Enum bellframe::Parity

#[repr(u8)]
pub enum Parity {
    Even,
    Odd,
}

Data type representing the parity of a Row. To generate these, you probably want to use Row::parity. Note that Row::parity always performs a heap allocation and is linear-time in the Stage of the Row. If you are using Paritys as optimisations within hot code I would recommend computing them upfront on your input Rows and then tracking them by hand, probably using the * operator.

Note that it would be quite cheap for Rows to track their Parity all the time, but that would result in less-than ideal data layouts and doesn’t fit with the ‘only pay for what you use’ design goal of this library.

Variants

Even

A given Row requires an even number of swaps to return to rounds. This is also often called in course or positive. The parity of rounds on every Stage.

Odd

A given Row requires an odd number of swaps to return to rounds. This is also often called out of course or negative.

Implementations

impl Parity

pub fn from_is_odd(v: bool) -> Self

Maps true to Parity::Even and false to Parity::Odd. On most machines, this will not actually do anything and be removed by the compiler.

pub fn from_number(v: usize) -> Parity

Returns the Parity of a given number.

pub fn zero_or_one(self) -> u8

Returns the Parity of a given number.

pub fn plus_or_minus(self) -> char

Returns the Parity of a given number.

Trait Implementations

impl Clone for Parity

fn clone(&self) -> Parity

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Parity

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for Parity

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl Mul<Parity> for Parity

fn mul(self, rhs: Self) -> Self::Output

‘Multiply’ two Paritys together (this corresponds to xor/uncarried addition where Even is 0 and Odd is 1). Also, if you have a Row r1 with Parity p1 and another Row r2 with Parity p2 then (r1 * r2).parity() will always equal p1 * p2. Thus, this can be used to convert calls to Row::parity into an extremely cheap (likely single-cycle) update function.

type Output = Parity

The resulting type after applying the * operator.

impl PartialEq<Parity> for Parity

fn eq(&self, other: &Parity) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=.

impl Copy for Parity

impl Eq for Parity

impl StructuralEq for Parity

impl StructuralPartialEq for Parity