bit_stream.hpp

#pragma once
 
#include "fly/types/bit_stream/detail/concepts.hpp"
#include "fly/types/bit_stream/types.hpp"
 
#include <limits>
#include <streambuf>
 
namespace fly::detail {
 
class BitStream
{
public:
    virtual ~BitStream();
 
protected:
    BitStream(std::streambuf *stream_buffer, byte_type starting_position) noexcept;
 
    template <detail::BitStreamInteger DataType>
    DataType bit_mask(const DataType bits);
 
    std::streambuf *m_stream_buffer;
 
    buffer_type m_buffer {0};
    byte_type m_position {0};
};
 
//==================================================================================================
template <detail::BitStreamInteger DataType>
inline DataType BitStream::bit_mask(const DataType bits)
{
    static constexpr auto s_filled = std::numeric_limits<DataType>::max();
    static constexpr auto s_digits = std::numeric_limits<DataType>::digits;
 
    return (bits == 0) ? 0 : s_filled >> (s_digits - bits);
}
 
} // namespace fly::detail