bitio.hh

// Eriksen Liu

/*
 * A pair of simple classes tu perform stream I/O on individual bits.
 */
#include <iostream>

// BitInput: Read a single bit at a time from an input stream.
// Before reading any bits, ensure your input stream still has valid inputs.
class BitInput
{
public:
  // Construct with an input stream
  BitInput(std::istream &is);

  BitInput(const BitInput &) = default;
  BitInput(BitInput &&) = default;
  BitInput &operator=(const BitInput &) = default;
  BitInput &operator=(BitInput &&) = default;

  // Read a single bit (or trailing zero)
  // Allowed to crash or throw an exception if called past end-of-file.
  bool input_bit();

private:
  std::istream &in; // store istream&
  u_int8_t buf;     // store a character from the istream&
  int nbits;        // counter
};

// BitOutput: Write a single bit at a time to an output stream
// Make sure all bits are written out by the time the destructor is done.
class BitOutput
{
public:
  // Construct with an input stream
  BitOutput(std::ostream &os);

  // Flushes out any remaining output bits and trailing zeros, if any:
  ~BitOutput();

  BitOutput(const BitOutput &) = default;
  BitOutput(BitOutput &&) = default;
  BitOutput &operator=(const BitOutput &) = default;
  BitOutput &operator=(BitOutput &&) = default;

  // Output a single bit (buffered)
  void output_bit(bool bit);

private:
  std::ostream &out; // store ostream&
  u_int8_t buf;      // store one character
  int nbits;         // counter
};