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Struct std::num::NonZeroU64
pub struct NonZeroU64(/* private fields */);
An integer that is known not to equal zero.
This enables some memory layout optimization. For example, Option<NonZeroU64>
is the same size as u64
:
use std::mem::size_of;
assert_eq!(size_of::<Option<core::num::NonZeroU64>>(), size_of::<u64>());
Layout
NonZeroU64
is guaranteed to have the same layout and bit validity as u64
with the exception that 0
is not a valid instance. Option<NonZeroU64>
is guaranteed to be compatible with u64
, including in FFI.
Thanks to the null pointer optimization, NonZeroU64
and Option<NonZeroU64>
are guaranteed to have the same size and alignment:
use std::num::NonZeroU64;
assert_eq!(size_of::<NonZeroU64>(), size_of::<Option<NonZeroU64>>());
assert_eq!(align_of::<NonZeroU64>(), align_of::<Option<NonZeroU64>>());
Implementations
impl NonZeroU64
pub const unsafe fn new_unchecked(n: u64) -> NonZeroU64
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.
pub const fn new(n: u64) -> Option<NonZeroU64>
Creates a non-zero if the given value is not zero.
pub const fn get(self) -> u64
Returns the value as a primitive type.
impl NonZeroU64
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::NonZeroU64::new(u64::MAX).unwrap();
assert_eq!(n.leading_zeros(), 0);
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::NonZeroU64::new(0b0101000).unwrap();
assert_eq!(n.trailing_zeros(), 3);
impl NonZeroU64
pub const fn checked_add(self, other: u64) -> Option<NonZeroU64>
Adds an unsigned integer to a non-zero value. Checks for overflow and returns None
on overflow. As a consequence, the result cannot wrap to zero.
Examples
let one = NonZeroU64::new(1)?;
let two = NonZeroU64::new(2)?;
let max = NonZeroU64::new(u64::MAX)?;
assert_eq!(Some(two), one.checked_add(1));
assert_eq!(None, max.checked_add(1));
pub const fn saturating_add(self, other: u64) -> NonZeroU64
Adds an unsigned integer to a non-zero value. Return NonZeroU64::MAX
on overflow.
Examples
let one = NonZeroU64::new(1)?;
let two = NonZeroU64::new(2)?;
let max = NonZeroU64::new(u64::MAX)?;
assert_eq!(two, one.saturating_add(1));
assert_eq!(max, max.saturating_add(1));
pub const unsafe fn unchecked_add(self, other: u64) -> NonZeroU64
nonzero_ops
#84186)
Adds 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 > u64::MAX
.
Examples
#![feature(nonzero_ops)]
let one = NonZeroU64::new(1)?;
let two = NonZeroU64::new(2)?;
assert_eq!(two, unsafe { one.unchecked_add(1) });
pub const fn checked_next_power_of_two(self) -> Option<NonZeroU64>
Returns the smallest power of two greater than or equal to n. Checks for overflow and returns 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
let two = NonZeroU64::new(2)?;
let three = NonZeroU64::new(3)?;
let four = NonZeroU64::new(4)?;
let max = NonZeroU64::new(u64::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() );
pub const fn ilog2(self) -> u32
Returns the base 2 logarithm of the number, rounded down.
This is the same operation as u64::ilog2
, except that it has no failure cases to worry about since this value can never be zero.
Examples
assert_eq!(NonZeroU64::new(7).unwrap().ilog2(), 2);
assert_eq!(NonZeroU64::new(8).unwrap().ilog2(), 3);
assert_eq!(NonZeroU64::new(9).unwrap().ilog2(), 3);
pub const fn ilog10(self) -> u32
Returns the base 10 logarithm of the number, rounded down.
This is the same operation as u64::ilog10
, except that it has no failure cases to worry about since this value can never be zero.
Examples
assert_eq!(NonZeroU64::new(99).unwrap().ilog10(), 1);
assert_eq!(NonZeroU64::new(100).unwrap().ilog10(), 2);
assert_eq!(NonZeroU64::new(101).unwrap().ilog10(), 2);
pub fn midpoint(self, rhs: NonZeroU64) -> NonZeroU64
num_midpoint
#110840)
Calculates the middle point of self
and rhs
.
midpoint(a, b)
is (a + b) >> 1
as if it were performed in a sufficiently-large signed integral type. This implies that the result is always rounded towards negative infinity and that no overflow will ever occur.
Examples
#![feature(num_midpoint)]
let one = NonZeroU64::new(1)?;
let two = NonZeroU64::new(2)?;
let four = NonZeroU64::new(4)?;
assert_eq!(one.midpoint(four), two);
assert_eq!(four.midpoint(one), two);
impl NonZeroU64
pub const fn checked_mul(self, other: NonZeroU64) -> Option<NonZeroU64>
Multiplies two non-zero integers together. Checks for overflow and returns None
on overflow. As a consequence, the result cannot wrap to zero.
