Bit writer

using System;
using System.IO;

namespace BitStream
{
    public class BitWriter : IDisposable
    {
        private readonly Stream _outStream;
        private byte _buf;
        private int _counter;

        public BitWriter(Stream outStream)
        {
            _outStream = outStream;
        }

        public void Write(bool bit)
        {
            _counter++;
            _buf <<= 1;
            _buf |= (bit ? (byte) 1 : (byte) 0);

            if (_counter == 8)
            {
                Flush();
            }
        }

        private void Flush()
        {
            if (_counter == 0) return;

            _buf <<= 8 - _counter;
            _counter = 0;
            _outStream.WriteByte(_buf);
            _buf = 0;
        }

        public void Dispose()
        {
            Flush();
            _outStream.Dispose();
        }
    }

    class Program
    {
        static void Main(string[] args)
        {
            using (var bs = new BitWriter(new FileStream("test.bin", FileMode.Truncate)))
            {
                for (var i = 0; i < 16; i++)
                {
                    bs.Write(i % 2 == 0);
                }
            }
        }
    }
}