// String based streams -*- C++ -*-

// Copyright (C) 1997, 1998, 1999, 2002, 2003, 2004

// Free Software Foundation, Inc.

//

// This file is part of the GNU ISO C++ Library.  This library is free

// software; you can redistribute it and/or modify it under the

// terms of the GNU General Public License as published by the

// Free Software Foundation; either version 2, or (at your option)

// any later version.

// This library is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License along

// with this library; see the file COPYING.  If not, write to the Free

// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,

// USA.

// As a special exception, you may use this file as part of a free software

// library without restriction.  Specifically, if other files instantiate

// templates or use macros or inline functions from this file, or you compile

// this file and link it with other files to produce an executable, this

// file does not by itself cause the resulting executable to be covered by

// the GNU General Public License.  This exception does not however

// invalidate any other reasons why the executable file might be covered by

// the GNU General Public License.

//

// ISO C++ 14882: 27.7  String-based streams

//

/** @file sstream

 *  This is a Standard C++ Library header.  You should @c #include this header

 *  in your programs, rather than any of the "st[dl]_*.h" implementation files.

 */

#ifndef _GLIBCXX_SSTREAM

#define _GLIBCXX_SSTREAM 1

#pragma GCC system_header

#include <istream>

#include <ostream>

namespace std

{

  // [27.7.1] template class basic_stringbuf

  /**

   *  @brief  The actual work of input and output (for std::string).

   *

   *  This class associates either or both of its input and output sequences

   *  with a sequence of characters, which can be initialized from, or made

   *  available as, a @c std::basic_string.  (Paraphrased from [27.7.1]/1.)

   *

   *  For this class, open modes (of type @c ios_base::openmode) have

   *  @c in set if the input sequence can be read, and @c out set if the

   *  output sequence can be written.

  */

  template<typename _CharT, typename _Traits, typename _Alloc>

    class basic_stringbuf : public basic_streambuf<_CharT, _Traits>

    {

    public:

      // Types:

      typedef _CharT 					char_type;

      typedef _Traits 					traits_type;

      // _GLIBCXX_RESOLVE_LIB_DEFECTS

      // 251. basic_stringbuf missing allocator_type

      typedef _Alloc				       	allocator_type;

      typedef typename traits_type::int_type 		int_type;

      typedef typename traits_type::pos_type 		pos_type;

      typedef typename traits_type::off_type 		off_type;

      //@{

      /**

       *  @if maint

       *  @doctodo

       *  @endif

      */

      typedef basic_streambuf<char_type, traits_type>  	__streambuf_type;

      typedef basic_string<char_type, _Traits, _Alloc> 	__string_type;

      typedef typename __string_type::size_type		__size_type;

      //@}

    protected:

      /**

       *  @if maint

       *  Place to stash in || out || in | out settings for current stringbuf.

       *  @endif

      */

      ios_base::openmode 	_M_mode;

      // Data Members:

      /**

       *  @if maint

       *  @doctodo

       *  @endif

      */

      __string_type 		_M_string;

    public:

      // Constructors:

      /**

       *  @brief  Starts with an empty string buffer.

       *  @param  mode  Whether the buffer can read, or write, or both.

       *

       *  The default constructor initializes the parent class using its

       *  own default ctor.

      */

      explicit

      basic_stringbuf(ios_base::openmode __mode = ios_base::in | ios_base::out)

      : __streambuf_type(), _M_mode(__mode), _M_string()

      { }

      /**

       *  @brief  Starts with an existing string buffer.

       *  @param  str  A string to copy as a starting buffer.

       *  @param  mode  Whether the buffer can read, or write, or both.

       *

       *  This constructor initializes the parent class using its

       *  own default ctor.

      */

      explicit

      basic_stringbuf(const __string_type& __str,

		      ios_base::openmode __mode = ios_base::in | ios_base::out)

      : __streambuf_type(), _M_mode(), _M_string(__str.data(), __str.size())

      { _M_stringbuf_init(__mode); }

      // Get and set:

      /**

       *  @brief  Copying out the string buffer.

       *  @return  A copy of one of the underlying sequences.