Examples
let two = NonZeroU64::new(2)?;
let four = NonZeroU64::new(4)?;
let max = NonZeroU64::new(u64::MAX)?;
assert_eq!(Some(four), two.checked_mul(two));
assert_eq!(None, max.checked_mul(two));
pub const fn saturating_mul(self, other: NonZeroU64) -> NonZeroU64
Multiplies two non-zero integers together. Return NonZeroU64::MAX
on overflow.
Examples
let two = NonZeroU64::new(2)?;
let four = NonZeroU64::new(4)?;
let max = NonZeroU64::new(u64::MAX)?;
assert_eq!(four, two.saturating_mul(two));
assert_eq!(max, four.saturating_mul(max));
pub const unsafe fn unchecked_mul(self, other: NonZeroU64) -> NonZeroU64
nonzero_ops
#84186)
Multiplies 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 > u64::MAX
.
Examples
#![feature(nonzero_ops)]
let two = NonZeroU64::new(2)?;
let four = NonZeroU64::new(4)?;
assert_eq!(four, unsafe { two.unchecked_mul(two) });
pub const fn checked_pow(self, other: u32) -> Option<NonZeroU64>
Raises non-zero value to an integer power. Checks for overflow and returns None
on overflow. As a consequence, the result cannot wrap to zero.
Examples
let three = NonZeroU64::new(3)?;
let twenty_seven = NonZeroU64::new(27)?;
let half_max = NonZeroU64::new(u64::MAX / 2)?;
assert_eq!(Some(twenty_seven), three.checked_pow(3));
assert_eq!(None, half_max.checked_pow(3));
pub const fn saturating_pow(self, other: u32) -> NonZeroU64
Raise non-zero value to an integer power. Return NonZeroU64::MAX
on overflow.
Examples
let three = NonZeroU64::new(3)?;
let twenty_seven = NonZeroU64::new(27)?;
let max = NonZeroU64::new(u64::MAX)?;
assert_eq!(twenty_seven, three.saturating_pow(3));
assert_eq!(max, max.saturating_pow(3));
impl NonZeroU64
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::NonZeroU64::new(8).unwrap();
assert!(eight.is_power_of_two());
let ten = std::num::NonZeroU64::new(10).unwrap();
assert!(!ten.is_power_of_two());
impl NonZeroU64
pub const MIN: NonZeroU64 = _
The smallest value that can be represented by this non-zero integer type, 1.
Examples
assert_eq!(NonZeroU64::MIN.get(), 1u64);
pub const MAX: NonZeroU64 = _
The largest value that can be represented by this non-zero integer type, equal to u64::MAX
.
Examples
assert_eq!(NonZeroU64::MAX.get(), u64::MAX);
impl NonZeroU64
Trait Implementations
impl Binary for NonZeroU64
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>
impl BitOr<NonZeroU64> for u64
type Output = NonZeroU64
|
operator.
fn bitor(self, rhs: NonZeroU64) -> <u64 as BitOr<NonZeroU64>>::Output
|
operation. Read more
impl BitOr<u64> for NonZeroU64
type Output = NonZeroU64
|
operator.
fn bitor(self, rhs: u64) -> <NonZeroU64 as BitOr<u64>>::Output
|
operation. Read more
impl BitOr for NonZeroU64
type Output = NonZeroU64
|
operator.
fn bitor(self, rhs: NonZeroU64) -> <NonZeroU64 as BitOr>::Output
|
operation. Read more
impl BitOrAssign<u64> for NonZeroU64
impl BitOrAssign for NonZeroU64
impl Clone for NonZeroU64
fn clone(&self) -> NonZeroU64
fn clone_from(&mut self, source: &Self)
source
. Read more
impl Debug for NonZeroU64
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>
impl Display for NonZeroU64
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>
impl Div<NonZeroU64> for u64
fn div(self, other: NonZeroU64) -> u64
This operation rounds towards zero, truncating any fractional part of the exact result, and cannot panic.
type Output = u64
/
operator.
impl From<NonZeroU16> for NonZeroU64
fn from(small: NonZeroU16) -> NonZeroU64
Converts NonZeroU16
to NonZeroU64
losslessly.
impl From<NonZeroU32> for NonZeroU64
fn from(small: NonZeroU32) -> NonZeroU64
Converts NonZeroU32
to NonZeroU64
losslessly.
impl From<NonZeroU64> for NonZeroI128
fn from(small: NonZeroU64) -> NonZeroI128
Converts NonZeroU64
to NonZeroI128
losslessly.
