Struct core::num::NonZeroUsize

#[repr(transparent)]pub struct NonZeroUsize(_);

An integer that is known not to equal zero.

This enables some memory layout optimization. For example, Option<NonZeroUsize> is the same size as usize:

use std::mem::size_of;
assert_eq!(size_of::<Option<core::num::NonZeroUsize>>(), size_of::<usize>());

Implementations

impl NonZeroUsize

pub const unsafe fn new_unchecked(n: usize) -> Self

Creates a non-zero without checking the value.

Safety

The value must not be zero.

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

Creates a non-zero if the given value is not zero.

pub const fn get(self) -> usize

Returns the value as a primitive type.

impl NonZeroUsize

pub fn leading_zeros(self) -> u32

🔬 This is a nightly-only experimental API. (nonzero_leading_trailing_zeros #79143)

Returns the number of leading zeros in the binary representation of self.

On many architectures, this function can perform better than leading_zeros() on the underlying integer type, as special handling of zero can be avoided.

Examples

Basic usage:

#![feature(nonzero_leading_trailing_zeros)]
let n = std::num::NonZeroUsize::new(usize::MAX).unwrap();

assert_eq!(n.leading_zeros(), 0);

pub fn trailing_zeros(self) -> u32

🔬 This is a nightly-only experimental API. (nonzero_leading_trailing_zeros #79143)

Returns the number of trailing zeros in the binary representation of self.

On many architectures, this function can perform better than trailing_zeros() on the underlying integer type, as special handling of zero can be avoided.

Examples

Basic usage:

#![feature(nonzero_leading_trailing_zeros)]
let n = std::num::NonZeroUsize::new(0b0101000).unwrap();

assert_eq!(n.trailing_zeros(), 3);

impl NonZeroUsize

pub const fn is_power_of_two(self) -> bool

🔬 This is a nightly-only experimental API. (nonzero_is_power_of_two #81106)

Returns true if and only if self == (1 << k) for some k.

On many architectures, this function can perform better than is_power_of_two() on the underlying integer type, as special handling of zero can be avoided.

Examples

Basic usage:

#![feature(nonzero_is_power_of_two)]

let eight = std::num::NonZeroUsize::new(8).unwrap();
assert!(eight.is_power_of_two());
let ten = std::num::NonZeroUsize::new(10).unwrap();
assert!(!ten.is_power_of_two());

Trait Implementations

impl Binary for NonZeroUsize

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

Formats the value using the given formatter.

impl BitOr<NonZeroUsize> for NonZeroUsize

type Output = Self

The resulting type after applying the | operator.

fn bitor(self, rhs: Self) -> Self::Output

Performs the | operation.

impl BitOr<NonZeroUsize> for usize

type Output = NonZeroUsize

The resulting type after applying the | operator.

fn bitor(self, rhs: NonZeroUsize) -> Self::Output

Performs the | operation.

impl BitOr<usize> for NonZeroUsize

type Output = Self

The resulting type after applying the | operator.

fn bitor(self, rhs: usize) -> Self::Output

Performs the | operation.

impl BitOrAssign<NonZeroUsize> for NonZeroUsize

fn bitor_assign(&mut self, rhs: Self)

Performs the |= operation.

impl BitOrAssign<usize> for NonZeroUsize

fn bitor_assign(&mut self, rhs: usize)

Performs the |= operation.

impl Clone for NonZeroUsize

fn clone(&self) -> NonZeroUsize

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for NonZeroUsize

impl Debug for NonZeroUsize

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

Formats the value using the given formatter.

impl Display for NonZeroUsize

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

Formats the value using the given formatter.

impl Div<NonZeroUsize> for usize

type Output = usize

The resulting type after applying the / operator.

fn div(self, other: NonZeroUsize) -> usize

This operation rounds towards zero, truncating any fractional part of the exact result, and cannot panic.

impl Eq for NonZeroUsize

impl From<NonZeroU16> for NonZeroUsize

Converts NonZeroU16 to NonZeroUsize losslessly.

fn from(small: NonZeroU16) -> Self

Performs the conversion.

impl From<NonZeroU8> for NonZeroUsize

Converts NonZeroU8 to NonZeroUsize losslessly.

fn from(small: NonZeroU8) -> Self

Performs the conversion.

impl From<NonZeroUsize> for usize

fn from(nonzero: NonZeroUsize) -> Self

Converts a NonZeroUsize into an usize

impl FromStr for NonZeroUsize

type Err = ParseIntError

The associated error which can be returned from parsing.

fn from_str(src: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl Hash for NonZeroUsize

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H: Hasher>(data: &[Self], state: &mut H) where
    Self: Sized, 

Feeds a slice of this type into the given Hasher.

impl LowerHex for NonZeroUsize

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

Formats the value using the given formatter.

impl Octal for NonZeroUsize

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

Formats the value using the given formatter.

impl Ord for NonZeroUsize

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

This method returns an Ordering between self and other.

