Type Alias core::num::NonZeroIsize
1.34.0 · source · pub type NonZeroIsize = NonZero<isize>;
Expand description
An integer that is known not to equal zero.
This enables some memory layout optimization.
For example, Option<NonZeroIsize>
is the same size as isize
:
use std::mem::size_of;
assert_eq!(size_of::<Option<core::num::NonZeroIsize>>(), size_of::<isize>());
Run§Layout
NonZeroIsize
is guaranteed to have the same layout and bit validity as isize
with the exception that 0
is not a valid instance.
Option<NonZeroIsize>
is guaranteed to be compatible with isize
,
including in FFI.
Thanks to the null pointer optimization,
NonZeroIsize
and Option<NonZeroIsize>
are guaranteed to have the same size and alignment:
use std::num::NonZeroIsize;
assert_eq!(size_of::<NonZeroIsize>(), size_of::<Option<NonZeroIsize>>());
assert_eq!(align_of::<NonZeroIsize>(), align_of::<Option<NonZeroIsize>>());
RunAliased Type§
struct NonZeroIsize(/* private fields */);
Implementations§
source§impl NonZeroIsize
impl NonZeroIsize
const: 1.34.0 · sourcepub const unsafe fn new_unchecked(n: isize) -> Self
pub const unsafe fn new_unchecked(n: isize) -> 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.
const: 1.47.0 · sourcepub const fn new(n: isize) -> Option<Self>
pub const fn new(n: isize) -> Option<Self>
Creates a non-zero if the given value is not zero.
sourcepub unsafe fn from_mut_unchecked(n: &mut isize) -> &mut Self
🔬This is a nightly-only experimental API. (nonzero_from_mut
#106290)
pub unsafe fn from_mut_unchecked(n: &mut isize) -> &mut Self
nonzero_from_mut
#106290)Converts a primitive mutable reference to a non-zero mutable reference
without checking whether the referenced value is non-zero.
This results in undefined behavior if *n
is zero.
§Safety
The referenced value must not be currently zero.
sourcepub fn from_mut(n: &mut isize) -> Option<&mut Self>
🔬This is a nightly-only experimental API. (nonzero_from_mut
#106290)
pub fn from_mut(n: &mut isize) -> Option<&mut Self>
nonzero_from_mut
#106290)Converts a primitive mutable reference to a non-zero mutable reference if the referenced integer is not zero.
1.67.0 · sourcepub const BITS: u32 = 64u32
pub const BITS: u32 = 64u32
The size of this non-zero integer type in bits.
This value is equal to isize::BITS
.
§Examples
assert_eq!(NonZeroIsize::BITS, isize::BITS);
Run1.53.0 (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::NonZeroIsize::new(-1isize).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::NonZeroIsize::new(0b0101000).unwrap();
assert_eq!(n.trailing_zeros(), 3);
Runconst: unstable · sourcepub fn count_ones(self) -> NonZeroU32
🔬This is a nightly-only experimental API. (non_zero_count_ones
#120287)
pub fn count_ones(self) -> NonZeroU32
non_zero_count_ones
#120287)Returns the number of ones in the binary representation of self
.
§Examples
Basic usage:
#![feature(non_zero_count_ones)]
let one = num::NonZeroU32::new(1)?;
let three = num::NonZeroU32::new(3)?;
let a = NonZeroIsize::new(0b100_0000)?;
let b = NonZeroIsize::new(0b100_0011)?;
assert_eq!(a.count_ones(), one);
assert_eq!(b.count_ones(), three);
Run1.70.0 · sourcepub const MIN: Self = _
pub const MIN: Self = _
The smallest value that can be represented by this non-zero
integer type,
equal to isize::MIN
.
Note: While most integer types are defined for every whole
number between MIN
and MAX
, signed non-zero integers are
a special case. They have a “gap” at 0.
§Examples
assert_eq!(NonZeroIsize::MIN.get(), isize::MIN);
Run1.70.0 · sourcepub const MAX: Self = _
pub const MAX: Self = _
The largest value that can be represented by this non-zero
integer type,
equal to isize::MAX
.
Note: While most integer types are defined for every whole
number between MIN
and MAX
, signed non-zero integers are
a special case. They have a “gap” at 0.
§Examples
assert_eq!(NonZeroIsize::MAX.get(), isize::MAX);
Run1.64.0 (const: 1.64.0) · sourcepub const fn abs(self) -> Self
pub const fn abs(self) -> Self
Computes the absolute value of self.
See isize::abs
for documentation on overflow behaviour.