impl From<NonZeroU64> for NonZeroU128
fn from(small: NonZeroU64) -> NonZeroU128
Converts NonZeroU64
to NonZeroU128
losslessly.
impl From<NonZeroU64> for u64
fn from(nonzero: NonZeroU64) -> u64
Converts a NonZeroU64
into an u64
impl From<NonZeroU8> for NonZeroU64
fn from(small: NonZeroU8) -> NonZeroU64
Converts NonZeroU8
to NonZeroU64
losslessly.
impl FromStr for NonZeroU64
type Err = ParseIntError
fn from_str(src: &str) -> Result<NonZeroU64, <NonZeroU64 as FromStr>::Err>
s
to return a value of this type. Read more
impl Hash for NonZeroU64
fn hash<__H>(&self, state: &mut __H)
where
__H: Hasher,
fn hash_slice<H>(data: &[Self], state: &mut H)
where
H: Hasher,
Self: Sized,
impl LowerHex for NonZeroU64
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>
impl Octal for NonZeroU64
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>
impl Ord for NonZeroU64
fn cmp(&self, other: &NonZeroU64) -> Ordering
fn max(self, other: Self) -> Self
where
Self: Sized,
fn min(self, other: Self) -> Self
where
Self: Sized,
fn clamp(self, min: Self, max: Self) -> Self
where
Self: Sized + PartialOrd,
impl PartialEq for NonZeroU64
fn eq(&self, other: &NonZeroU64) -> bool
self
and other
values to be equal, and is used by ==
.
fn ne(&self, other: &Rhs) -> bool
!=
. The default implementation is almost always sufficient, and should not be overridden without very good reason.
impl PartialOrd for NonZeroU64
fn partial_cmp(&self, other: &NonZeroU64) -> Option<Ordering>
fn lt(&self, other: &Rhs) -> bool
fn le(&self, other: &Rhs) -> bool
self
and other
) and is used by the <=
operator. Read more
fn gt(&self, other: &Rhs) -> bool
fn ge(&self, other: &Rhs) -> bool
self
and other
) and is used by the >=
operator. Read more
impl Rem<NonZeroU64> for u64
fn rem(self, other: NonZeroU64) -> u64
This operation satisfies n % d == n - (n / d) * d
, and cannot panic.
type Output = u64
%
operator.
impl TryFrom<NonZeroI128> for NonZeroU64
fn try_from(
value: NonZeroI128
) -> Result<NonZeroU64, <NonZeroU64 as TryFrom<NonZeroI128>>::Error>
Attempts to convert NonZeroI128
to NonZeroU64
.
type Error = TryFromIntError
impl TryFrom<NonZeroI16> for NonZeroU64
fn try_from(
value: NonZeroI16
) -> Result<NonZeroU64, <NonZeroU64 as TryFrom<NonZeroI16>>::Error>
Attempts to convert NonZeroI16
to NonZeroU64
.
type Error = TryFromIntError
impl TryFrom<NonZeroI32> for NonZeroU64
fn try_from(
value: NonZeroI32
) -> Result<NonZeroU64, <NonZeroU64 as TryFrom<NonZeroI32>>::Error>
Attempts to convert NonZeroI32
to NonZeroU64
.
type Error = TryFromIntError
impl TryFrom<NonZeroI64> for NonZeroU64
fn try_from(
value: NonZeroI64
) -> Result<NonZeroU64, <NonZeroU64 as TryFrom<NonZeroI64>>::Error>
Attempts to convert NonZeroI64
to NonZeroU64
.
type Error = TryFromIntError
impl TryFrom<NonZeroI8> for NonZeroU64
fn try_from(
value: NonZeroI8
) -> Result<NonZeroU64, <NonZeroU64 as TryFrom<NonZeroI8>>::Error>
Attempts to convert NonZeroI8
to NonZeroU64
.
type Error = TryFromIntError
impl TryFrom<NonZeroIsize> for NonZeroU64
fn try_from(
value: NonZeroIsize
) -> Result<NonZeroU64, <NonZeroU64 as TryFrom<NonZeroIsize>>::Error>
Attempts to convert NonZeroIsize
to NonZeroU64
.
type Error = TryFromIntError
impl TryFrom<NonZeroU128> for NonZeroU64
fn try_from(
value: NonZeroU128
) -> Result<NonZeroU64, <NonZeroU64 as TryFrom<NonZeroU128>>::Error>
Attempts to convert NonZeroU128
to NonZeroU64
.
type Error = TryFromIntError
impl TryFrom<NonZeroU64> for NonZeroI16
fn try_from(
value: NonZeroU64
) -> Result<NonZeroI16, <NonZeroI16 as TryFrom<NonZeroU64>>::Error>
Attempts to convert NonZeroU64
to NonZeroI16
.
