# Struct std::num::NonZeroU32 1.28.0[−][src]

`#[repr(transparent)]pub struct NonZeroU32(_);`

## Expand description

An integer that is known not to equal zero.

This enables some memory layout optimization.
For example, `Option<NonZeroU32>`

is the same size as `u32`

:

```
use std::mem::size_of;
assert_eq!(size_of::<Option<core::num::NonZeroU32>>(), size_of::<u32>());
```

Run## Implementations

Creates a non-zero without checking whether the value is non-zero. This results in undefined behaviour if the value is zero.

##### Safety

The value must not be zero.

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

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::NonZeroU32::new(u32::MAX).unwrap();
assert_eq!(n.leading_zeros(), 0);
```

RunReturns 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::NonZeroU32::new(0b0101000).unwrap();
assert_eq!(n.trailing_zeros(), 3);
```

RunAdd an unsigned integer to a non-zero value.
Check for overflow and return `None`

on overflow
As a consequence, the result cannot wrap to zero.

##### Examples

```
#![feature(nonzero_ops)]
let one = NonZeroU32::new(1)?;
let two = NonZeroU32::new(2)?;
let max = NonZeroU32::new(u32::MAX)?;
assert_eq!(Some(two), one.checked_add(1));
assert_eq!(None, max.checked_add(1));
```

RunAdd an unsigned integer to a non-zero value,
assuming overflow cannot occur.
Overflow is unchecked, and it is undefined behaviour to overflow
*even if the result would wrap to a non-zero value*.
The behaviour is undefined as soon as
`self + rhs > u32::MAX`

.

##### Examples

```
#![feature(nonzero_ops)]
let one = NonZeroU32::new(1)?;
let two = NonZeroU32::new(2)?;
assert_eq!(two, unsafe { one.unchecked_add(1) });
```

RunReturns the smallest power of two greater than or equal to n.
Check for overflow and return `None`

if the next power of two is greater than the type’s maximum value.
As a consequence, the result cannot wrap to zero.

##### Examples

```
#![feature(nonzero_ops)]
let two = NonZeroU32::new(2)?;
let three = NonZeroU32::new(3)?;
let four = NonZeroU32::new(4)?;
let max = NonZeroU32::new(u32::MAX)?;
assert_eq!(Some(two), two.checked_next_power_of_two() );
assert_eq!(Some(four), three.checked_next_power_of_two() );
assert_eq!(None, max.checked_next_power_of_two() );
```

RunMultiply two non-zero integers together.
Check for overflow and return `None`

on overflow.
As a consequence, the result cannot wrap to zero.

##### Examples

```
#![feature(nonzero_ops)]
let two = NonZeroU32::new(2)?;
let four = NonZeroU32::new(4)?;
let max = NonZeroU32::new(u32::MAX)?;
assert_eq!(Some(four), two.checked_mul(two));
assert_eq!(None, max.checked_mul(two));
```

RunMultiply two non-zero integers together,
assuming overflow cannot occur.
Overflow is unchecked, and it is undefined behaviour to overflow
*even if the result would wrap to a non-zero value*.
The behaviour is undefined as soon as
`self * rhs > u32::MAX`

.

##### Examples

```
#![feature(nonzero_ops)]
let two = NonZeroU32::new(2)?;
let four = NonZeroU32::new(4)?;
assert_eq!(four, unsafe { two.unchecked_mul(two) });
```

RunRaise non-zero value to an integer power.
Check for overflow and return `None`

on overflow.
As a consequence, the result cannot wrap to zero.

##### Examples

```
#![feature(nonzero_ops)]
let three = NonZeroU32::new(3)?;
let twenty_seven = NonZeroU32::new(27)?;
let half_max = NonZeroU32::new(u32::MAX / 2)?;
assert_eq!(Some(twenty_seven), three.checked_pow(3));
assert_eq!(None, half_max.checked_pow(3));
```

RunRaise non-zero value to an integer power.
Return `u32::MAX`

on overflow.