§Example
let pos = NonZeroIsize::new(1)?;
let neg = NonZeroIsize::new(-1)?;
assert_eq!(pos, pos.abs());
assert_eq!(pos, neg.abs());
Run1.64.0 (const: 1.64.0) · sourcepub const fn checked_abs(self) -> Option<Self>
pub const fn checked_abs(self) -> Option<Self>
Checked absolute value.
Checks for overflow and returns None
if
self == NonZeroIsize::MIN
.
The result cannot be zero.
§Example
let pos = NonZeroIsize::new(1)?;
let neg = NonZeroIsize::new(-1)?;
let min = NonZeroIsize::new(isize::MIN)?;
assert_eq!(Some(pos), neg.checked_abs());
assert_eq!(None, min.checked_abs());
Run1.64.0 (const: 1.64.0) · sourcepub const fn overflowing_abs(self) -> (Self, bool)
pub const fn overflowing_abs(self) -> (Self, bool)
Computes the absolute value of self,
with overflow information, see
isize::overflowing_abs
.
§Example
let pos = NonZeroIsize::new(1)?;
let neg = NonZeroIsize::new(-1)?;
let min = NonZeroIsize::new(isize::MIN)?;
assert_eq!((pos, false), pos.overflowing_abs());
assert_eq!((pos, false), neg.overflowing_abs());
assert_eq!((min, true), min.overflowing_abs());
Run1.64.0 (const: 1.64.0) · sourcepub const fn saturating_abs(self) -> Self
pub const fn saturating_abs(self) -> Self
Saturating absolute value, see
isize::saturating_abs
.
§Example
let pos = NonZeroIsize::new(1)?;
let neg = NonZeroIsize::new(-1)?;
let min = NonZeroIsize::new(isize::MIN)?;
let min_plus = NonZeroIsize::new(isize::MIN + 1)?;
let max = NonZeroIsize::new(isize::MAX)?;
assert_eq!(pos, pos.saturating_abs());
assert_eq!(pos, neg.saturating_abs());
assert_eq!(max, min.saturating_abs());
assert_eq!(max, min_plus.saturating_abs());
Run1.64.0 (const: 1.64.0) · sourcepub const fn wrapping_abs(self) -> Self
pub const fn wrapping_abs(self) -> Self
Wrapping absolute value, see
isize::wrapping_abs
.
§Example
let pos = NonZeroIsize::new(1)?;
let neg = NonZeroIsize::new(-1)?;
let min = NonZeroIsize::new(isize::MIN)?;
assert_eq!(pos, pos.wrapping_abs());
assert_eq!(pos, neg.wrapping_abs());
assert_eq!(min, min.wrapping_abs());
assert_eq!(max, (-max).wrapping_abs());
Run1.64.0 (const: 1.64.0) · sourcepub const fn unsigned_abs(self) -> NonZeroUsize
pub const fn unsigned_abs(self) -> NonZeroUsize
Computes the absolute value of self without any wrapping or panicking.
§Example
let u_pos = NonZeroUsize::new(1)?;
let i_pos = NonZeroIsize::new(1)?;
let i_neg = NonZeroIsize::new(-1)?;
let i_min = NonZeroIsize::new(isize::MIN)?;
let u_max = NonZeroUsize::new(usize::MAX / 2 + 1)?;
assert_eq!(u_pos, i_pos.unsigned_abs());
assert_eq!(u_pos, i_neg.unsigned_abs());
assert_eq!(u_max, i_min.unsigned_abs());
Run1.71.0 (const: 1.71.0) · sourcepub const fn is_positive(self) -> bool
pub const fn is_positive(self) -> bool
1.71.0 (const: 1.71.0) · sourcepub const fn is_negative(self) -> bool
pub const fn is_negative(self) -> bool
1.71.0 (const: 1.71.0) · sourcepub const fn checked_neg(self) -> Option<Self>
pub const fn checked_neg(self) -> Option<Self>
1.71.0 (const: 1.71.0) · sourcepub const fn overflowing_neg(self) -> (Self, bool)
pub const fn overflowing_neg(self) -> (Self, bool)
Negates self, overflowing if this is equal to the minimum value.
See isize::overflowing_neg
for documentation on overflow behaviour.
§Example
let pos_five = NonZeroIsize::new(5)?;
let neg_five = NonZeroIsize::new(-5)?;
let min = NonZeroIsize::new(isize::MIN)?;
assert_eq!(pos_five.overflowing_neg(), (neg_five, false));
assert_eq!(min.overflowing_neg(), (min, true));
Run1.71.0 (const: 1.71.0) · sourcepub const fn saturating_neg(self) -> Self
pub const fn saturating_neg(self) -> Self
Saturating negation. Computes -self
,
returning NonZeroIsize::MAX
if self == NonZeroIsize::MIN
instead of overflowing.
