MongoDB.Bson.Serialization.Serializers.SByteSerializer.Deserialize C# (CSharp) Method

        public override object Deserialize(
            BsonReader bsonReader,
            Type nominalType,
            Type actualType,
            IBsonSerializationOptions options)
        {
            VerifyTypes(nominalType, actualType, typeof(sbyte));

            var bsonType = bsonReader.GetCurrentBsonType();
            var lostData = false;
            sbyte value;
            switch (bsonType)
            {
                case BsonType.Binary:
                    var bytes = bsonReader.ReadBytes();
                    if (bytes.Length != 1)
                    {
                        throw new Exception("Binary data for SByte must be exactly one byte long.");
                    }
                    value = (sbyte)bytes[0];
                    break;
                case BsonType.Int32:
                    var int32Value = bsonReader.ReadInt32();
                    value = (sbyte)int32Value;
                    lostData = (int)value != int32Value;
                    break;
                case BsonType.Int64:
                    var int64Value = bsonReader.ReadInt64();
                    value = (sbyte)int64Value;
                    lostData = (int)value != int64Value;
                    break;
                case BsonType.String:
                    var s = bsonReader.ReadString();
                    if (s.Length == 1)
                    {
                        s = "0" + s;
                    }
                    value = (sbyte)byte.Parse(s, NumberStyles.HexNumber);
                    break;
                default:
                    var message = string.Format("Cannot deserialize SByte from BsonType {0}.", bsonType);
                    throw new Exception(message);
            }
            if (lostData)
            {
                var message = string.Format("Data loss occurred when trying to convert from {0} to SByte.", bsonType);
                throw new Exception(message);
            }

            return value;
        }