#[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>());Implementations
sourceimpl NonZeroU8
 
impl NonZeroU8
const: 1.28.0 · sourcepub const unsafe fn new_unchecked(n: u8) -> NonZeroU8
 
pub const unsafe fn new_unchecked(n: u8) -> NonZeroU8
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.
sourceimpl NonZeroU8
 
impl NonZeroU8
1.53.0 (const: 1.53.0) · sourcepub const fn leading_zeros(self) -> u32
 
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::NonZeroU8::new(u8::MAX).unwrap();
assert_eq!(n.leading_zeros(), 0);1.53.0 (const: 1.53.0) · sourcepub const fn trailing_zeros(self) -> u32
 
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::NonZeroU8::new(0b0101000).unwrap();
assert_eq!(n.trailing_zeros(), 3);sourceimpl NonZeroU8
 
impl NonZeroU8
sourcepub const fn checked_add(self, other: u8) -> Option<NonZeroU8>
 
pub const fn checked_add(self, other: u8) -> Option<NonZeroU8>
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));sourcepub const fn saturating_add(self, other: u8) -> NonZeroU8
 
pub const fn saturating_add(self, other: u8) -> NonZeroU8
sourcepub const unsafe fn unchecked_add(self, other: u8) -> NonZeroU8
 
pub const unsafe fn unchecked_add(self, other: u8) -> NonZeroU8
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) });sourcepub const fn checked_next_power_of_two(self) -> Option<NonZeroU8>
 
pub const fn checked_next_power_of_two(self) -> Option<NonZeroU8>
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() );sourcepub const fn log2(self) -> u32
 
pub const fn log2(self) -> u32
Returns the base 2 logarithm of the number, rounded down.
This is the same operation as
u8::log2,
except that it has no failure cases to worry about
since this value can never be zero.
Examples
#![feature(int_log)]
assert_eq!(NonZeroU8::new(7).unwrap().log2(), 2);
assert_eq!(NonZeroU8::new(8).unwrap().log2(), 3);
assert_eq!(NonZeroU8::new(9).unwrap().log2(), 3);sourcepub const fn log10(self) -> u32
 
pub const fn log10(self) -> u32
Returns the base 10 logarithm of the number, rounded down.
This is the same operation as
u8::log10,
except that it has no failure cases to worry about
since this value can never be zero.
Examples
#![feature(int_log)]
assert_eq!(NonZeroU8::new(99).unwrap().log10(), 1);
assert_eq!(NonZeroU8::new(100).unwrap().log10(), 2);
assert_eq!(NonZeroU8::new(101).unwrap().log10(), 2);sourceimpl NonZeroU8
 
impl NonZeroU8
sourcepub const fn checked_mul(self, other: NonZeroU8) -> Option<NonZeroU8>
 
pub const fn checked_mul(self, other: NonZeroU8) -> Option<NonZeroU8>
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));sourcepub const fn saturating_mul(self, other: NonZeroU8) -> NonZeroU8
 
pub const fn saturating_mul(self, other: NonZeroU8) -> NonZeroU8
sourcepub const unsafe fn unchecked_mul(self, other: NonZeroU8) -> NonZeroU8
 
pub const unsafe fn unchecked_mul(self, other: NonZeroU8) -> NonZeroU8
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) });sourcepub const fn checked_pow(self, other: u32) -> Option<NonZeroU8>
 
pub const fn checked_pow(self, other: u32) -> Option<NonZeroU8>
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));sourcepub const fn saturating_pow(self, other: u32) -> NonZeroU8
 
pub const fn saturating_pow(self, other: u32) -> NonZeroU8
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));sourceimpl NonZeroU8
 
impl NonZeroU8
1.59.0 (const: 1.59.0) · sourcepub const fn is_power_of_two(self) -> bool
 
pub const fn is_power_of_two(self) -> bool
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:
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());Trait Implementations
1.45.0 (const: unstable) · sourceimpl BitOrAssign<NonZeroU8> for NonZeroU8
 
impl BitOrAssign<NonZeroU8> for NonZeroU8
const: unstable · sourcepub fn bitor_assign(&mut self, rhs: NonZeroU8)
 
pub fn bitor_assign(&mut self, rhs: NonZeroU8)
Performs the |= operation. Read more
1.45.0 (const: unstable) · sourceimpl BitOrAssign<u8> for NonZeroU8
 
