Trait num::traits::identities::One

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

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

Defines a multiplicative identity element for Self.

Required methods

fn one() -> Self

Returns the multiplicative identity element of Self, 1.

Laws

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

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

fn one() -> Wrapping<T>

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

impl One for u64

fn one() -> u64

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

impl One for u32

fn one() -> u32

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

impl One for f32

fn one() -> f32

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

impl One for u16

fn one() -> u16

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

impl One for i16

fn one() -> i16

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

impl One for u8

fn one() -> u8

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

impl One for usize

fn one() -> usize

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

impl One for i64

fn one() -> i64

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

impl One for u128

fn one() -> u128

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

impl One for i32

fn one() -> i32

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

impl One for i8

fn one() -> i8

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

impl One for isize

fn one() -> isize

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

impl One for f64

fn one() -> f64

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

impl One for i128

fn one() -> i128

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

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Implementors

impl One for BigInt

fn one() -> BigInt

fn is_one(&self) -> bool

impl One for BigUint

fn one() -> BigUint

fn is_one(&self) -> bool

impl<T> One for Complex<T> where
    T: Clone + Num, 

fn one() -> Complex<T>

fn is_one(&self) -> bool

impl<T> One for Ratio<T> where
    T: Clone + Integer, 

fn one() -> Ratio<T>

fn is_one(&self) -> bool

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