The standard library rw_bit_vector essentially implements a mutable vector of Bools. (For immutable bitvectors see the Bit_Vector API.)
The rw_bit_vector package implements the Rw_Bit_Vector API.
The rw_bit_vector package source code is in src/lib/src/rw-bit-vector.pkg.
The above information is manually maintained and may contain errors.
Rw_Bit_Vector