bufferstream.hpp

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      }

      if(out) {
         std::ptrdiff_t n = this->epptr() - this->pbase();

         if(off < 0 || off > n)
            return pos_type(off_type(-1));
         else {
            this->setp(this->pbase(), this->pbase() + n);
            this->pbump(off);
         }
      }

      return pos_type(off);
   }

   virtual pos_type seekpos(pos_type pos, std::ios_base::openmode mode 
                                 = std::ios_base::in | std::ios_base::out)
   {  return seekoff(pos - pos_type(off_type(0)), std::ios_base::beg, mode);  }

   private:
   std::ios_base::openmode m_mode;
   CharT *                 m_buffer;
   std::size_t             m_length;
   /// @endcond
};

//!A basic_istream class that uses a fixed size character buffer
//!as its formatting buffer.
template <class CharT, class CharTraits>
class basic_ibufferstream
   : public std::basic_istream<CharT, CharTraits>
{
   public:                         // Typedefs
   typedef typename std::basic_ios
      <CharT, CharTraits>::char_type          char_type;
   typedef typename std::basic_ios<char_type, CharTraits>::int_type     int_type;
   typedef typename std::basic_ios<char_type, CharTraits>::pos_type     pos_type;
   typedef typename std::basic_ios<char_type, CharTraits>::off_type     off_type;
   typedef typename std::basic_ios<char_type, CharTraits>::traits_type  traits_type;

   private:
   typedef std::basic_ios<char_type, CharTraits>                basic_ios_t;
   typedef std::basic_istream<char_type, CharTraits>            base_t;

   public:
   //!Constructor.
   //!Does not throw.
   basic_ibufferstream(std::ios_base::openmode mode = std::ios_base::in)
      :  basic_ios_t(), base_t(0), m_buf(mode | std::ios_base::in)
      {  basic_ios_t::init(&m_buf); }

   //!Constructor. Assigns formatting buffer.
   //!Does not throw.
   basic_ibufferstream(const CharT *buffer, std::size_t length,
                          std::ios_base::openmode mode = std::ios_base::in)
      :  basic_ios_t(), base_t(0), 
         m_buf(const_cast<CharT*>(buffer), length, mode | std::ios_base::in)
      {  basic_ios_t::init(&m_buf); }

   ~basic_ibufferstream(){};

   public:
   //!Returns the address of the stored
   //!stream buffer.
   basic_bufferbuf<CharT, CharTraits>* rdbuf() const
      { return const_cast<basic_bufferbuf<CharT, CharTraits>*>(&m_buf); }

   //!Returns the pointer and size of the internal buffer. 
   //!Does not throw.
   std::pair<const CharT *, std::size_t> buffer() const
      { return m_buf.buffer(); }

   //!Sets the underlying buffer to a new value. Resets 
   //!stream position. Does not throw.
   void buffer(const CharT *buffer, std::size_t length)
      {  m_buf.buffer(const_cast<CharT*>(buffer), length);  }

   /// @cond
   private:
   basic_bufferbuf<CharT, CharTraits> m_buf;
   /// @endcond
};

//!A basic_ostream class that uses a fixed size character buffer
//!as its formatting buffer.
template <class CharT, class CharTraits>
class basic_obufferstream
   : public std::basic_ostream<CharT, CharTraits>
{
   public:
   typedef typename std::basic_ios
      <CharT, CharTraits>::char_type          char_type;
   typedef typename std::basic_ios<char_type, CharTraits>::int_type     int_type;
   typedef typename std::basic_ios<char_type, CharTraits>::pos_type     pos_type;
   typedef typename std::basic_ios<char_type, CharTraits>::off_type     off_type;
   typedef typename std::basic_ios<char_type, CharTraits>::traits_type  traits_type;

   /// @cond
   private:
   typedef std::basic_ios<char_type, CharTraits>      basic_ios_t;
   typedef std::basic_ostream<char_type, CharTraits>  base_t;
   /// @endcond
   public:
   //!Constructor.
   //!Does not throw.
   basic_obufferstream(std::ios_base::openmode mode = std::ios_base::out)
      :  basic_ios_t(), base_t(0), m_buf(mode | std::ios_base::out)
      {  basic_ios_t::init(&m_buf); }

