The bin-prot representation of lengths of strings, arrays, etc.
include sig ... endval bin_t : t Bin_prot.Type_class.tval bin_read_t : t Bin_prot.Read.readerval __bin_read_t__ : (int ‑> t) Bin_prot.Read.readerval bin_reader_t : t Bin_prot.Type_class.readerval bin_size_t : t Bin_prot.Size.sizerval bin_write_t : t Bin_prot.Write.writerval bin_writer_t : t Bin_prot.Type_class.writerval bin_shape_t : Bin_prot.Shape.t