##### Examples

```
#![feature(nonzero_ops)]
let three = NonZeroU32::new(3)?;
let twenty_seven = NonZeroU32::new(27)?;
let max = NonZeroU32::new(u32::MAX)?;
assert_eq!(twenty_seven, three.saturating_pow(3));
assert_eq!(max, max.saturating_pow(3));
```

RunReturns `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::NonZeroU32::new(8).unwrap();
assert!(eight.is_power_of_two());
let ten = std::num::NonZeroU32::new(10).unwrap();
assert!(!ten.is_power_of_two());
```

Run## Trait Implementations

#### type Output = NonZeroU32

#### type Output = NonZeroU32

The resulting type after applying the `|`

operator.

Performs the `|`

operation. Read more

#### type Output = NonZeroU32

#### type Output = NonZeroU32

The resulting type after applying the `|`

operator.

Performs the `|`

operation. Read more

#### type Output = NonZeroU32

#### type Output = NonZeroU32

The resulting type after applying the `|`

operator.

Performs the `|=`

operation. Read more

Performs the `|=`

operation. Read more

Converts `NonZeroU16`

to `NonZeroU32`

losslessly.

Converts `NonZeroU32`

to `NonZeroU128`

losslessly.

Converts a `NonZeroU32`

into an `u32`

Converts `NonZeroU32`

to `NonZeroU64`

losslessly.

Converts `NonZeroU32`

to `NonZeroI64`

losslessly.

Converts `NonZeroU32`

to `NonZeroI128`

losslessly.

Converts `NonZeroU8`

to `NonZeroU32`

losslessly.

#### type Err = ParseIntError

#### type Err = ParseIntError

The associated error which can be returned from parsing.

Parses a string `s`

to return a value of this type. Read more

This method tests for `self`

and `other`

values to be equal, and is used
by `==`

. Read more

This method tests for `!=`

.

This method returns an ordering between `self`

and `other`

values if one exists. Read more

This method tests less than (for `self`

and `other`

) and is used by the `<`

operator. Read more

This method tests less than or equal to (for `self`

and `other`

) and is used by the `<=`

operator. Read more

This method tests greater than (for `self`

and `other`

) and is used by the `>`

operator. Read more

#### pub fn try_from(

value: NonZeroI128

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroI128>>::Error>

#### pub fn try_from(

value: NonZeroI128

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroI128>>::Error>

Attempts to convert `NonZeroI128`

to `NonZeroU32`

.

#### type Error = TryFromIntError

#### type Error = TryFromIntError

The type returned in the event of a conversion error.

#### pub fn try_from(

value: NonZeroI16

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroI16>>::Error>

#### pub fn try_from(

value: NonZeroI16

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroI16>>::Error>

Attempts to convert `NonZeroI16`

to `NonZeroU32`

.

#### type Error = TryFromIntError

#### type Error = TryFromIntError

The type returned in the event of a conversion error.

#### pub fn try_from(

value: NonZeroI32

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroI32>>::Error>

#### pub fn try_from(

value: NonZeroI32

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroI32>>::Error>

Attempts to convert `NonZeroI32`

to `NonZeroU32`

.

#### type Error = TryFromIntError

#### type Error = TryFromIntError

The type returned in the event of a conversion error.

#### pub fn try_from(

value: NonZeroI64

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroI64>>::Error>

#### pub fn try_from(

value: NonZeroI64

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroI64>>::Error>

Attempts to convert `NonZeroI64`

to `NonZeroU32`

.

#### type Error = TryFromIntError

#### type Error = TryFromIntError

The type returned in the event of a conversion error.

#### pub fn try_from(

value: NonZeroI8

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroI8>>::Error>

#### pub fn try_from(

value: NonZeroI8

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroI8>>::Error>

Attempts to convert `NonZeroI8`

to `NonZeroU32`

.

#### type Error = TryFromIntError

#### type Error = TryFromIntError

The type returned in the event of a conversion error.

#### pub fn try_from(

value: NonZeroIsize

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroIsize>>::Error>

#### pub fn try_from(

value: NonZeroIsize

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroIsize>>::Error>

Attempts to convert `NonZeroIsize`