   //!Constructor. Assigns formatting buffer.
   //!Does not throw.
   basic_obufferstream(CharT *buffer, std::size_t length,
                       std::ios_base::openmode mode = std::ios_base::out)
      :  basic_ios_t(), base_t(0), 
         m_buf(buffer, length, mode | std::ios_base::out)
      {  basic_ios_t::init(&m_buf); }

   ~basic_obufferstream(){}

   public:
   //!Returns the address of the stored
   //!stream buffer.
   basic_bufferbuf<CharT, CharTraits>* rdbuf() const
      { return const_cast<basic_bufferbuf<CharT, CharTraits>*>(&m_buf); }

   //!Returns the pointer and size of the internal buffer. 
   //!Does not throw.
   std::pair<CharT *, std::size_t> buffer() const
      { return m_buf.buffer(); }

   //!Sets the underlying buffer to a new value. Resets 
   //!stream position. Does not throw.
   void buffer(CharT *buffer, std::size_t length)
      {  m_buf.buffer(buffer, length);  }

   /// @cond
   private:
   basic_bufferbuf<CharT, CharTraits> m_buf;
   /// @endcond
};


//!A basic_iostream class that uses a fixed size character buffer
//!as its formatting buffer.
template <class CharT, class CharTraits>
class basic_bufferstream 
   : public std::basic_iostream<CharT, CharTraits>

{
   public:                         // Typedefs
   typedef typename std::basic_ios
      <CharT, CharTraits>::char_type          char_type;
   typedef typename std::basic_ios<char_type, CharTraits>::int_type     int_type;
   typedef typename std::basic_ios<char_type, CharTraits>::pos_type     pos_type;
   typedef typename std::basic_ios<char_type, CharTraits>::off_type     off_type;
   typedef typename std::basic_ios<char_type, CharTraits>::traits_type  traits_type;

   /// @cond
   private:
   typedef std::basic_ios<char_type, CharTraits>                 basic_ios_t;
   typedef std::basic_iostream<char_type, CharTraits>            base_t;
   /// @endcond

   public:
   //!Constructor.
   //!Does not throw.
   basic_bufferstream(std::ios_base::openmode mode 
                      = std::ios_base::in | std::ios_base::out)
      :  basic_ios_t(), base_t(0), m_buf(mode)
      {  basic_ios_t::init(&m_buf); }

   //!Constructor. Assigns formatting buffer.
   //!Does not throw.
   basic_bufferstream(CharT *buffer, std::size_t length,
                      std::ios_base::openmode mode
                        = std::ios_base::in | std::ios_base::out)
      :  basic_ios_t(), base_t(0), m_buf(buffer, length, mode)
      {  basic_ios_t::init(&m_buf); }

   ~basic_bufferstream(){}

   public:
   //!Returns the address of the stored
   //!stream buffer.
   basic_bufferbuf<CharT, CharTraits>* rdbuf() const
      { return const_cast<basic_bufferbuf<CharT, CharTraits>*>(&m_buf); }

   //!Returns the pointer and size of the internal buffer. 
   //!Does not throw.
   std::pair<CharT *, std::size_t> buffer() const
      { return m_buf.buffer(); }

   //!Sets the underlying buffer to a new value. Resets 
   //!stream position. Does not throw.
   void buffer(CharT *buffer, std::size_t length)
      {  m_buf.buffer(buffer, length);  }

   /// @cond
   private:
   basic_bufferbuf<CharT, CharTraits> m_buf;
   /// @endcond
};

//Some typedefs to simplify usage
typedef basic_bufferbuf<char>        bufferbuf;
typedef basic_bufferstream<char>     bufferstream;
typedef basic_ibufferstream<char>    ibufferstream;
typedef basic_obufferstream<char>    obufferstream;

typedef basic_bufferbuf<wchar_t>     wbufferbuf;
typedef basic_bufferstream<wchar_t>  wbufferstream;
typedef basic_ibufferstream<wchar_t> wibufferstream;
typedef basic_obufferstream<wchar_t> wobufferstream;


}} //namespace boost {  namespace interprocess {

#include <boost/interprocess/detail/config_end.hpp>

#endif /* BOOST_INTERPROCESS_BUFFERSTREAM_HPP */