Struct core::num::NonZeroIsize 1.34.0[−][src]
#[repr(transparent)]pub struct NonZeroIsize(_);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>());RunImplementations
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::NonZeroIsize::new(-1isize).unwrap();
assert_eq!(n.leading_zeros(), 0);RunReturns 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);RunComputes the absolute value of self.
See isize::abs
for documentation on overflow behaviour.
Example
#![feature(nonzero_ops)]
let pos = NonZeroIsize::new(1)?;
let neg = NonZeroIsize::new(-1)?;
assert_eq!(pos, pos.abs());
assert_eq!(pos, neg.abs());RunChecked absolute value.
Check for overflow and returns None if
self == isize::MIN.
The result cannot be zero.
Example
#![feature(nonzero_ops)]
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());RunComputes the absolute value of self,
with overflow information, see
isize::overflowing_abs.
Example
#![feature(nonzero_ops)]
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());RunSaturating absolute value, see
isize::saturating_abs.
Example
#![feature(nonzero_ops)]
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());RunWrapping absolute value, see
isize::wrapping_abs.
Example
#![feature(nonzero_ops)]
let pos = NonZeroIsize::new(1)?;
let neg = NonZeroIsize::new(-1)?;
let min = NonZeroIsize::new(isize::MIN)?;
let max = NonZeroIsize::new(isize::MAX)?;
assert_eq!(pos, pos.wrapping_abs());
assert_eq!(pos, neg.wrapping_abs());
assert_eq!(min, min.wrapping_abs());RunComputes the absolute value of self without any wrapping or panicking.
Example
#![feature(nonzero_ops)]
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());RunMultiply 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 = 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));RunMultiply two non-zero integers together.
Return isize::MAX on overflow.
Examples
#![feature(nonzero_ops)]
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));RunMultiply 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) });RunRaise 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 = 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));RunRaise non-zero value to an integer power.
Return isize::MIN or isize::MAX on overflow.
Examples
#![feature(nonzero_ops)]
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
type Output = NonZeroIsize
type Output = NonZeroIsize
The resulting type after applying the | operator.
Performs the | operation. Read more
Performs the |= operation. Read more
Performs the |= operation. Read more
Converts NonZeroI16 to NonZeroIsize losslessly.
Converts a NonZeroIsize into an isize
This method tests for self and other values to be equal, and is used
by ==. Read more
This method tests for !=.
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
Attempts to convert NonZeroI128 to NonZeroIsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroI32 to NonZeroIsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroI64 to NonZeroIsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroIsize to NonZeroU8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroIsize to NonZeroU16.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroIsize to NonZeroI128.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroIsize to NonZeroU32.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroIsize to NonZeroU64.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroIsize to NonZeroU128.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroIsize to NonZeroUsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroIsize to NonZeroI8.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroIsize to NonZeroI16.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroIsize to NonZeroI32.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroIsize to NonZeroI64.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroU128 to NonZeroIsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroU16 to NonZeroIsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroU32 to NonZeroIsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroU64 to NonZeroIsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.
Attempts to convert NonZeroUsize to NonZeroIsize.
type Error = TryFromIntError
type Error = TryFromIntError
The type returned in the event of a conversion error.