Struct std::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) -> NonZeroUsize

Creates a non-zero without checking the value.

Safety

The value must not be zero.

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

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 const fn leading_zeros(self) -> u32

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:

let n = std::num::NonZeroUsize::new(usize::MAX).unwrap();

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

pub const fn trailing_zeros(self) -> u32

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:

let n = std::num::NonZeroUsize::new(0b0101000).unwrap();

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

impl NonZeroUsize

pub 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

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

Formats the value using the given formatter.

impl BitOr<NonZeroUsize> for NonZeroUsize

type Output = NonZeroUsize

The resulting type after applying the | operator.

pub fn bitor(
    self,
    rhs: NonZeroUsize
) -> <NonZeroUsize as BitOr<NonZeroUsize>>::Output

Performs the | operation.

impl BitOr<NonZeroUsize> for usize

type Output = NonZeroUsize

The resulting type after applying the | operator.

pub fn bitor(self, rhs: NonZeroUsize) -> <usize as BitOr<NonZeroUsize>>::Output

Performs the | operation.

impl BitOr<usize> for NonZeroUsize

type Output = NonZeroUsize

The resulting type after applying the | operator.

pub fn bitor(self, rhs: usize) -> <NonZeroUsize as BitOr<usize>>::Output

Performs the | operation.

impl BitOrAssign<NonZeroUsize> for NonZeroUsize

pub fn bitor_assign(&mut self, rhs: NonZeroUsize)

Performs the |= operation.

impl BitOrAssign<usize> for NonZeroUsize

pub fn bitor_assign(&mut self, rhs: usize)

Performs the |= operation.

impl Clone for NonZeroUsize

pub fn clone(&self) -> NonZeroUsize

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for NonZeroUsize

impl Debug for NonZeroUsize

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

Formats the value using the given formatter.

impl Display for NonZeroUsize

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

Formats the value using the given formatter.

impl Div<NonZeroUsize> for usize

type Output = usize

The resulting type after applying the / operator.

pub 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

pub fn from(small: NonZeroU16) -> NonZeroUsize

Converts NonZeroU16 to NonZeroUsize losslessly.

impl From<NonZeroU8> for NonZeroUsize

pub fn from(small: NonZeroU8) -> NonZeroUsize

Converts NonZeroU8 to NonZeroUsize losslessly.

impl From<NonZeroUsize> for usize

pub fn from(nonzero: NonZeroUsize) -> usize

Converts a NonZeroUsize into an usize

impl FromStr for NonZeroUsize

type Err = ParseIntError

The associated error which can be returned from parsing.

pub fn from_str(
    src: &str
) -> Result<NonZeroUsize, <NonZeroUsize as FromStr>::Err>

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

impl Hash for NonZeroUsize

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

Feeds this value into the given Hasher.

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

Feeds a slice of this type into the given Hasher.

impl LowerHex for NonZeroUsize

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

Formats the value using the given formatter.

impl Octal for NonZeroUsize

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

Formats the value using the given formatter.

impl Ord for NonZeroUsize

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

This method returns an Ordering between self and other.

#[must_use]

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

Compares and returns the maximum of two values.

#[must_use]

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

Compares and returns the minimum of two values.

#[must_use]

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

Restrict a value to a certain interval.

impl PartialEq<NonZeroUsize> for NonZeroUsize

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

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

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

This method tests for !=.

impl PartialOrd<NonZeroUsize> for NonZeroUsize

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

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

#[must_use]

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

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

#[must_use]

pub 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]

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

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

#[must_use]

pub 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.

pub 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

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroI128
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroI128>>::Error>

Attempts to convert NonZeroI128 to NonZeroUsize.

impl TryFrom<NonZeroI16> for NonZeroUsize

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroI16
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroI16>>::Error>

Attempts to convert NonZeroI16 to NonZeroUsize.

impl TryFrom<NonZeroI32> for NonZeroUsize

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroI32
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroI32>>::Error>

Attempts to convert NonZeroI32 to NonZeroUsize.