§Example
let pos_five = NonZeroIsize::new(5)?;
let neg_five = NonZeroIsize::new(-5)?;
let min = NonZeroIsize::new(isize::MIN)?;
let min_plus_one = NonZeroIsize::new(isize::MIN + 1)?;
let max = NonZeroIsize::new(isize::MAX)?;
assert_eq!(pos_five.saturating_neg(), neg_five);
assert_eq!(min.saturating_neg(), max);
assert_eq!(max.saturating_neg(), min_plus_one);
Run1.71.0 (const: 1.71.0) · sourcepub const fn wrapping_neg(self) -> Self
pub const fn wrapping_neg(self) -> Self
Wrapping (modular) negation. Computes -self
, wrapping around at the boundary
of the type.
See isize::wrapping_neg
for documentation on overflow behaviour.
§Example
let pos_five = NonZeroIsize::new(5)?;
let neg_five = NonZeroIsize::new(-5)?;
let min = NonZeroIsize::new(isize::MIN)?;
assert_eq!(pos_five.wrapping_neg(), neg_five);
assert_eq!(min.wrapping_neg(), min);
Run1.64.0 (const: 1.64.0) · sourcepub const fn checked_mul(self, other: Self) -> Option<Self>
pub const fn checked_mul(self, other: Self) -> Option<Self>
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 = NonZeroIsize::new(2)?;
let four = NonZeroIsize::new(4)?;
let max = NonZeroIsize::new(isize::MAX)?;
assert_eq!(Some(four), two.checked_mul(two));
assert_eq!(None, max.checked_mul(two));
Run1.64.0 (const: 1.64.0) · sourcepub const fn saturating_mul(self, other: Self) -> Self
pub const fn saturating_mul(self, other: Self) -> Self
Multiplies two non-zero integers together.
Return NonZeroIsize::MAX
on overflow.
§Examples
let two = NonZeroIsize::new(2)?;
let four = NonZeroIsize::new(4)?;
let max = NonZeroIsize::new(isize::MAX)?;
assert_eq!(four, two.saturating_mul(two));
assert_eq!(max, four.saturating_mul(max));
Runsourcepub const unsafe fn unchecked_mul(self, other: Self) -> Self
🔬This is a nightly-only experimental API. (nonzero_ops
#84186)
pub const unsafe fn unchecked_mul(self, other: Self) -> Self
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 > isize::MAX
, or self * rhs < isize::MIN
.
§Examples
#![feature(nonzero_ops)]
let two = NonZeroIsize::new(2)?;
let four = NonZeroIsize::new(4)?;
assert_eq!(four, unsafe { two.unchecked_mul(two) });
Run1.64.0 (const: 1.64.0) · sourcepub const fn checked_pow(self, other: u32) -> Option<Self>
pub const fn checked_pow(self, other: u32) -> Option<Self>
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 = NonZeroIsize::new(3)?;
let twenty_seven = NonZeroIsize::new(27)?;
let half_max = NonZeroIsize::new(isize::MAX / 2)?;
assert_eq!(Some(twenty_seven), three.checked_pow(3));
assert_eq!(None, half_max.checked_pow(3));
Run1.64.0 (const: 1.64.0) · sourcepub const fn saturating_pow(self, other: u32) -> Self
pub const fn saturating_pow(self, other: u32) -> Self
Raise non-zero value to an integer power.
Return NonZeroIsize::MIN
or NonZeroIsize::MAX
on overflow.
§Examples
let three = NonZeroIsize::new(3)?;
let twenty_seven = NonZeroIsize::new(27)?;
let max = NonZeroIsize::new(isize::MAX)?;
assert_eq!(twenty_seven, three.saturating_pow(3));
assert_eq!(max, max.saturating_pow(3));
RunTrait Implementations§
source§impl Binary for NonZeroIsize
impl Binary for NonZeroIsize
1.45.0 · source§impl BitOr<isize> for NonZeroIsize
impl BitOr<isize> for NonZeroIsize
1.45.0 · source§impl BitOr for NonZeroIsize
impl BitOr for NonZeroIsize
1.45.0 · source§impl BitOrAssign<isize> for NonZeroIsize
impl BitOrAssign<isize> for NonZeroIsize
source§fn bitor_assign(&mut self, rhs: isize)
fn bitor_assign(&mut self, rhs: isize)
|=
operation. Read more1.45.0 · source§impl BitOrAssign for NonZeroIsize
impl BitOrAssign for NonZeroIsize
source§fn bitor_assign(&mut self, rhs: Self)
fn bitor_assign(&mut self, rhs: Self)
|=
operation. Read moresource§impl Clone for NonZeroIsize
impl Clone for NonZeroIsize
source§impl Debug for NonZeroIsize
impl Debug for NonZeroIsize
source§impl Display for NonZeroIsize
impl Display for NonZeroIsize
1.41.0 · source§impl From<NonZero<i16>> for NonZeroIsize
impl From<NonZero<i16>> for NonZeroIsize
source§fn from(small: NonZeroI16) -> Self
fn from(small: NonZeroI16) -> Self
Converts NonZeroI16
to NonZeroIsize
losslessly.
