Binary serialization, the smarter way: reloaded

public sealed class BinaryHelper
{
	private enum TypeID : byte
	{
		Boolean = 0x03, 
		Byte = 0x06, 
		...
	}

	private static Type[] _types;

	static IOHelper()
	{
		_types = new Type[19];
		_types[0] = typeof(string);
		_types[1] = typeof(int);
		_types[2] = typeof(bool);
		...
	}

	private BinaryHelper(){}

	public static object ReadBinary(BinaryReader reader)
	{
		TypeID code = (TypeID) reader.ReadByte();

		switch (code)
		{
			case TypeID.Boolean:
				return reader.ReadBoolean();
			case TypeID.Byte:
				return reader.ReadByte();
			...
			case TypeID.Object:
				BinaryFormatter fmt = new BinaryFormatter();
				MemoryStream stm = new MemoryStream(reader.ReadBytes(reader.ReadInt32()));
				return fmt.Deserialize(stm);
			...
		}
	}

	public static void WriteBinary(BinaryWriter writer, object value)
	{
		if (value == null)
		{
			writer.Write((byte)TypeID.Null);
			return;
		}

		Type t = value.GetType();
		//Write according to type.

		if (t == _types[0])
		{
			writer.Write((byte)TypeID.String);
			writer.Write((String)value);
			return;
		}
		if (t == _types[1])
		{
			writer.Write((byte)TypeID.Int32);
			writer.Write((int)value);
			return;
		}
		...
		//Other types serialized to binary directly.
		try
		{
			writer.Write((byte)TypeID.Object);
			BinaryFormatter fmt = new BinaryFormatter();
			MemoryStream stm = new MemoryStream();
			fmt.Serialize(stm, value);
			writer.Write(stm.Length);
			writer.Write(stm.ToArray());
		}
		catch (Exception ex)
		{
			throw new InvalidOperationException("Couldn't serialize object.", ex);
		}
	}
}