       *

       *  "If the buffer is only created in input mode, the underlying

       *  character sequence is equal to the input sequence; otherwise, it

       *  is equal to the output sequence." [27.7.1.2]/1

      */

      __string_type

      str() const

      {

	if (this->pptr())

	  {

	    // The current egptr() may not be the actual string end.

	    if (this->pptr() > this->egptr())

	      return __string_type(this->pbase(), this->pptr());

	    else

 	      return __string_type(this->pbase(), this->egptr());

	  }

	else

	  return _M_string;

      }

      /**

       *  @brief  Setting a new buffer.

       *  @param  s  The string to use as a new sequence.

       *

       *  Deallocates any previous stored sequence, then copies @a s to

       *  use as a new one.

      */

      void

      str(const __string_type& __s)

      {

	// Cannot use _M_string = __s, since v3 strings are COW.

	_M_string.assign(__s.data(), __s.size());

	_M_stringbuf_init(this->_M_mode);

      }

    protected:

      // Common initialization code goes here.

      /**

       *  @if maint

       *  @doctodo

       *  @endif

      */

      void

      _M_stringbuf_init(ios_base::openmode __mode)

      {

	this->_M_mode = __mode;

	__size_type __len = 0;

	if (this->_M_mode & (ios_base::ate | ios_base::app))

	  __len = _M_string.size();

	_M_sync(const_cast<char_type*>(_M_string.data()), 0, __len);

      }

      // [documentation is inherited]

      virtual int_type

      underflow();

      // [documentation is inherited]

      virtual int_type

      pbackfail(int_type __c = traits_type::eof());

      // [documentation is inherited]

      virtual int_type

      overflow(int_type __c = traits_type::eof());

      /**

       *  @brief  Manipulates the buffer.

       *  @param  s  Pointer to a buffer area.

       *  @param  n  Size of @a s.

       *  @return  @c this

       *

       *  If no buffer has already been created, and both @a s and @a n are

       *  non-zero, then @c s is used as a buffer; see

       *  http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#2

       *  for more.

      */

      virtual __streambuf_type*

      setbuf(char_type* __s, streamsize __n)

      {

	if (__s && __n >= 0)

	  {

	    // This is implementation-defined behavior, and assumes

	    // that an external char_type array of length __n exists

	    // and has been pre-allocated. If this is not the case,

	    // things will quickly blow up.

	    // Step 1: Destroy the current internal array.

	    _M_string = __string_type(__s, __n);

	    // Step 2: Use the external array.

	    _M_sync(__s, 0, 0);

	  }

	return this;

      }

      // [documentation is inherited]

      virtual pos_type

      seekoff(off_type __off, ios_base::seekdir __way,

	      ios_base::openmode __mode = ios_base::in | ios_base::out);

      // [documentation is inherited]

      virtual pos_type

      seekpos(pos_type __sp,

	      ios_base::openmode __mode = ios_base::in | ios_base::out);

      // Internal function for correctly updating the internal buffer

      // for a particular _M_string, due to initialization or

      // re-sizing of an existing _M_string.

      // Assumes: contents of _M_string and internal buffer match exactly.

      // __i == _M_in_cur - _M_in_beg

      // __o == _M_out_cur - _M_out_beg

      /**

       *  @if maint

       *  @doctodo

       *  @endif

      */

      void

      _M_sync(char_type* __base, __size_type __i, __size_type __o)

      {

	const bool __testin = this->_M_mode & ios_base::in;

	const bool __testout = this->_M_mode & ios_base::out;

	const __size_type __len = _M_string.size();

	if (__testin)

	  this->setg(__base, __base + __i, __base + __len);

	if (__testout)

	  {

	    this->setp(__base, __base + _M_string.capacity());

	    this->pbump(__o);

	    // We need a pointer to the string end anyway, even when

	    // !__testin: in that case, however, for the correct

	    // functioning of the streambuf inlines all the get area

	    // pointers must be identical.

	    if (!__testin)

	      this->setg(__base + __len, __base + __len, __base + __len);

	  }

      }

      // Internal function for correctly updating egptr() to the actual

      // string end.

      void

      _M_update_egptr()

      {

	const bool __testin = this->_M_mode & ios_base::in;

	if (this->pptr() && this->pptr() > this->egptr())

	  if (__testin)

	    this->setg(this->eback(), this->gptr(), this->pptr());

	  else

	    this->setg(this->pptr(), this->pptr(), this->pptr());

      }

    };

  // [27.7.2] Template class basic_istringstream

  /**

   *  @brief  Controlling input for std::string.

