gistfile1.txt

public static unsafe ushort ReadUShort(ref this ByteBufferReader reader)
        {
            var firstSpan = reader.UnreadSegment;
            ushort returnValue;
            if (firstSpan.Length >= 2)
            {
                returnValue = BinaryPrimitives.ReadUInt16BigEndian(firstSpan);
            }
            else
            {

                var temp = (Span<byte>)stackalloc byte[2];
                BufferReader.Peek(reader, temp);
                returnValue = BinaryPrimitives.ReadUInt16BigEndian(temp);
            }
            reader.Advance(2);
            return returnValue;
        }