Struct NonMinUsize 

pub struct NonMinUsize { /* private fields */ }

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

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

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

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

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

Implementations

impl NonMinUsize

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

Creates an instance of NonMinUsize by checking if the value is not usize::MIN.

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

Creates an instance of NonMinUsize without checking if the value is not usize::MIN.

Safety

The value cannot be equal to usize::MIN.

pub fn get(self) -> usize

Returns the integer value.

Trait Implementations

impl Clone for NonMinUsize

fn clone(&self) -> NonMinUsize

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for NonMinUsize

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

Formats the value using the given formatter.

impl Display for NonMinUsize

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

Formats the value using the given formatter.

impl From<NonMinUsize> for usize

fn from(nontype: NonMinUsize) -> Self

Converts to this type from the input type.

impl Hash for NonMinUsize

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, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for NonMinUsize

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

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for NonMinUsize

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for NonMinUsize

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

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

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl Copy for NonMinUsize

impl Eq for NonMinUsize

impl StructuralPartialEq for NonMinUsize