The representation of a packed array type created using Of_binable
is a Bin_prot
buffer and a packed array of indices pointing to the beginning of each serialized
element in the buffer.
This function only needs implementation if t
exposed to be a polymorphic variant.
Despite what the type reads, this does *not* produce a function after reading;
instead it takes the constructor tag (int) before reading and reads the rest of the
variant t
afterwards.