# Struct std::num::NonZeroU8 1.28.0[−][src]

#[repr(transparent)]pub struct NonZeroU8(_);

## Expand description

An integer that is known not to equal zero.

This enables some memory layout optimization.
For example, `Option<NonZeroU8>`

is the same size as `u8`

:

use std::mem::size_of; assert_eq!(size_of::<Option<core::num::NonZeroU8>>(), size_of::<u8>());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::NonZeroU8::new(u8::MAX).unwrap(); assert_eq!(n.leading_zeros(), 0);Run

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::NonZeroU8::new(0b0101000).unwrap(); assert_eq!(n.trailing_zeros(), 3);Run

Add 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 = NonZeroU8::new(1)?; let two = NonZeroU8::new(2)?; let max = NonZeroU8::new(u8::MAX)?; assert_eq!(Some(two), one.checked_add(1)); assert_eq!(None, max.checked_add(1));Run

Add 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 > u8::MAX`

.

# Examples

#![feature(nonzero_ops)] let one = NonZeroU8::new(1)?; let two = NonZeroU8::new(2)?; assert_eq!(two, unsafe { one.unchecked_add(1) });Run

Returns 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 = NonZeroU8::new(2)?; let three = NonZeroU8::new(3)?; let four = NonZeroU8::new(4)?; let max = NonZeroU8::new(u8::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() );Run

Multiply 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 = NonZeroU8::new(2)?; let four = NonZeroU8::new(4)?; let max = NonZeroU8::new(u8::MAX)?; assert_eq!(Some(four), two.checked_mul(two)); assert_eq!(None, max.checked_mul(two));Run

Multiply 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 > u8::MAX`

.

# Examples

#![feature(nonzero_ops)] let two = NonZeroU8::new(2)?; let four = NonZeroU8::new(4)?; assert_eq!(four, unsafe { two.unchecked_mul(two) });Run

Raise 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 = NonZeroU8::new(3)?; let twenty_seven = NonZeroU8::new(27)?; let half_max = NonZeroU8::new(u8::MAX / 2)?; assert_eq!(Some(twenty_seven), three.checked_pow(3)); assert_eq!(None, half_max.checked_pow(3));Run

Raise non-zero value to an integer power.
Return `u8::MAX`

on overflow.

# Examples

#![feature(nonzero_ops)] let three = NonZeroU8::new(3)?; let twenty_seven = NonZeroU8::new(27)?; let max = NonZeroU8::new(u8::MAX)?; assert_eq!(twenty_seven, three.saturating_pow(3)); assert_eq!(max, max.saturating_pow(3));Run

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::NonZeroU8::new(8).unwrap(); assert!(eight.is_power_of_two()); let ten = std::num::NonZeroU8::new(10).unwrap(); assert!(!ten.is_power_of_two());Run

## Trait Implementations

Performs the `|=`

operation. Read more

Performs the `|=`

operation. Read more

Converts `NonZeroU8`

to `NonZeroUsize`

losslessly.

Converts `NonZeroU8`

to `NonZeroI128`

losslessly.

Converts `NonZeroU8`

to `NonZeroU32`

losslessly.

Converts `NonZeroU8`

to `NonZeroI64`

losslessly.

Converts `NonZeroU8`

to `NonZeroI16`

losslessly.

Converts `NonZeroU8`

to `NonZeroI32`

losslessly.

Converts `NonZeroU8`

to `NonZeroU64`

losslessly.

Converts `NonZeroU8`

to `NonZeroU16`

losslessly.

Converts `NonZeroU8`

to `NonZeroU128`

losslessly.

Converts `NonZeroU8`

to `NonZeroIsize`

losslessly.

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<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroI128>>::Error>

[src]

`pub fn try_from(`

value: NonZeroI128

) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroI128>>::Error>

[src]Attempts to convert `NonZeroI128`

to `NonZeroU8`

.

`type Error = TryFromIntError`

`type Error = TryFromIntError`

The type returned in the event of a conversion error.

`pub fn try_from(`

value: NonZeroI16

) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroI16>>::Error>

[src]

`pub fn try_from(`

value: NonZeroI16

) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroI16>>::Error>

[src]Attempts to convert `NonZeroI16`

to `NonZeroU8`

.

`type Error = TryFromIntError`

`type Error = TryFromIntError`

The type returned in the event of a conversion error.

`pub fn try_from(`

value: NonZeroI32

) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroI32>>::Error>

[src]

`pub fn try_from(`

value: NonZeroI32

) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroI32>>::Error>

[src]Attempts to convert `NonZeroI32`

to `NonZeroU8`

.

`type Error = TryFromIntError`

`type Error = TryFromIntError`

The type returned in the event of a conversion error.

`pub fn try_from(`

value: NonZeroI64

) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroI64>>::Error>

[src]

`pub fn try_from(`

value: NonZeroI64

) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroI64>>::Error>

[src]Attempts to convert `NonZeroI64`

to `NonZeroU8`

.

`type Error = TryFromIntError`

`type Error = TryFromIntError`

The type returned in the event of a conversion error.

`pub fn try_from(`

value: NonZeroIsize

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

[src]

`pub fn try_from(`

value: NonZeroIsize

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

[src]Attempts to convert `NonZeroIsize`

to `NonZeroU8`

.

`type Error = TryFromIntError`

`type Error = TryFromIntError`

The type returned in the event of a conversion error.

`pub fn try_from(`

value: NonZeroU128

) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroU128>>::Error>

[src]

`pub fn try_from(`

value: NonZeroU128

) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroU128>>::Error>

[src]Attempts to convert `NonZeroU128`

to `NonZeroU8`

.

`type Error = TryFromIntError`

`type Error = TryFromIntError`

The type returned in the event of a conversion error.

`pub fn try_from(`

value: NonZeroU16

) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroU16>>::Error>

[src]

`pub fn try_from(`

value: NonZeroU16

) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroU16>>::Error>

[src]Attempts to convert `NonZeroU16`

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<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroU32>>::Error>

[src]

`pub fn try_from(`

value: NonZeroU32

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

[src]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: NonZeroU64

) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroU64>>::Error>

[src]

`pub fn try_from(`

value: NonZeroU64

) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroU64>>::Error>

[src]Attempts to convert `NonZeroU64`

to `NonZeroU8`

.

`type Error = TryFromIntError`

`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>

[src]

`pub fn try_from(`

value: NonZeroUsize

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

[src]Attempts to convert `NonZeroUsize`

to `NonZeroU8`

.

`type Error = TryFromIntError`

`type Error = TryFromIntError`

The type returned in the event of a conversion error.

## Auto Trait Implementations

`impl RefUnwindSafe for NonZeroU8`

`impl UnwindSafe for NonZeroU8`

## Blanket Implementations

Mutably borrows from an owned value. Read more