impl BitOrAssign<u8> for NonZeroU8
const: unstable · sourcepub fn bitor_assign(&mut self, rhs: u8)
 
pub fn bitor_assign(&mut self, rhs: u8)
Performs the |= operation. Read more
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroI64
 
impl From<NonZeroU8> for NonZeroI64
const: unstable · sourcepub fn from(small: NonZeroU8) -> NonZeroI64
 
pub fn from(small: NonZeroU8) -> NonZeroI64
Converts NonZeroU8 to NonZeroI64 losslessly.
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroIsize
 
impl From<NonZeroU8> for NonZeroIsize
const: unstable · sourcepub fn from(small: NonZeroU8) -> NonZeroIsize
 
pub fn from(small: NonZeroU8) -> NonZeroIsize
Converts NonZeroU8 to NonZeroIsize losslessly.
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroI16
 
impl From<NonZeroU8> for NonZeroI16
const: unstable · sourcepub fn from(small: NonZeroU8) -> NonZeroI16
 
pub fn from(small: NonZeroU8) -> NonZeroI16
Converts NonZeroU8 to NonZeroI16 losslessly.
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroUsize
 
impl From<NonZeroU8> for NonZeroUsize
const: unstable · sourcepub fn from(small: NonZeroU8) -> NonZeroUsize
 
pub fn from(small: NonZeroU8) -> NonZeroUsize
Converts NonZeroU8 to NonZeroUsize losslessly.
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroU16
 
impl From<NonZeroU8> for NonZeroU16
const: unstable · sourcepub fn from(small: NonZeroU8) -> NonZeroU16
 
pub fn from(small: NonZeroU8) -> NonZeroU16
Converts NonZeroU8 to NonZeroU16 losslessly.
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroI128
 
impl From<NonZeroU8> for NonZeroI128
const: unstable · sourcepub fn from(small: NonZeroU8) -> NonZeroI128
 
pub fn from(small: NonZeroU8) -> NonZeroI128
Converts NonZeroU8 to NonZeroI128 losslessly.
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroU64
 
impl From<NonZeroU8> for NonZeroU64
const: unstable · sourcepub fn from(small: NonZeroU8) -> NonZeroU64
 
pub fn from(small: NonZeroU8) -> NonZeroU64
Converts NonZeroU8 to NonZeroU64 losslessly.
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroU128
 
impl From<NonZeroU8> for NonZeroU128
const: unstable · sourcepub fn from(small: NonZeroU8) -> NonZeroU128
 
pub fn from(small: NonZeroU8) -> NonZeroU128
Converts NonZeroU8 to NonZeroU128 losslessly.
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroU32
 
impl From<NonZeroU8> for NonZeroU32
const: unstable · sourcepub fn from(small: NonZeroU8) -> NonZeroU32
 
pub fn from(small: NonZeroU8) -> NonZeroU32
Converts NonZeroU8 to NonZeroU32 losslessly.
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroI32
 
impl From<NonZeroU8> for NonZeroI32
const: unstable · sourcepub fn from(small: NonZeroU8) -> NonZeroI32
 
pub fn from(small: NonZeroU8) -> NonZeroI32
Converts NonZeroU8 to NonZeroI32 losslessly.
sourceimpl Ord for NonZeroU8
 
impl Ord for NonZeroU8
sourceimpl PartialOrd<NonZeroU8> for NonZeroU8
 
impl PartialOrd<NonZeroU8> for NonZeroU8
sourcepub fn partial_cmp(&self, other: &NonZeroU8) -> Option<Ordering>
 
pub fn partial_cmp(&self, other: &NonZeroU8) -> Option<Ordering>
This method returns an ordering between self and other values if one exists. Read more
1.0.0 · sourcefn lt(&self, other: &Rhs) -> bool
 
fn lt(&self, other: &Rhs) -> bool
This method tests less than (for self and other) and is used by the < operator. Read more
1.0.0 · sourcefn le(&self, other: &Rhs) -> bool
 
fn le(&self, other: &Rhs) -> bool
This method tests less than or equal to (for self and other) and is used by the <=
operator. Read more
1.49.0 · sourceimpl TryFrom<NonZeroI128> for NonZeroU8
 
