Function dds_stream_read_key 

pub unsafe extern "C" fn dds_stream_read_key(
    is: *mut dds_istream_t,
    sample: *mut c_char,
    allocator: *const dds_cdrstream_allocator,
    desc: *const dds_cdrstream_desc,
)

@brief Deserialize serialized key data into sample storage. @component cdr_serializer

Only key fields are populated. The input stream is expected to contain @ref DDS_CDR_KEY_SERIALIZATION_SAMPLE data.

@param is input stream containing serialized key data @param sample destination sample storage @param allocator allocator used for dynamically allocated key members @param desc CDR stream descriptor for the sample type