Struct FuncPerm 

pub struct FuncPerm<B> { /* private fields */ }

Cycle-walking functional permutation on [0 . . n), given a bijection on [0 . . m), where m ≥ n.

The bijection must map [0 . . m) to itself. The get method applies the bijection repeatedly until the result falls in [0 . . n), producing a permutation of [0 . . n).

PartialEq, Eq, and Hash cannot be derived because the bijection is typically a closure.

Examples

Using a custom bijection (XOR with a constant on 4-bit values):

let perm = FuncPerm::new(10, |x: u64| x ^ 0b1010);
assert!(perm.get(0) < 10);

Implementations

impl<B> FuncPerm<B>

pub const fn new(n: u64, bijection: B) -> Self

Creates a new cycle-walking functional permutation on [0 . . n) using the given bijection, which must have domain [0 . . m), where m ≥ n.

Note that providing a function that does not satisfy the bijection requirement may lead to non-termination of the get method.

pub const fn len(&self) -> u64

Returns the size of the permutation domain.

pub const fn is_empty(&self) -> bool

Returns true if the permutation domain is empty.

impl<B: Fn(u64) -> u64> FuncPerm<B>

pub fn get(&self, x: u64) -> u64

Returns the image of x under the permutation.

Panics

Panics if x ≥ n.

Trait Implementations

impl<B: Clone> Clone for FuncPerm<B>

fn clone(&self) -> FuncPerm<B>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<B> Debug for FuncPerm<B>

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

Formats the value using the given formatter.

impl<B: Copy> Copy for FuncPerm<B>