impl TryFrom<NonZeroI64> for NonZeroUsize

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroI64
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroI64>>::Error>

Attempts to convert NonZeroI64 to NonZeroUsize.

impl TryFrom<NonZeroI8> for NonZeroUsize

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroI8
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroI8>>::Error>

Attempts to convert NonZeroI8 to NonZeroUsize.

impl TryFrom<NonZeroIsize> for NonZeroUsize

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroIsize
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroIsize>>::Error>

Attempts to convert NonZeroIsize to NonZeroUsize.

impl TryFrom<NonZeroU128> for NonZeroUsize

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroU128
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroU128>>::Error>

Attempts to convert NonZeroU128 to NonZeroUsize.

impl TryFrom<NonZeroU32> for NonZeroUsize

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroU32
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroU32>>::Error>

Attempts to convert NonZeroU32 to NonZeroUsize.

impl TryFrom<NonZeroU64> for NonZeroUsize

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroU64
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroU64>>::Error>

Attempts to convert NonZeroU64 to NonZeroUsize.

impl TryFrom<NonZeroUsize> for NonZeroI8

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroUsize
) -> Result<NonZeroI8, <NonZeroI8 as TryFrom<NonZeroUsize>>::Error>

Attempts to convert NonZeroUsize to NonZeroI8.

impl TryFrom<NonZeroUsize> for NonZeroU16

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroUsize
) -> Result<NonZeroU16, <NonZeroU16 as TryFrom<NonZeroUsize>>::Error>

Attempts to convert NonZeroUsize to NonZeroU16.

impl TryFrom<NonZeroUsize> for NonZeroU32

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroUsize
) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroUsize>>::Error>

Attempts to convert NonZeroUsize to NonZeroU32.

impl TryFrom<NonZeroUsize> for NonZeroI16

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroUsize
) -> Result<NonZeroI16, <NonZeroI16 as TryFrom<NonZeroUsize>>::Error>

Attempts to convert NonZeroUsize to NonZeroI16.

impl TryFrom<NonZeroUsize> for NonZeroI32

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroUsize
) -> Result<NonZeroI32, <NonZeroI32 as TryFrom<NonZeroUsize>>::Error>

Attempts to convert NonZeroUsize to NonZeroI32.

impl TryFrom<NonZeroUsize> for NonZeroU8

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroUsize
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroUsize>>::Error>

Attempts to convert NonZeroUsize to NonZeroU8.

impl TryFrom<NonZeroUsize> for NonZeroI128

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroUsize
) -> Result<NonZeroI128, <NonZeroI128 as TryFrom<NonZeroUsize>>::Error>

Attempts to convert NonZeroUsize to NonZeroI128.

impl TryFrom<NonZeroUsize> for NonZeroU64

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroUsize
) -> Result<NonZeroU64, <NonZeroU64 as TryFrom<NonZeroUsize>>::Error>

Attempts to convert NonZeroUsize to NonZeroU64.

impl TryFrom<NonZeroUsize> for NonZeroI64

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroUsize
) -> Result<NonZeroI64, <NonZeroI64 as TryFrom<NonZeroUsize>>::Error>

Attempts to convert NonZeroUsize to NonZeroI64.

impl TryFrom<NonZeroUsize> for NonZeroIsize

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroUsize
) -> Result<NonZeroIsize, <NonZeroIsize as TryFrom<NonZeroUsize>>::Error>

Attempts to convert NonZeroUsize to NonZeroIsize.

impl TryFrom<NonZeroUsize> for NonZeroU128

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: NonZeroUsize
) -> Result<NonZeroU128, <NonZeroU128 as TryFrom<NonZeroUsize>>::Error>

Attempts to convert NonZeroUsize to NonZeroU128.

impl TryFrom<usize> for NonZeroUsize

type Error = TryFromIntError

The type returned in the event of a conversion error.

pub fn try_from(
    value: usize
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<usize>>::Error>

Attempts to convert usize to NonZeroUsize.

impl UpperHex for NonZeroUsize

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

Formats the value using the given formatter.