   *

   *  This class supports reading from objects of type std::basic_string,

   *  using the inherited functions from std::basic_istream.  To control

   *  the associated sequence, an instance of std::basic_stringbuf is used,

   *  which this page refers to as @c sb.

  */

  template<typename _CharT, typename _Traits, typename _Alloc>

    class basic_istringstream : public basic_istream<_CharT, _Traits>

    {

    public:

      // Types:

      typedef _CharT 					char_type;

      typedef _Traits 					traits_type;

      // _GLIBCXX_RESOLVE_LIB_DEFECTS

      // 251. basic_stringbuf missing allocator_type

      typedef _Alloc				       	allocator_type;

      typedef typename traits_type::int_type 		int_type;

      typedef typename traits_type::pos_type 		pos_type;

      typedef typename traits_type::off_type 		off_type;

      // Non-standard types:

      typedef basic_string<_CharT, _Traits, _Alloc> 	__string_type;

      typedef basic_stringbuf<_CharT, _Traits, _Alloc> 	__stringbuf_type;

      typedef basic_istream<char_type, traits_type>	__istream_type;

    private:

      /**

       *  @if maint

       *  @doctodo

       *  @endif

      */

      __stringbuf_type	_M_stringbuf;

    public:

      // Constructors:

      /**

       *  @brief  Default constructor starts with an empty string buffer.

       *  @param  mode  Whether the buffer can read, or write, or both.

       *

       *  @c ios_base::in is automatically included in @a mode.

       *

       *  Initializes @c sb using @c mode|in, and passes @c &sb to the base

       *  class initializer.  Does not allocate any buffer.

       *

       *  @if maint

       *  That's a lie.  We initialize the base class with NULL, because the

       *  string class does its own memory management.

       *  @endif

      */

      explicit

      basic_istringstream(ios_base::openmode __mode = ios_base::in)

      : __istream_type(), _M_stringbuf(__mode | ios_base::in)

      { this->init(&_M_stringbuf); }

      /**

       *  @brief  Starts with an existing string buffer.

       *  @param  str  A string to copy as a starting buffer.

       *  @param  mode  Whether the buffer can read, or write, or both.

       *

       *  @c ios_base::in is automatically included in @a mode.

       *

       *  Initializes @c sb using @a str and @c mode|in, and passes @c &sb

       *  to the base class initializer.

       *

       *  @if maint

       *  That's a lie.  We initialize the base class with NULL, because the

       *  string class does its own memory management.

       *  @endif

      */

      explicit

      basic_istringstream(const __string_type& __str,

			  ios_base::openmode __mode = ios_base::in)

      : __istream_type(), _M_stringbuf(__str, __mode | ios_base::in)

      { this->init(&_M_stringbuf); }

      /**

       *  @brief  The destructor does nothing.

       *

       *  The buffer is deallocated by the stringbuf object, not the

       *  formatting stream.

      */

      ~basic_istringstream()

      { }

      // Members:

      /**

       *  @brief  Accessing the underlying buffer.

       *  @return  The current basic_stringbuf buffer.

       *

       *  This hides both signatures of std::basic_ios::rdbuf().

      */

      __stringbuf_type*

      rdbuf() const

      { return const_cast<__stringbuf_type*>(&_M_stringbuf); }

      /**

       *  @brief  Copying out the string buffer.

       *  @return  @c rdbuf()->str()

      */

      __string_type

      str() const

      { return _M_stringbuf.str(); }

      /**

       *  @brief  Setting a new buffer.

       *  @param  s  The string to use as a new sequence.

       *

       *  Calls @c rdbuf()->str(s).

