#[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>());
RunImplementations
sourceimpl NonZeroU8
impl NonZeroU8
const: 1.28.0 · sourcepub const unsafe fn new_unchecked(n: u8) -> Self
pub const unsafe fn new_unchecked(n: u8) -> Self
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);
Run1.53.0 (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);
Runsourceimpl 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));
Runsourcepub 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) });
Runsourcepub 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() );
Runsourcepub 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);
Runsourcepub 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);
Runsourceimpl 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));
Runsourcepub 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) });
Runsourcepub 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));
Runsourcepub 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));
Runsourceimpl 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());
RunTrait Implementations
1.45.0 (const: unstable) · sourceimpl BitOrAssign<NonZeroU8> for NonZeroU8
impl BitOrAssign<NonZeroU8> for NonZeroU8
const: unstable · sourcefn bitor_assign(&mut self, rhs: Self)
fn bitor_assign(&mut self, rhs: Self)
Performs the |=
operation. Read more
1.45.0 (const: unstable) · sourceimpl BitOrAssign<u8> for NonZeroU8
impl BitOrAssign<u8> for NonZeroU8
const: unstable · sourcefn bitor_assign(&mut self, rhs: u8)
fn bitor_assign(&mut self, rhs: u8)
Performs the |=
operation. Read more
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroU16
impl From<NonZeroU8> for NonZeroU16
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroIsize
impl From<NonZeroU8> for NonZeroIsize
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroU32
impl From<NonZeroU8> for NonZeroU32
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroU64
impl From<NonZeroU8> for NonZeroU64
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroU128
impl From<NonZeroU8> for NonZeroU128
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroUsize
impl From<NonZeroU8> for NonZeroUsize
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroI16
impl From<NonZeroU8> for NonZeroI16
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroI32
impl From<NonZeroU8> for NonZeroI32
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroI64
impl From<NonZeroU8> for NonZeroI64
1.41.0 (const: unstable) · sourceimpl From<NonZeroU8> for NonZeroI128
impl From<NonZeroU8> for NonZeroI128
sourceimpl Ord for NonZeroU8
impl Ord for NonZeroU8
1.21.0 · sourcefn max(self, other: Self) -> Self where
Self: Sized,
fn max(self, other: Self) -> Self where
Self: Sized,
Compares and returns the maximum of two values. Read more
sourceimpl PartialOrd<NonZeroU8> for NonZeroU8
impl PartialOrd<NonZeroU8> for NonZeroU8
sourcefn partial_cmp(&self, other: &NonZeroU8) -> Option<Ordering>
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
sourcefn try_from(value: NonZeroI128) -> Result<Self, Self::Error>
fn try_from(value: NonZeroI128) -> Result<Self, Self::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
sourcefn try_from(value: NonZeroI16) -> Result<Self, Self::Error>
fn try_from(value: NonZeroI16) -> Result<Self, Self::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
sourcefn try_from(value: NonZeroI32) -> Result<Self, Self::Error>
fn try_from(value: NonZeroI32) -> Result<Self, Self::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
sourcefn try_from(value: NonZeroI64) -> Result<Self, Self::Error>
fn try_from(value: NonZeroI64) -> Result<Self, Self::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
sourcefn try_from(value: NonZeroIsize) -> Result<Self, Self::Error>
fn try_from(value: NonZeroIsize) -> Result<Self, Self::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
sourcefn try_from(value: NonZeroU128) -> Result<Self, Self::Error>
fn try_from(value: NonZeroU128) -> Result<Self, Self::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
sourcefn try_from(value: NonZeroU16) -> Result<Self, Self::Error>
fn try_from(value: NonZeroU16) -> Result<Self, Self::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
sourcefn try_from(value: NonZeroU32) -> Result<Self, Self::Error>
fn try_from(value: NonZeroU32) -> Result<Self, Self::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
sourcefn try_from(value: NonZeroU64) -> Result<Self, Self::Error>
fn try_from(value: NonZeroU64) -> Result<Self, Self::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
sourcefn try_from(value: NonZeroUsize) -> Result<Self, Self::Error>
fn try_from(value: NonZeroUsize) -> Result<Self, Self::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 · sourcefn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Mutably borrows from an owned value. Read more