dlib C++ Library - bit_stream_kernel_abstract.h

// Copyright (C) 2003 Davis E. King (davis@dlib.net)
// License: Boost Software License See LICENSE.txt for the full license.
#undef DLIB_BIT_STREAM_KERNEl_ABSTRACT_
#ifdef DLIB_BIT_STREAM_KERNEl_ABSTRACT_
#include <iosfwd>
namespace dlib
{
 class bit_stream
 {
 /*!
 INITIAL VALUE
 is_in_write_mode() == false
 is_in_read_mode() == false
 WHAT THIS OBJECT REPRESENTS
 this object is a middle man between a user and the iostream classes.
 it allows single bits to be read/written easily to/from 
 the iostream classes 
 BUFFERING:
 This object will only read/write single bytes at a time from/to the 
 iostream objects. Any buffered bits still in the bit_stream object 
 when it is closed or destructed are lost if it is in read mode. If 
 it is in write mode then any remaining bits are guaranteed to be 
 written to the output stream by the time it is closed or destructed.
 !*/
 public:
 bit_stream (
 );
 /*!
 ensures 
 - #*this is properly initialized
 throws
 - std::bad_alloc
 !*/
 virtual ~bit_stream (
 );
 /*!
 ensures
 - all memory associated with *this has been released
 !*/
 void clear (
 );
 /*!
 ensures
 - #*this has its initial value
 throws
 - std::bad_alloc
 if this exception is thrown then *this is unusable 
 until clear() is called and succeeds
 !*/
 void set_input_stream (
 std::istream& is
 );
 /*!
 requires
 - is_in_write_mode() == false 
 - is_in_read_mode() == false 
 - is is ready to give input
 ensures 
 - #is_in_write_mode() == false 
 - #is_in_read_mode() == true 
 - #*this will now be reading from is
 throws
 - std::bad_alloc
 !*/
 void set_output_stream (
 std::ostream& os
 );
 /*!
 requires
 - is_in_write_mode() == false 
 - is_in_read_mode() == false 
 - os is ready to take output
 ensures 
 - #is_in_write_mode() == true 
 - #is_in_read_mode() == false 
 - #*this will now write to os
 throws
 - std::bad_alloc
 !*/
 
 void close (
 );
 /*!
 requires
 - is_in_write_mode() == true || is_in_read_mode() == true
 ensures
 - #is_in_write_mode() == false 
 - #is_in_read_mode() == false 
 !*/
 bool is_in_write_mode (
 ) const;
 /*!
 ensures
 - returns true if *this is associated with an output stream object
 - returns false otherwise
 !*/
 bool is_in_read_mode (
 ) const;
 /*!
 ensures
 - returns true if *this is associated with an input stream object
 - returns false otherwise
 !*/
 void write (
 int bit
 );
 /*!
 requires
 - is_in_write_mode() == true 
 - bit == 0 || bit == 1
 ensures
 - bit will be written to the ostream object associated with *this
 throws
 - std::ios_base::failure
 if (there was a problem writing to the output stream) then
 this exception will be thrown. #*this will be unusable until
 clear() is called and succeeds
 - any other exception
 if this exception is thrown then #*this is unusable 
 until clear() is called and succeeds
 !*/
 bool read (
 int& bit
 );
 /*!
 requires
 - is_in_read_mode() == true 
 ensures
 - the next bit has been read and placed into #bit 
 - returns true if the read was successful, else false 
 (ex. false if EOF has been reached)
 throws
 - any exception
 if this exception is thrown then #*this is unusable 
 until clear() is called and succeeds
 !*/
 void swap (
 bit_stream& item
 );
 /*!
 ensures
 - swaps *this and item
 !*/ 
 private:
 // restricted functions
 bit_stream(bit_stream&); // copy constructor
 bit_stream& operator=(bit_stream&); // assignment operator
 };
 inline void swap (
 bit_stream& a, 
 bit_stream& b
 ) { a.swap(b); }
 /*!
 provides a global swap function
 !*/
}
#endif // DLIB_BIT_STREAM_KERNEl_ABSTRACT_