to `NonZeroU32`

.

#### type Error = TryFromIntError

#### type Error = TryFromIntError

The type returned in the event of a conversion error.

#### pub fn try_from(

value: NonZeroU128

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroU128>>::Error>

#### pub fn try_from(

value: NonZeroU128

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroU128>>::Error>

Attempts to convert `NonZeroU128`

to `NonZeroU32`

.

#### type Error = TryFromIntError

#### type Error = TryFromIntError

The type returned in the event of a conversion error.

#### pub fn try_from(

value: NonZeroU32

) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroU32>>::Error>

#### pub fn try_from(

value: NonZeroU32

) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroU32>>::Error>

Attempts to convert `NonZeroU32`

to `NonZeroU8`

.

#### type Error = TryFromIntError

#### type Error = TryFromIntError

The type returned in the event of a conversion error.

#### pub fn try_from(

value: NonZeroU32

) -> Result<NonZeroI32, <NonZeroI32 as TryFrom<NonZeroU32>>::Error>

#### pub fn try_from(

value: NonZeroU32

) -> Result<NonZeroI32, <NonZeroI32 as TryFrom<NonZeroU32>>::Error>

Attempts to convert `NonZeroU32`

to `NonZeroI32`

.

#### type Error = TryFromIntError

#### type Error = TryFromIntError

The type returned in the event of a conversion error.

#### pub fn try_from(

value: NonZeroU32

) -> Result<NonZeroI16, <NonZeroI16 as TryFrom<NonZeroU32>>::Error>

#### pub fn try_from(

value: NonZeroU32

) -> Result<NonZeroI16, <NonZeroI16 as TryFrom<NonZeroU32>>::Error>

Attempts to convert `NonZeroU32`

to `NonZeroI16`

.

#### type Error = TryFromIntError

#### type Error = TryFromIntError

The type returned in the event of a conversion error.

#### pub fn try_from(

value: NonZeroU32

) -> Result<NonZeroU16, <NonZeroU16 as TryFrom<NonZeroU32>>::Error>

#### pub fn try_from(

value: NonZeroU32

) -> Result<NonZeroU16, <NonZeroU16 as TryFrom<NonZeroU32>>::Error>

Attempts to convert `NonZeroU32`

to `NonZeroU16`

.

#### type Error = TryFromIntError

#### type Error = TryFromIntError

The type returned in the event of a conversion error.

#### pub fn try_from(

value: NonZeroU32

) -> Result<NonZeroIsize, <NonZeroIsize as TryFrom<NonZeroU32>>::Error>

#### pub fn try_from(

value: NonZeroU32

) -> Result<NonZeroIsize, <NonZeroIsize as TryFrom<NonZeroU32>>::Error>

Attempts to convert `NonZeroU32`

to `NonZeroIsize`

.

#### type Error = TryFromIntError

#### type Error = TryFromIntError

The type returned in the event of a conversion error.

#### pub fn try_from(

value: NonZeroU32

) -> Result<NonZeroI8, <NonZeroI8 as TryFrom<NonZeroU32>>::Error>

#### pub fn try_from(

value: NonZeroU32

) -> Result<NonZeroI8, <NonZeroI8 as TryFrom<NonZeroU32>>::Error>

Attempts to convert `NonZeroU32`

to `NonZeroI8`

.

#### type Error = TryFromIntError

#### 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>

#### pub fn try_from(

value: NonZeroU32

) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroU32>>::Error>

Attempts to convert `NonZeroU32`

to `NonZeroUsize`

.

#### type Error = TryFromIntError

#### type Error = TryFromIntError

The type returned in the event of a conversion error.

#### pub fn try_from(

value: NonZeroU64

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroU64>>::Error>

#### pub fn try_from(

value: NonZeroU64

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroU64>>::Error>

Attempts to convert `NonZeroU64`

to `NonZeroU32`

.

#### type Error = TryFromIntError

#### 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>

#### pub fn try_from(

value: NonZeroUsize

) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroUsize>>::Error>

Attempts to convert `NonZeroUsize`

to `NonZeroU32`

.

#### type Error = TryFromIntError

#### type Error = TryFromIntError

The type returned in the event of a conversion error.

Attempts to convert `u32`

to `NonZeroU32`

.

#### type Error = TryFromIntError

#### type Error = TryFromIntError

The type returned in the event of a conversion error.

## Auto Trait Implementations

### impl RefUnwindSafe for NonZeroU32

### impl Send for NonZeroU32

### impl Sync for NonZeroU32

### impl Unpin for NonZeroU32

### impl UnwindSafe for NonZeroU32

## Blanket Implementations

Mutably borrows from an owned value. Read more