Here are the data structures with brief descriptions:

C_ion_collection
C_ion_collection_node
C_ion_decimal
C_ion_extractor_options
C_ion_int
C_ion_reader_context_change_notifier
C_ion_reader_options
C_ion_string
C_ion_symbol
C_ion_symbol_import_location
C_ion_timestamp
C_ion_user_stream
C_ion_writer_options