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

Compares and returns the maximum of two values.

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

Compares and returns the minimum of two values.

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

Restrict a value to a certain interval.

impl PartialEq<NonZeroUsize> for NonZeroUsize

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

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

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

This method tests for !=.

impl PartialOrd<NonZeroUsize> for NonZeroUsize

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

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

#[must_use]fn lt(&self, other: &Rhs) -> bool

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

#[must_use]fn le(&self, other: &Rhs) -> bool

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

#[must_use]fn gt(&self, other: &Rhs) -> bool

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

#[must_use]fn ge(&self, other: &Rhs) -> bool

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

impl Rem<NonZeroUsize> for usize

type Output = usize

The resulting type after applying the % operator.

fn rem(self, other: NonZeroUsize) -> usize

This operation satisfies n % d == n - (n / d) * d, and cannot panic.

impl StructuralEq for NonZeroUsize

impl StructuralPartialEq for NonZeroUsize

impl TryFrom<NonZeroI128> for NonZeroUsize

Attempts to convert NonZeroI128 to NonZeroUsize.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroI128) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroI16> for NonZeroUsize

Attempts to convert NonZeroI16 to NonZeroUsize.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroI16) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroI32> for NonZeroUsize

Attempts to convert NonZeroI32 to NonZeroUsize.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroI32) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroI64> for NonZeroUsize

Attempts to convert NonZeroI64 to NonZeroUsize.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroI64) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroI8> for NonZeroUsize

Attempts to convert NonZeroI8 to NonZeroUsize.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroI8) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroIsize> for NonZeroUsize

Attempts to convert NonZeroIsize to NonZeroUsize.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroIsize) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroU128> for NonZeroUsize

Attempts to convert NonZeroU128 to NonZeroUsize.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroU128) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroU32> for NonZeroUsize

Attempts to convert NonZeroU32 to NonZeroUsize.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroU32) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroU64> for NonZeroUsize

Attempts to convert NonZeroU64 to NonZeroUsize.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroU64) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroUsize> for NonZeroU8

Attempts to convert NonZeroUsize to NonZeroU8.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroUsize) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroUsize> for NonZeroU16

Attempts to convert NonZeroUsize to NonZeroU16.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroUsize) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroUsize> for NonZeroIsize

Attempts to convert NonZeroUsize to NonZeroIsize.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroUsize) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroUsize> for NonZeroU32

Attempts to convert NonZeroUsize to NonZeroU32.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroUsize) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroUsize> for NonZeroU64

Attempts to convert NonZeroUsize to NonZeroU64.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroUsize) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroUsize> for NonZeroU128

Attempts to convert NonZeroUsize to NonZeroU128.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroUsize) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroUsize> for NonZeroI8

Attempts to convert NonZeroUsize to NonZeroI8.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroUsize) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroUsize> for NonZeroI16

Attempts to convert NonZeroUsize to NonZeroI16.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroUsize) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroUsize> for NonZeroI32

Attempts to convert NonZeroUsize to NonZeroI32.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroUsize) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroUsize> for NonZeroI64

Attempts to convert NonZeroUsize to NonZeroI64.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroUsize) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<NonZeroUsize> for NonZeroI128

Attempts to convert NonZeroUsize to NonZeroI128.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: NonZeroUsize) -> Result<Self, Self::Error>

Performs the conversion.

impl TryFrom<usize> for NonZeroUsize

Attempts to convert usize to NonZeroUsize.

type Error = TryFromIntError

The type returned in the event of a conversion error.

fn try_from(value: usize) -> Result<Self, Self::Error>

Performs the conversion.

impl UpperHex for NonZeroUsize

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

Formats the value using the given formatter.