## `fvect`: operations on vectors, without sanity checks

  This module implements the same functions as the `vect` module, but does not perform bound checks on the arguments of the functions. The functions are therefore faster than those in the `vect` module, but calling these functions with incorrect parameters (that is, parameters that would cause the `Invalid_argument` exception to be raised by the corresponding functions in the `vect` module) can crash the program.