Struct nonminmax::NonMaxUsize

#[repr(transparent)]
pub struct NonMaxUsize { /* fields omitted */ }

An integer of type usize which is known to not equal usize::MAX.

This type allows for niche filling optimization (similar to the existing std::num::NonZero* types) meaning items such as Option<NonMaxUsize> and Result<NonMaxUsize, ()> take up the same amount of space as usize.

// Create using `new`, extract value using `get`
let x = NonMaxUsize::new(123).unwrap();
assert_eq!(x.get(), 123);

// The value cannot be `usize::MAX`
let y = NonMaxUsize::new(usize::MAX);
assert_eq!(y, None);

// Niche filling optimization works!
use std::mem::size_of;
assert_eq!(size_of::<usize>(), size_of::<NonMaxUsize>());
assert_eq!(size_of::<usize>(), size_of::<Option<NonMaxUsize>>());

Methods

impl NonMaxUsize

pub fn new(value: usize) -> Option<Self>

Creates an instance of NonMaxUsize by checking if the value is not usize::MAX.

pub unsafe fn new_unchecked(value: usize) -> Self

Creates an instance of NonMaxUsize without checking if the value is not usize::MAX.

Safety

The value cannot be equal to usize::MAX.

pub fn get(self) -> usize

Returns the integer value.

Trait Implementations

impl Clone for NonMaxUsize

fn clone(&self) -> NonMaxUsize

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for NonMaxUsize

impl Debug for NonMaxUsize

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

Formats the value using the given formatter.

impl Display for NonMaxUsize

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

Formats the value using the given formatter.

impl Eq for NonMaxUsize

impl From<NonMaxUsize> for usize

fn from(nontype: NonMaxUsize) -> Self

Performs the conversion.

impl Hash for NonMaxUsize

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 Ord for NonMaxUsize

fn cmp(&self, other: &NonMaxUsize) -> Ordering

This method returns an [Ordering] between self and other.

#[must_use] fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use] fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use] fn clamp(self, min: Self, max: Self) -> Self

🔬 This is a nightly-only experimental API. (clamp)

Restrict a value to a certain interval.

impl PartialEq<NonMaxUsize> for NonMaxUsize

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

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

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

This method tests for !=.

impl PartialOrd<NonMaxUsize> for NonMaxUsize

fn partial_cmp(&self, other: &NonMaxUsize) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &NonMaxUsize) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &NonMaxUsize) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &NonMaxUsize) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &NonMaxUsize) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl StructuralEq for NonMaxUsize

impl StructuralPartialEq for NonMaxUsize