impl TryFrom<NonZeroI128> for NonZeroU8
sourcepub fn try_from(
    value: NonZeroI128
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroI128>>::Error>
 
pub fn try_from(
    value: NonZeroI128
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroI128>>::Error>
Attempts to convert NonZeroI128 to NonZeroU8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
1.49.0 · sourceimpl TryFrom<NonZeroI16> for NonZeroU8
 
impl TryFrom<NonZeroI16> for NonZeroU8
sourcepub fn try_from(
    value: NonZeroI16
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroI16>>::Error>
 
pub fn try_from(
    value: NonZeroI16
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroI16>>::Error>
Attempts to convert NonZeroI16 to NonZeroU8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
1.49.0 · sourceimpl TryFrom<NonZeroI32> for NonZeroU8
 
impl TryFrom<NonZeroI32> for NonZeroU8
sourcepub fn try_from(
    value: NonZeroI32
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroI32>>::Error>
 
pub fn try_from(
    value: NonZeroI32
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroI32>>::Error>
Attempts to convert NonZeroI32 to NonZeroU8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
1.49.0 · sourceimpl TryFrom<NonZeroI64> for NonZeroU8
 
impl TryFrom<NonZeroI64> for NonZeroU8
sourcepub fn try_from(
    value: NonZeroI64
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroI64>>::Error>
 
pub fn try_from(
    value: NonZeroI64
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroI64>>::Error>
Attempts to convert NonZeroI64 to NonZeroU8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
1.49.0 · sourceimpl TryFrom<NonZeroIsize> for NonZeroU8
 
impl TryFrom<NonZeroIsize> for NonZeroU8
sourcepub fn try_from(
    value: NonZeroIsize
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroIsize>>::Error>
 
pub fn try_from(
    value: NonZeroIsize
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroIsize>>::Error>
Attempts to convert NonZeroIsize to NonZeroU8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
1.49.0 · sourceimpl TryFrom<NonZeroU128> for NonZeroU8
 
impl TryFrom<NonZeroU128> for NonZeroU8
sourcepub fn try_from(
    value: NonZeroU128
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroU128>>::Error>
 
pub fn try_from(
    value: NonZeroU128
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroU128>>::Error>
Attempts to convert NonZeroU128 to NonZeroU8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
1.49.0 · sourceimpl TryFrom<NonZeroU16> for NonZeroU8
 
impl TryFrom<NonZeroU16> for NonZeroU8
sourcepub fn try_from(
    value: NonZeroU16
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroU16>>::Error>
 
pub fn try_from(
    value: NonZeroU16
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroU16>>::Error>
Attempts to convert NonZeroU16 to NonZeroU8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
1.49.0 · sourceimpl TryFrom<NonZeroU32> for NonZeroU8
 
impl TryFrom<NonZeroU32> for NonZeroU8
sourcepub 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.
1.49.0 · sourceimpl TryFrom<NonZeroU64> for NonZeroU8
 
impl TryFrom<NonZeroU64> for NonZeroU8
sourcepub fn try_from(
    value: NonZeroU64
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroU64>>::Error>
 
pub fn try_from(
    value: NonZeroU64
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroU64>>::Error>
Attempts to convert NonZeroU64 to NonZeroU8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
1.49.0 · sourceimpl TryFrom<NonZeroUsize> for NonZeroU8
 
impl TryFrom<NonZeroUsize> for NonZeroU8
sourcepub fn try_from(
    value: NonZeroUsize
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroUsize>>::Error>
 
pub fn try_from(
    value: NonZeroUsize
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroUsize>>::Error>
Attempts to convert NonZeroUsize to NonZeroU8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
impl Copy for NonZeroU8
impl Eq for NonZeroU8
impl StructuralEq for NonZeroU8
impl StructuralPartialEq for NonZeroU8
Auto Trait Implementations
impl RefUnwindSafe for NonZeroU8
impl Send for NonZeroU8
impl Sync for NonZeroU8
impl Unpin for NonZeroU8
impl UnwindSafe for NonZeroU8
Blanket Implementations
sourceimpl<T> BorrowMut<T> for T where
    T: ?Sized, 
 
impl<T> BorrowMut<T> for T where
    T: ?Sized, 
const: unstable · sourcepub fn borrow_mut(&mut self) -> &mut T
 
pub fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more