      */

      void

      str(const __string_type& __s)

      { _M_stringbuf.str(__s); }

    };

  // [27.7.3] Template class basic_ostringstream

  /**

   *  @brief  Controlling output for std::string.

   *

   *  This class supports writing to objects of type std::basic_string,

   *  using the inherited functions from std::basic_ostream.  To control

   *  the associated sequence, an instance of std::basic_stringbuf is used,

   *  which this page refers to as @c sb.

  */

  template <typename _CharT, typename _Traits, typename _Alloc>

    class basic_ostringstream : public basic_ostream<_CharT, _Traits>

    {

    public:

      // Types:

      typedef _CharT 					char_type;

      typedef _Traits 					traits_type;

      // _GLIBCXX_RESOLVE_LIB_DEFECTS

      // 251. basic_stringbuf missing allocator_type

      typedef _Alloc				       	allocator_type;

      typedef typename traits_type::int_type 		int_type;

      typedef typename traits_type::pos_type 		pos_type;

      typedef typename traits_type::off_type 		off_type;

      // Non-standard types:

      typedef basic_string<_CharT, _Traits, _Alloc> 	__string_type;

      typedef basic_stringbuf<_CharT, _Traits, _Alloc> 	__stringbuf_type;

      typedef basic_ostream<char_type, traits_type>	__ostream_type;

    private:

      /**

       *  @if maint

       *  @doctodo

       *  @endif

      */

      __stringbuf_type	_M_stringbuf;

    public:

      // Constructors/destructor:

      /**

       *  @brief  Default constructor starts with an empty string buffer.

       *  @param  mode  Whether the buffer can read, or write, or both.

       *

       *  @c ios_base::out is automatically included in @a mode.

       *

       *  Initializes @c sb using @c mode|out, and passes @c &sb to the base

       *  class initializer.  Does not allocate any buffer.

       *

       *  @if maint

       *  That's a lie.  We initialize the base class with NULL, because the

       *  string class does its own memory management.

       *  @endif

      */

      explicit

      basic_ostringstream(ios_base::openmode __mode = ios_base::out)

      : __ostream_type(), _M_stringbuf(__mode | ios_base::out)

      { this->init(&_M_stringbuf); }

      /**

       *  @brief  Starts with an existing string buffer.

       *  @param  str  A string to copy as a starting buffer.

       *  @param  mode  Whether the buffer can read, or write, or both.

       *

       *  @c ios_base::out is automatically included in @a mode.

       *

       *  Initializes @c sb using @a str and @c mode|out, and passes @c &sb

       *  to the base class initializer.

       *

       *  @if maint

       *  That's a lie.  We initialize the base class with NULL, because the

       *  string class does its own memory management.

       *  @endif

      */

      explicit

      basic_ostringstream(const __string_type& __str,

			  ios_base::openmode __mode = ios_base::out)

      : __ostream_type(), _M_stringbuf(__str, __mode | ios_base::out)

      { this->init(&_M_stringbuf); }

      /**

       *  @brief  The destructor does nothing.

       *

       *  The buffer is deallocated by the stringbuf object, not the

       *  formatting stream.

      */

      ~basic_ostringstream()

      { }

      // Members:

      /**

       *  @brief  Accessing the underlying buffer.

       *  @return  The current basic_stringbuf buffer.

       *

       *  This hides both signatures of std::basic_ios::rdbuf().

      */

      __stringbuf_type*

      rdbuf() const

      { return const_cast<__stringbuf_type*>(&_M_stringbuf); }

      /**

       *  @brief  Copying out the string buffer.

       *  @return  @c rdbuf()->str()

      */

      __string_type

      str() const

      { return _M_stringbuf.str(); }

      /**

       *  @brief  Setting a new buffer.

       *  @param  s  The string to use as a new sequence.

       *

       *  Calls @c rdbuf()->str(s).

      */

      void

      str(const __string_type& __s)

      { _M_stringbuf.str(__s); }

    };

  // [27.7.4] Template class basic_stringstream

  /**

   *  @brief  Controlling input and output for std::string.

   *