type Error = TryFromIntError
impl TryFrom<NonZeroU64> for NonZeroI32
fn try_from(
value: NonZeroU64
) -> Result<NonZeroI32, <NonZeroI32 as TryFrom<NonZeroU64>>::Error>
Attempts to convert NonZeroU64
to NonZeroI32
.
type Error = TryFromIntError
impl TryFrom<NonZeroU64> for NonZeroI64
fn try_from(
value: NonZeroU64
) -> Result<NonZeroI64, <NonZeroI64 as TryFrom<NonZeroU64>>::Error>
Attempts to convert NonZeroU64
to NonZeroI64
.
type Error = TryFromIntError
impl TryFrom<NonZeroU64> for NonZeroI8
fn try_from(
value: NonZeroU64
) -> Result<NonZeroI8, <NonZeroI8 as TryFrom<NonZeroU64>>::Error>
Attempts to convert NonZeroU64
to NonZeroI8
.
type Error = TryFromIntError
impl TryFrom<NonZeroU64> for NonZeroIsize
fn try_from(
value: NonZeroU64
) -> Result<NonZeroIsize, <NonZeroIsize as TryFrom<NonZeroU64>>::Error>
Attempts to convert NonZeroU64
to NonZeroIsize
.
type Error = TryFromIntError
impl TryFrom<NonZeroU64> for NonZeroU16
fn try_from(
value: NonZeroU64
) -> Result<NonZeroU16, <NonZeroU16 as TryFrom<NonZeroU64>>::Error>
Attempts to convert NonZeroU64
to NonZeroU16
.
type Error = TryFromIntError
impl TryFrom<NonZeroU64> for NonZeroU32
fn try_from(
value: NonZeroU64
) -> Result<NonZeroU32, <NonZeroU32 as TryFrom<NonZeroU64>>::Error>
Attempts to convert NonZeroU64
to NonZeroU32
.
type Error = TryFromIntError
impl TryFrom<NonZeroU64> for NonZeroU8
fn try_from(
value: NonZeroU64
) -> Result<NonZeroU8, <NonZeroU8 as TryFrom<NonZeroU64>>::Error>
Attempts to convert NonZeroU64
to NonZeroU8
.
type Error = TryFromIntError
impl TryFrom<NonZeroU64> for NonZeroUsize
fn try_from(
value: NonZeroU64
) -> Result<NonZeroUsize, <NonZeroUsize as TryFrom<NonZeroU64>>::Error>
Attempts to convert NonZeroU64
to NonZeroUsize
.
type Error = TryFromIntError
impl TryFrom<NonZeroUsize> for NonZeroU64
fn try_from(
value: NonZeroUsize
) -> Result<NonZeroU64, <NonZeroU64 as TryFrom<NonZeroUsize>>::Error>
Attempts to convert NonZeroUsize
to NonZeroU64
.
type Error = TryFromIntError
impl TryFrom<u64> for NonZeroU64
fn try_from(
value: u64
) -> Result<NonZeroU64, <NonZeroU64 as TryFrom<u64>>::Error>
Attempts to convert u64
to NonZeroU64
.
type Error = TryFromIntError
impl UpperHex for NonZeroU64
fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>
impl Copy for NonZeroU64
impl Eq for NonZeroU64
impl StructuralEq for NonZeroU64
impl StructuralPartialEq for NonZeroU64
Auto Trait Implementations
impl RefUnwindSafe for NonZeroU64
impl Send for NonZeroU64
impl Sync for NonZeroU64
impl Unpin for NonZeroU64
impl UnwindSafe for NonZeroU64
Blanket Implementations
impl<T> Any for T
where
T: 'static + ?Sized,
impl<T> Borrow<T> for T
where
T: ?Sized,
impl<T> BorrowMut<T> for T
where
T: ?Sized,
impl<T> From<T> for T
fn from(t: T) -> T
Returns the argument unchanged.
impl<T, U> Into<U> for T
where
U: From<T>,
fn into(self) -> U
Calls U::from(self)
.
That is, this conversion is whatever the implementation of From<T> for U
chooses to do.
impl<T> ToOwned for T
where
T: Clone,
type Owned = T
fn to_owned(&self) -> T
fn clone_into(&self, target: &mut T)
impl<T> ToString for T
where
T: Display + ?Sized,
impl<T, U> TryFrom<U> for T
where
U: Into<T>,
type Error = Infallible
fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
impl<T, U> TryInto<U> for T
where
U: TryFrom<T>,
type Error = <U as TryFrom<T>>::Error
fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/num/struct.NonZeroU64.html