traits, _Alloc>  __stringbuf_type;
00724       typedef basic_iostream<char_type, traits_type>    __iostream_type;
00725 
00726     private:
00727       __stringbuf_type  _M_stringbuf;
00728 
00729     public:
00730       // Constructors/destructors
00731 
00732       /**
00733        *  @brief  Default constructor starts with an empty string buffer.
00734        *
00735        *  Initializes @c sb using the mode @c in|out, and passes @c &sb
00736        *  to the base class initializer.  Does not allocate any buffer.
00737        *
00738        *  That's a lie.  We initialize the base class with NULL, because the
00739        *  string class does its own memory management.
00740       */
00741       basic_stringstream()
00742       : __iostream_type(), _M_stringbuf(ios_base::out | ios_base::in)
00743       { this->init(&_M_stringbuf); }
00744 
00745       /**
00746        *  @brief  Starts with an empty string buffer.
00747        *  @param  __m  Whether the buffer can read, or write, or both.
00748        *
00749        *  Initializes @c sb using the mode from @c __m, and passes @c &sb
00750        *  to the base class initializer.  Does not allocate any buffer.
00751        *
00752        *  That's a lie.  We initialize the base class with NULL, because the
00753        *  string class does its own memory management.
00754       */
00755       explicit
00756       basic_stringstream(ios_base::openmode __m)
00757       : __iostream_type(), _M_stringbuf(__m)
00758       { this->init(&_M_stringbuf); }
00759 
00760       /**
00761        *  @brief  Starts with an existing string buffer.
00762        *  @param  __str  A string to copy as a starting buffer.
00763        *  @param  __m  Whether the buffer can read, or write, or both.
00764        *
00765        *  Initializes @c sb using @a __str and @c __m, and passes @c &sb
00766        *  to the base class initializer.
00767        *
00768        *  That's a lie.  We initialize the base class with NULL, because the
00769        *  string class does its own memory management.
00770       */
00771       explicit
00772       basic_stringstream(const __string_type& __str,
00773                          ios_base::openmode __m = ios_base::out | ios_base::in)
00774       : __iostream_type(), _M_stringbuf(__str, __m)
00775       { this->init(&_M_stringbuf); }
00776 
00777       /**
00778        *  @brief  The destructor does nothing.
00779        *
00780        *  The buffer is deallocated by the stringbuf object, not the
00781        *  formatting stream.
00782       */
00783       ~basic_stringstream()
00784       { }
00785 
00786 #if __cplusplus >= 201103L
00787       basic_stringstream(const basic_stringstream&) = delete;
00788 
00789       basic_stringstream(basic_stringstream&& __rhs)
00790       : __iostream_type(std::move(__rhs)),
00791       _M_stringbuf(std::move(__rhs._M_stringbuf))
00792       { __iostream_type::set_rdbuf(&_M_stringbuf); }
00793 
00794       // 27.8.3.2 Assign and swap:
00795 
00796       basic_stringstream&
00797       operator=(const basic_stringstream&) = delete;
00798 
00799       basic_stringstream&
00800       operator=(basic_stringstream&& __rhs)
00801       {
00802         __iostream_type::operator=(std::move(__rhs));
00803         _M_stringbuf = std::move(__rhs._M_stringbuf);
00804         return *this;
00805       }
00806 
00807       void
00808       swap(basic_stringstream& __rhs)
00809       {
00810         __iostream_type::swap(__rhs);
00811         _M_stringbuf.swap(__rhs._M_stringbuf);
00812       }
00813 #endif
00814 
00815       // Members:
00816       /**
00817        *  @brief  Accessing the underlying buffer.
00818        *  @return  The current basic_stringbuf buffer.
00819        *
00820        *  This hides both signatures of std::basic_ios::rdbuf().
00821       */
00822       __stringbuf_type*
00823       rdbuf() const
00824       { return const_cast<__stringbuf_type*>(&_M_stringbuf); }
00825 
00826       /**
00827        *  @brief  Copying out the string buffer.
00828        *  @return  @c rdbuf()->str()
00829       */
00830       __string_type
00831       str() const
00832       { return _M_stringbuf.str(); }
00833 
00834       /**
00835        *  @brief  Setting a new buffer.
00836        *  @param  __s  The string to use as a new sequence.
00837        *
00838        *  Calls @c rdbuf()->str(s).
00839       */
00840       void
00841       str(const __string_type& __s)
00842       { _M_stringbuf.str(__s); }
00843     };
00844 
00845 #if __cplusplus >= 201103L
00846   /// Swap specialization for stringbufs.
00847   template <class _CharT, class _Traits, class _Allocator>
00848     inline void
00849     swap(basic_stringbuf<_CharT, _Traits, _Allocator>& __x,
00850          basic_stringbuf<_CharT, _Traits, _Allocator>& __y)
00851     { __x.swap(__y); }
00852 
00853   /// Swap specialization for istringstreams.
00854   template <class _CharT, class _Traits, class _Allocator>
00855     inline void
00856     swap(basic_istringstream<_CharT, _Traits, _Allocator>& __x,
00857          basic_istringstream<_CharT, _Traits, _Allocator>& __y)
00858     { __x.swap(__y); }
00859 
00860   /// Swap specialization for ostringstreams.
00861   template <class _CharT, class _Traits, class _Allocator>
00862     inline void
00863     swap(basic_ostringstream<_CharT, _Traits, _Allocator>& __x,
00864          basic_ostringstream<_CharT, _Traits, _Allocator>& __y)
00865     { __x.swap(__y); }
00866 
00867   /// Swap specialization for stringstreams.
00868   template <class _CharT, class _Traits, class _Allocator>
00869     inline void
00870     swap(basic_stringstream<_CharT, _Traits, _Allocator>& __x,
00871          basic_stringstream<_CharT, _Traits, _Allocator>& __y)
00872     { __x.swap(__y); }
00873 #endif
00874 
00875 _GLIBCXX_END_NAMESPACE_CXX11
00876 _GLIBCXX_END_NAMESPACE_VERSION
00877 } // namespace
00878 
00879 #include <bits/sstream.tcc>
00880 
00881 #endif /* _GLIBCXX_SSTREAM */