Function acb_dot 

pub unsafe extern "C" fn acb_dot(
    res: *mut acb_struct,
    initial: *const acb_struct,
    subtract: c_int,
    x: acb_srcptr,
    xstep: slong,
    y: acb_srcptr,
    ystep: slong,
    len: slong,
    prec: slong,
)