1.35.0 · source§impl FromStr for NonZeroIsize
impl FromStr for NonZeroIsize
source§impl Hash for NonZeroIsize
impl Hash for NonZeroIsize
source§impl LowerHex for NonZeroIsize
impl LowerHex for NonZeroIsize
1.71.0 · source§impl Neg for &NonZeroIsize
impl Neg for &NonZeroIsize
1.71.0 · source§impl Neg for NonZeroIsize
impl Neg for NonZeroIsize
source§impl Octal for NonZeroIsize
impl Octal for NonZeroIsize
source§impl PartialEq for NonZeroIsize
impl PartialEq for NonZeroIsize
source§impl PartialOrd for NonZeroIsize
impl PartialOrd for NonZeroIsize
1.49.0 · source§impl TryFrom<NonZero<i128>> for NonZeroIsize
impl TryFrom<NonZero<i128>> for NonZeroIsize
source§fn try_from(value: NonZeroI128) -> Result<Self, Self::Error>
fn try_from(value: NonZeroI128) -> Result<Self, Self::Error>
Attempts to convert NonZeroI128
to NonZeroIsize
.
§type Error = TryFromIntError
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZero<i32>> for NonZeroIsize
impl TryFrom<NonZero<i32>> for NonZeroIsize
source§fn try_from(value: NonZeroI32) -> Result<Self, Self::Error>
fn try_from(value: NonZeroI32) -> Result<Self, Self::Error>
Attempts to convert NonZeroI32
to NonZeroIsize
.
§type Error = TryFromIntError
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZero<i64>> for NonZeroIsize
impl TryFrom<NonZero<i64>> for NonZeroIsize
source§fn try_from(value: NonZeroI64) -> Result<Self, Self::Error>
fn try_from(value: NonZeroI64) -> Result<Self, Self::Error>
Attempts to convert NonZeroI64
to NonZeroIsize
.
§type Error = TryFromIntError
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZero<u128>> for NonZeroIsize
impl TryFrom<NonZero<u128>> for NonZeroIsize
source§fn try_from(value: NonZeroU128) -> Result<Self, Self::Error>
fn try_from(value: NonZeroU128) -> Result<Self, Self::Error>
Attempts to convert NonZeroU128
to NonZeroIsize
.
§type Error = TryFromIntError
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZero<u16>> for NonZeroIsize
impl TryFrom<NonZero<u16>> for NonZeroIsize
source§fn try_from(value: NonZeroU16) -> Result<Self, Self::Error>
fn try_from(value: NonZeroU16) -> Result<Self, Self::Error>
Attempts to convert NonZeroU16
to NonZeroIsize
.
§type Error = TryFromIntError
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZero<u32>> for NonZeroIsize
impl TryFrom<NonZero<u32>> for NonZeroIsize
source§fn try_from(value: NonZeroU32) -> Result<Self, Self::Error>
fn try_from(value: NonZeroU32) -> Result<Self, Self::Error>
Attempts to convert NonZeroU32
to NonZeroIsize
.
§type Error = TryFromIntError
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZero<u64>> for NonZeroIsize
impl TryFrom<NonZero<u64>> for NonZeroIsize
source§fn try_from(value: NonZeroU64) -> Result<Self, Self::Error>
fn try_from(value: NonZeroU64) -> Result<Self, Self::Error>
Attempts to convert NonZeroU64
to NonZeroIsize
.
§type Error = TryFromIntError
type Error = TryFromIntError
1.49.0 · source§impl TryFrom<NonZero<usize>> for NonZeroIsize
impl TryFrom<NonZero<usize>> for NonZeroIsize
source§fn try_from(value: NonZeroUsize) -> Result<Self, Self::Error>
fn try_from(value: NonZeroUsize) -> Result<Self, Self::Error>
Attempts to convert NonZeroUsize
to NonZeroIsize
.