/*
 *  call-seq:
 *     bv.count -> bit_count
 *  
 *  Count the number of bits set in the bit vector. If the bit vector has been
 *  negated using +#not+ then count the number of unset bits
 *  instead.
 */
VALUE
frt_bv_count(VALUE self)
{
    BitVector *bv;
    GET_BV(bv, self);
    return INT2FIX(bv->count);
}