Serialization/Deserialization of avro objects direcly instead of using GenericDatum

to use the serialize function we need to convert my avro object into GenericDatum object , and to do that we need to encode the avro object and then decode it. and in order to send we need to decode the genericDatum agian, it feels like we are doing the same thing twice.
avro lib example :

std::auto_ptr out = avro::memoryOutputStream();
avro::EncoderPtr e = avro::binaryEncoder();
e->init(*out);
c::cpx c1;
c1.re = 100.23;
c1.im = 105.77;
avro::encode(*e, c1);

std::auto_ptr in = avro::memoryInputStream(*out);
avro::DecoderPtr d = avro::binaryDecoder();
d->init(*in);

avro::GenericDatum datum(cpxSchema);
avro::decode(*d, datum);`

instead we can create some global function which look like that :
`template
ssize_t serializeAvro (Schema *schema, const T& avro, std::vector &out, std::string &errstr)`
since avro seralize function doesn't use any of the AvroImpl class members , this look better than the current option. any thoughts ?