pub fn new(rng: &'a mut R, weights: &[T]) -> Result<Self, WeightedShuffleError<T>> {
        let size = weights.len() + 1;
        let zero = <T as Default>::default();
        let mut arr = vec![zero; size];
        let mut sum = zero;
        for (mut k, &weight) in (1usize..).zip(weights) {
            #[allow(clippy::neg_cmp_op_on_partial_ord)]
            // weight < zero does not work for NaNs.
            if !(weight >= zero) {
                return Err(WeightedShuffleError::NegativeWeight(weight));
            }
            sum = sum
                .checked_add(&weight)
                .ok_or(WeightedShuffleError::SumOverflow)?;
            while k < size {
                arr[k] += weight;
                k += k & k.wrapping_neg();
            }
        }
        Ok(Self { arr, sum, rng })
    }
/// Returns error if:
///   - any of the weights are negative.
///   - sum of weights overflows.
Returns error if:
any of the weights are negative.
sum of weights overflows.
Returns error if : any of the weights are negative . sum of weights overflows .
pub fn new(rng: &'a mut R, weights: &[T]) -> Result<Self, WeightedShuffleError<T>> {
        let size = weights.len() + 1;
        let zero = <T as Default>::default();
        let mut arr = vec![zero; size];
        let mut sum = zero;
        for (mut k, &weight) in (1usize..).zip(weights) {
            #[allow(clippy::neg_cmp_op_on_partial_ord)]
            // weight < zero does not work for NaNs.
            if !(weight >= zero) {
                return Err(WeightedShuffleError::NegativeWeight(weight));
            }
            sum = sum
                .checked_add(&weight)
                .ok_or(WeightedShuffleError::SumOverflow)?;
            while k < size {
                arr[k] += weight;
                k += k & k.wrapping_neg();
            }
        }
        Ok(Self { arr, sum, rng })
    }
pub fn new ( rng : & ' a mut R , weights : & [ T ] ) -> Result < Self , WeightedShuffleError < T > > { let size = weights . len ( ) + 1 ; let zero = < T as Default > :: default ( ) ; let mut arr = vec ! [ zero size ] ; let mut sum = zero ; for ( mut k , & weight ) in ( 1usize .. ) . zip ( weights ) { # [ allow ( clippy neg_cmp_op_on_partial_ord ) ] // weight < zero does not work for NaNs. if ! ( weight >= zero ) { return Err ( WeightedShuffleError :: NegativeWeight ( weight ) ) ; } sum = sum . checked_add ( & weight ) . ok_or ( WeightedShuffleError :: SumOverflow ) ? ; while k < size { arr [ k ] += weight ; k += k & k . wrapping_neg ( ) ; } } Ok ( Self { arr , sum , rng } ) }
Returns error if:
 any of the weights are negative.
Returns error if : any of the weights are negative .
rng
&'a mut R
weights
&[T]