# 1.28.0[−][src]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>());Run

## Methods

### `impl NonZeroUsize`[src]

#### `pub const unsafe fn new_unchecked(n: usize) -> NonZeroUsize`[src]

Creates a non-zero without checking the value.

# Safety

The value must not be zero.

#### `pub fn new(n: usize) -> Option<NonZeroUsize>`[src]

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

#### `pub const fn get(self) -> usize`[src]

Returns the value as a primitive type.

## Trait Implementations

### `impl Copy for NonZeroUsize`[src]

### `impl UpperHex for NonZeroUsize`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

Formats the value using the given formatter.

### `impl Octal for NonZeroUsize`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

Formats the value using the given formatter.

### `impl PartialOrd<NonZeroUsize> for NonZeroUsize`[src]

#### `fn partial_cmp(&self, other: &NonZeroUsize) -> Option<Ordering>`[src]

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

#### `fn lt(&self, other: &NonZeroUsize) -> bool`[src]

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

#### `fn le(&self, other: &NonZeroUsize) -> bool`[src]

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

#### `fn gt(&self, other: &NonZeroUsize) -> bool`[src]

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

#### `fn ge(&self, other: &NonZeroUsize) -> bool`[src]

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

### `impl Hash for NonZeroUsize`[src]

#### `fn hash<__H>(&self, state: &mut __H) where
__H: Hasher,` [src]

Feeds this value into the given [`Hasher`]. Read more

#### `fn hash_slice<H>(data: &[Self], state: &mut H) where
H: Hasher,` 1.3.0[src]

Feeds a slice of this type into the given [`Hasher`]. Read more

### `impl Binary for NonZeroUsize`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

Formats the value using the given formatter.

### `impl Debug for NonZeroUsize`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

Formats the value using the given formatter. Read more

### `impl Eq for NonZeroUsize`[src]

### `impl Clone for NonZeroUsize`[src]

#### `fn clone(&self) -> NonZeroUsize`[src]

Returns a copy of the value. Read more

#### `fn clone_from(&mut self, source: &Self)`1.0.0[src]

Performs copy-assignment from `source`. Read more

### `impl FromStr for NonZeroUsize` 1.35.0[src]

#### `type Err = ParseIntError`

The associated error which can be returned from parsing.

#### `fn from_str(src: &str) -> Result<NonZeroUsize, <NonZeroUsize as FromStr>::Err>`[src]

Parses a string `s` to return a value of this type. Read more

### `impl Ord for NonZeroUsize`[src]

#### `fn cmp(&self, other: &NonZeroUsize) -> Ordering`[src]

This method returns an `Ordering` between `self` and `other`. Read more

#### `fn max(self, other: Self) -> Self` 1.21.0[src]

Compares and returns the maximum of two values. Read more

#### `fn min(self, other: Self) -> Self` 1.21.0[src]

Compares and returns the minimum of two values. Read more

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

🔬 This is a nightly-only experimental API. (`clamp` #44095)

Restrict a value to a certain interval. Read more

### `impl Display for NonZeroUsize`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

Formats the value using the given formatter. Read more

### `impl LowerHex for NonZeroUsize`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

Formats the value using the given formatter.

### `impl PartialEq<NonZeroUsize> for NonZeroUsize`[src]

#### `fn eq(&self, other: &NonZeroUsize) -> bool`[src]

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

#### `fn ne(&self, other: &NonZeroUsize) -> bool`[src]

This method tests for `!=`.

### `impl From<NonZeroUsize> for usize` 1.31.0[src]

#### `fn from(nonzero: NonZeroUsize) -> usize`[src]

Performs the conversion.

## Auto Trait Implementations

### `impl UnwindSafe for NonZeroUsize`

### `impl RefUnwindSafe for NonZeroUsize`

### `impl Unpin for NonZeroUsize`

### `impl Sync for NonZeroUsize`

### `impl Send for NonZeroUsize`

## Blanket Implementations

### `impl<T, U> TryFrom<U> for T where
U: Into<T>,` [src]

#### `type Error = Infallible`

The type returned in the event of a conversion error.

#### `fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>`[src]

Performs the conversion.

### `impl<T, U> Into<U> for T where
U: From<T>,` [src]

#### `fn into(self) -> U`[src]

Performs the conversion.

### `impl<T> From<T> for T`[src]

#### `fn from(t: T) -> T`[src]

Performs the conversion.

### `impl<T, U> TryInto<U> for T where
U: TryFrom<T>,` [src]

#### `type Error = <U as TryFrom<T>>::Error`

The type returned in the event of a conversion error.

#### `fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>`[src]

Performs the conversion.

### `impl<T> Borrow<T> for T where
T: ?Sized,` [src]

####
ⓘImportant traits for &'_ mut I

### Important traits for &'_ mut I

`impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, R: Read + ?Sized> Read for &'_ mut Rimpl<'_, W: Write + ?Sized> Write for &'_ mut W`
`fn borrow(&self) -> &T`[src]

Immutably borrows from an owned value. Read more

### `impl<T> BorrowMut<T> for T where
T: ?Sized,` [src]

####
ⓘImportant traits for &'_ mut I

### Important traits for &'_ mut I

`impl<'_, I> Iterator for &'_ mut I where
I: Iterator + ?Sized, type Item = <I as Iterator>::Item;impl<'_, F> Future for &'_ mut F where
F: Unpin + Future + ?Sized, type Output = <F as Future>::Output;impl<'_, R: Read + ?Sized> Read for &'_ mut Rimpl<'_, W: Write + ?Sized> Write for &'_ mut W`
`fn borrow_mut(&mut self) -> &mut T`[src]

Mutably borrows from an owned value. Read more

### `impl<T> Any for T where
T: 'static + ?Sized,` [src]

#### `fn type_id(&self) -> TypeId`[src]

Gets the `TypeId` of `self`. Read more

### `impl<T> ToOwned for T where
T: Clone,` [src]

#### `type Owned = T`

The resulting type after obtaining ownership.

#### `fn to_owned(&self) -> T`[src]

Creates owned data from borrowed data, usually by cloning. Read more

#### `fn clone_into(&self, target: &mut T)`[src]

🔬 This is a nightly-only experimental API. (`toowned_clone_into` #41263)

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

### `impl<T> ToString for T where
T: Display + ?Sized,` [src]

#### `default fn to_string(&self) -> String`[src]

Converts the given value to a `String`. Read more

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