Trait num_traits::One

pub trait One: Mul<Self, Output = Self> {
    fn one() -> Self;

    fn set_one(&mut self) { ... }
    fn is_one(&self) -> bool
    where
        Self: PartialEq<Self>,
    { ... }
}

Defines a multiplicative identity element for Self.

Laws

a * 1 = a       ∀ a ∈ Self
1 * a = a       ∀ a ∈ Self

Required methods

fn one() -> Self

Returns the multiplicative identity element of Self, 1.

Purity

This function should return the same result at all times regardless of external mutable state, for example values stored in TLS or in static muts.

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Provided methods

fn set_one(&mut self)

Sets self to the multiplicative identity element of Self, 1.

fn is_one(&self) -> bool where
    Self: PartialEq<Self>, 

Returns true if self is equal to the multiplicative identity.

For performance reasons, it's best to implement this manually. After a semver bump, this method will be required, and the where Self: PartialEq bound will be removed.

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Implementations on Foreign Types

impl One for i8

pub fn one() -> i8

pub fn is_one(&self) -> bool

impl One for usize

pub fn one() -> usize

pub fn is_one(&self) -> bool

impl One for f32

pub fn one() -> f32

pub fn is_one(&self) -> bool

impl One for f64

pub fn one() -> f64

pub fn is_one(&self) -> bool

impl One for i64

pub fn one() -> i64

pub fn is_one(&self) -> bool

impl One for i32

pub fn one() -> i32

pub fn is_one(&self) -> bool

impl One for i16

pub fn one() -> i16

pub fn is_one(&self) -> bool

impl One for u128

pub fn one() -> u128

pub fn is_one(&self) -> bool

impl One for i128

pub fn one() -> i128

pub fn is_one(&self) -> bool

impl One for isize

pub fn one() -> isize

pub fn is_one(&self) -> bool

impl<T> One for Wrapping<T> where
    T: One,
    Wrapping<T>: Mul<Wrapping<T>>,
    <Wrapping<T> as Mul<Wrapping<T>>>::Output == Wrapping<T>, 

pub fn set_one(&mut self)

pub fn one() -> Wrapping<T>

impl One for u32

pub fn one() -> u32

pub fn is_one(&self) -> bool

impl One for u64

pub fn one() -> u64

pub fn is_one(&self) -> bool

impl One for u16

pub fn one() -> u16

pub fn is_one(&self) -> bool

impl One for u8

pub fn one() -> u8

pub fn is_one(&self) -> bool

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Implementors

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