| Cpn_atom_t | A discriminated union that holds any scalar AMQP value |
| Cpn_bytes_t | A const byte buffer |
| Cpn_connection_driver_t | The elements needed to drive AMQP IO and events |
| Cpn_decimal128_t | A 128-bit decimal floating-point number |
| Cpn_raw_buffer_t | A descriptor used to represent a single raw buffer in memory |
| Cpn_rwbytes_t | A non-const byte buffer |
| Cpn_uuid_t | A 16-byte universally unique identifier |